Testing for intolerances: which procedure answers which question
The essentials at a glance
There is no test for “intolerances.” The word covers several physically different processes, each of which is examined differently: a missing enzyme using a breath test, celiac disease using antibodies in the blood and a tissue sample, and a true allergy using specific IgE together with the medical history. Anyone who chooses the wrong procedure gets a result that does not answer their question.
This article organizes the procedures according to the cause they can actually detect. Every statement includes the institution and year. Where a professional society advises against a procedure, that is stated here in the original wording rather than in a footnote.
You will first read what the word encompasses and how common the individual causes are. This is followed by the evidentiary value of a finding, the signs that warrant an appointment before any test, three common assumptions, the chapters on lactose, celiac disease, and IgE-mediated allergy, a comparison of the three procedures, an assessment of IgG tests, and the limitations.
What to expect in this article
1. What the word “intolerance” encompasses
2. How common the individual causes actually are
3. What a test result proves and what it does not
4. When symptoms should first be taken to a doctor’s office
5. Three common assumptions and what is supported by evidence
6. Lactose: when an enzyme is missing
7. Three procedures, three different questions
8. Celiac disease: why gluten remains on the plate before testing
9. IgE-mediated allergy: what a finding shows
10. Who may be considered for an IgE test and who may not
11. IgG tests for foods: what applies to them
12. From suspicion to a useful finding
13. What a capillary blood test at home covers
14. Limitations: what testing for intolerances cannot do
15. What ultimately matters when testing
Frequently asked questions
Sources
What the word “intolerance” encompasses
People who want to test for intolerances usually have a very specific question in mind: Which food is causing my symptoms? The question is valid. It simply cannot be answered with a single procedure, and that is because of the word itself.
“Intolerance” is not a medical finding but an everyday description. It says that something happens after eating. It says nothing about what takes place in the body. Yet that exact process determines which examination can find anything at all.
Three processes that have the same name in everyday language
The first process is a matter of digestion. A sugar from food is not broken down and absorbed, or is only partially broken down and absorbed, travels on to the large intestine, and is fermented there by bacteria. The immune system is not involved. The best-known example is lactose.
The second process is an autoimmune disease. In coeliac disease, after contact with gluten, the immune system attacks the lining of the small intestine. The Institute for Quality and Efficiency in Health Care (IQWiG) describes it as gluten not being tolerated “and causing inflammation of the intestinal lining” (IQWiG, 2022).
The third process is a true allergy. Here, the immune system produces class E antibodies, or IgE for short, against a protein from food. The reaction usually occurs quickly and can be triggered by even small amounts.
Apart from the trigger, these three processes have little in common. They differ in the amount that causes symptoms, the speed of the reaction, and, above all, what can actually be detected.
Why the Search Engine Lumps Everything Together
When searching for a test, it does not begin with a medical term but with a gut feeling. That is why people whose symptoms have four different causes end up under the same search term, and they all see the same offers.
The fourth case belongs here even though it is harder to define: a sensitivity to wheat without coeliac disease and without an allergy. The IQWiG describes it as “sensitivity to components of wheat that does not, however, lead to pathological changes in the intestinal lining” (IQWiG, 2022).
There is no laboratory procedure that can detect this fourth case. The IQWiG states: “If wheat sensitivity is suspected, it is important first to rule out coeliac disease or an allergy.” (IQWiG, 2022) The path therefore involves ruling conditions out, not using a test of its own.
What this means for the testing question
This reverses the order. It is not the test that tells you which cause is present; rather, the suspected cause determines which test is even appropriate. That may sound inconvenient, but it saves money and weeks of time.
If the symptoms seem to come more from the digestive tract and are less tied to individual foods, it is worth taking a different look first. You can look up which types of bacteria and markers may occur in a stool analysis in the Gut Encyclopedia.
How common the individual causes actually are
The frequencies differ widely, and this gap itself indicates where it makes sense to begin an evaluation. Three figures from three documented sources are shown side by side, all as a proportion of the population.
Three Causes, Three Orders of Magnitude
5–15 %
of people from Europe cannot tolerate lactose (IQWiG, 2024)
1–2 %
of people in Europe have confirmed celiac disease (IQWiG, 2022)
3,7 %
of adults had a food allergy in a study confirmed by food challenge (DGAKI et al., 2021)
Source: IQWiG 2024 and 2022, DGAKI and other medical societies 2021
The figure for food allergy comes from the specialist guideline issued by the allergy societies. It states verbatim: “A 2004 study found a prevalence of food allergy, confirmed by double-blind, placebo-controlled food challenge, of 3.7% in adults and 4.2% in children.” (DGAKI and other medical societies, 2021)
The note about the challenge test carries this point. It refers to the controlled administration of the suspected food under medical supervision, without the participants knowing who receives what and when. Figures from surveys alone are regularly much higher than figures from such tests.
Why the lactose figure varies so widely
With lactose, the range is striking, and it has a geographical reason. IQWiG states: “About 5% to 15% of people from Europe cannot tolerate lactose.” (IQWiG, 2024) The same source gives entirely different figures for other regions of the world.
It states: “In Africa or East Asia, by contrast, 65% to more than 90% of adults are affected.” (IQWiG, 2024) Worldwide, people who can still digest lactose in adulthood are therefore more the exception than the rule.
For the testing question, this is more than a side note. Symptoms after consuming dairy products are not uncommon in Europe, but they are not the norm either. They occur often enough to warrant checking first, before more elaborate procedures are started.
What a test result proves—and what it does not
A laboratory value is a measurement, not a diagnosis. This distinction is the most important point in the entire topic, and it is stated so clearly in the specialist guideline on food allergies that it belongs here verbatim.
Documented source
“Detecting sensitization through specific IgE testing or a skin prick test does not prove the clinical relevance of the food tested and should not, by itself, lead to therapeutic elimination.”
German Society for Allergology and Clinical Immunology (DGAKI), together with other medical societies
Updated guideline on the management of IgE-mediated food allergies, AWMF Registry No. 061-031, 2021
The sentence consists of two parts, and the second is the more practically important one. A positive result does not prove that this food is causing your symptoms. And by itself, it is not a reason to permanently remove it from your diet.
Sensitization means that the immune system has produced antibodies. Whether this leads to a reaction is determined by the symptoms, not in the laboratory. People can have measurable antibodies and eat without symptoms throughout their lives.
The reverse case is not clear-cut either
An unremarkable result is likewise not a strict all-clear. The guideline puts it this way: “The absence of detectable sensitization (negative specific IgE/skin prick test) frequently, but not definitively, rules out a clinically relevant IgE-mediated food allergy.” (DGAKI and other professional societies, 2021)
Often, but not always. Two words that mark the difference between an indication and proof. If you continue to react after a negative result, you have not received a false result, but an incomplete answer.
What the assessment actually begins with
That is why it does not start with a tube, but with a conversation. The guideline places this at the beginning of its diagnostic chapter: “A detailed medical history should form the basis for diagnosing food allergy.” (DGAKI and other professional societies, 2021)
Medical history means what you ate, how quickly the reaction occurred, what it looked like, and how often it recurred. A test puts these observations into context. It does not replace them.
Key message
An antibody result indicates sensitization. Whether this leads to a reaction to a food is determined by the medical history together with the test result, not by the value alone.
When symptoms should first be assessed at a medical practice
Before ordering any test, the question is whether the symptoms are consistent with an intolerance at all. Some signs answer this question by themselves—with a no.
Blood in the stool requires a visit to a medical practice. Unintentional weight loss requires a visit to a medical practice. Persistent fever requires a visit to a medical practice. Symptoms that wake you from sleep at night require a visit to a medical practice.
There is also one sign that is specific to this issue. A reaction that occurs within minutes and affects the skin, breathing, or circulation is not a case for a test ordered online, but an emergency. Swelling in the mouth and throat, difficulty breathing, and circulatory problems after eating require immediate medical attention.
These signs are not a reason to start an elimination phase and not a reason to place an order. They are a reason to make an appointment. If you notice them, do not test—see a doctor.
The reason lies in exclusion
Abdominal symptoms after eating can be caused by conditions that have nothing to do with food. A test for antibodies against foods is looking for something else and therefore does not detect them.
That is the real harm of a test performed at the wrong time: It answers a question no one asked and provides reassurance about one that remains unanswered. An unremarkable result can cause a necessary appointment to be postponed for months.
Three common assumptions and what the evidence shows
Three ideas repeatedly come up in conversations on this topic. All three are understandable, and all three conflict with what professional societies and institutes have published on the subject.
Assumption and evidence
Common
“A blood test tells me which foods I cannot tolerate.”
Supported by evidence
For IgG and IgG4 antibodies against foods, the joint assessment by the allergy societies is as follows: The test is “unsuitable for evaluating and diagnosing food intolerances and must be strictly rejected” (Kleine-Tebbe and colleagues, Allergo Journal, 2009).
Common
“Lactose intolerance is an allergy to milk.”
Supported by evidence
“Lactose intolerance is not an allergy.” (IQWiG, 2024) According to the same source, people with a milk allergy react even to the smallest amounts, whereas people with lactose intolerance can tolerate certain amounts.
Common
“I’ll avoid gluten for now and test later to see whether it was celiac disease.”
Supported by evidence
“The test is meaningful only if sufficient gluten has been consumed beforehand.” (IQWiG, 2022) Eliminating gluten beforehand makes subsequent evaluation more difficult.
All three assumptions have the same core: They expect the laboratory to provide an answer it cannot provide. In all three cases, the way forward is to observe your own everyday life and choose the appropriate method.
Lactose: when an enzyme is missing
Lactose is broken down by an enzyme in the small intestine so that it can be absorbed at all. If too little of the enzyme is present, the sugar continues into the large intestine. There, bacteria ferment it, producing gases.
This explains the typical pattern of symptoms. IQWiG states: “After consuming milk and products containing lactose, many people experience digestive problems such as abdominal pain, bloating, or diarrhea.” (IQWiG, 2024)
The key issue is quantity. IQWiG states that people who have difficulty digesting dairy products may “possibly tolerate lactose only in small amounts” (IQWiG, 2024). So it is rarely a matter of a complete ban; rather, it is about an individual threshold.
Why a breath test measures here instead of a blood test
Because no antibody is involved, there is no antibody to measure. Instead, the test measures the gas produced during fermentation and exhaled through the lungs.
IQWiG describes the method as follows: “Breath test: After drinking a lactose solution, the hydrogen content in the exhaled air is measured several times.” (IQWiG, 2024) “Several times” is the key phrase here, because the pattern over time provides the information, not a single value.
This test is carried out at a medical practice and takes time. That is the price of measuring the process in question. An antibody level from a blood test cannot reflect this process, no matter how many foods are listed in the test result.
How you can investigate the question in everyday life before an appointment is scheduled is explained in our article Recognizing lactose intolerance. This article focuses on which method detects which cause.
What the material used says about other sugars
Alongside lactose, fructose is also regularly mentioned when it comes to symptoms after eating. The source material reviewed for this article contains no separate information on this, including an institution and year.
That is why there is no number or method description here. If fructose is suspected in your case, the question belongs in the same practice that also offers the lactose breath test, not in an antibody test result.
Three methods, three different questions
The following overview places the three pathways side by side according to the same criteria. It does not rank them by effort or price, but by which question each method answers and which it leaves open.
| Criterion | Enzyme deficiency, e.g. lactose | Celiac disease | IgE-mediated allergy |
|---|---|---|---|
| What happens in the body | A sugar is not broken down sufficiently and is fermented in the large intestine. The immune system is not involved. | Gluten is not tolerated “and inflammation of the intestinal lining” is triggered (IQWiG, 2022). | The immune system produces IgE antibodies against a food protein. The reaction is usually rapid and can occur with even small amounts. |
| What is tested | “Breath test: After drinking a lactose solution, the hydrogen content in the exhaled air is measured several times.” (IQWiG, 2024) | IgA antibodies against tissue transglutaminase in the blood, usually along with “tissue samples from the upper small intestine, generally obtained during a gastroscopy” (IQWiG, 2022). | Medical history, specific IgE and skin prick test, and, if necessary, a challenge test (DGAKI et al., 2021). |
| What to bear in mind before the test | The test is carried out at a medical practice and requires several measurements over a period of time. | “The test is only meaningful if sufficient gluten has been consumed beforehand.” (IQWiG, 2022) | The medical history is part of it: “A detailed medical history should form the basis for diagnosing food allergies.” (DGAKI et al., 2021) |
| What the result alone indicates | It describes the digestion of the sugar. It does not determine the amount an individual can tolerate. | The diagnosis arises from the blood value and tissue sample together, not from a single value. | It shows sensitization. It “does not prove the clinical relevance of the food tested” (DGAKI et al., 2021). |
| Where the examination takes place | In a medical practice, because measurements are taken over several hours. | Blood sampling and gastroscopy, that is, arranged by a doctor. | Medical; IgE measurement is also possible from capillary blood, but the interpretation remains medical. |
A fourth column is deliberately missing from this table. Tests for IgG antibodies against foods do not belong alongside these three procedures because they do not answer a question left open by them. Why this is so is explained in Chapter 11.
Celiac disease: why gluten remains on the plate before the test
Celiac disease is the exceptional case among the three causes, and it is the only one where incorrect preparation makes the result unusable. That is why it gets its own chapter here.
Regarding frequency, IQWiG states: “Approximately 1 to 2% of people in Europe have confirmed celiac disease.” (IQWiG, 2022) That is rare enough to be overlooked and common enough to be relevant when symptoms persist.
Two tests that belong together
The first step is a blood test. According to IQWiG, the test looks for “immunoglobulin A (IgA) antibodies against a specific enzyme, known as tissue transglutaminase (tTG or TG2)” (IQWiG, 2022).
The second step concerns the tissue itself. IQWiG states: “In addition to the blood test, tissue samples are generally taken from the upper small intestine during a gastroscopy.” (IQWiG, 2022) Only the two steps together support the diagnosis.
This also makes clear what an antibody level alone can and cannot do. It is an indication that points the way forward. A diagnosis arises only in the medical context, and this context cannot be established at home.
The most common mistake
When gluten is suspected, it seems logical to eliminate it immediately. That is precisely the mistake. IQWiG states: “The test is only meaningful if sufficient gluten has been consumed beforehand.” (IQWiG, 2022)
The reason lies in how it works. Both tests look for the reaction to gluten. If the trigger is absent for weeks, the antibodies decrease and the mucous membrane recovers. The findings then appear normal, even though celiac disease is present.
Anyone who is already eating gluten-free but still wants clarity should therefore discuss the sequence with a doctor before testing. Reintroducing gluten on your own is not a good idea if the symptoms were previously severe. A more detailed explanation can be found in our article Celiac disease test.
Chapter at a glance
According to IQWiG (2022), around 1 to 2 percent of people in Europe have celiac disease. Testing is performed in two stages: IgA antibodies against tissue transglutaminase in the blood, plus tissue samples from the upper small intestine obtained through a gastroscopy. Both tests require sufficient gluten consumption beforehand because they look for the reaction to gluten. Anyone who eliminates gluten as a precaution makes subsequent assessment more difficult.
IgE-mediated allergy: what a test result shows
A true food allergy is the only one of the three pathways in which an antibody in the blood actually corresponds to the underlying process. That is why IgE testing is recognized diagnostics here and not merely an indication.
The clinical guideline describes the assessment as an interplay of several building blocks: medical history, evidence of sensitization through specific IgE or a skin-prick test, assessment of clinical relevance, and, if necessary, a provocation test (DGAKI and other professional societies, 2021).
The test result is therefore one of several building blocks. It comes early in the process because it can be measured broadly and without much effort. It does not come at the end because it cannot answer the question of its significance in everyday life on its own.
Why a positive result does not yet justify a diet
The sentence from Chapter 3 applies once again here because it becomes practical at this point. Evidence of sensitization “should not alone lead to therapeutic elimination” (DGAKI and other professional societies, 2021).
Here, elimination means permanently avoiding the food. Anyone who does this based on a single value may be cutting out something they tolerate without problems. In children and with staple foods, this can create a problem of its own.
Conversely, a finding with many abnormal values does not mean that you have many allergies. It initially means that your immune system has reacted to several proteins. Which of them matter in everyday life is determined by considering the overall picture together with your observations.
Cross-reactions as a common explanation
Some of the abnormal food-related values are due to similarities between proteins. People who react to certain pollens may also react to related proteins in fruit or nuts because their structures are similar.
For you, this means: A finding can explain why an apple makes your mouth tingle in spring but not in winter. An allergology practice puts such patterns into context. A numerical value alone does not.
Who should consider an IgE test and who should not
Whether a specific IgE test will help you depends less on the severity of your symptoms than on their pattern. The following comparison outlines both directions with sound reasons.
Useful for you if …
your reaction begins soon after eating and affects the skin, mucous membranes, or airways—in other words, it matches the pattern of an IgE-mediated reaction.
you already have a specific food in mind and want to put your suspicion into perspective before your doctor’s appointment.
you have written down your observations and understand the result as preparation for a discussion, not as a diagnosis.
Not usually, if …
your symptoms affect only the digestive tract and occur hours after the meal. In that case, an approach focusing on enzyme or absorption disorders is more appropriate.
you suspect gluten is the cause. This question is addressed by the celiac disease evaluation, which requires different preparation.
one of the warning signs from Chapter 4 applies to you. In that case, you need an appointment, not a test.
Our article How much does an allergy test cost explains how much an allergy test costs in a medical practice and laboratory and how it is carried out there. If your concern is digestive symptoms rather than individual foods, At-home gut test categorizes the relevant procedures, while Diet for irritable bowel syndrome describes what the guidelines say about nutrition.
IgG tests for foods: what applies
One method is missing from the overview in Chapter 7—and it happens to be the one most frequently advertised online: testing for IgG antibodies against many foods at once. This omission is not accidental.
IgG is a different antibody class from IgE. Both belong to the immune system, but they represent different processes and must not be interpreted as two variants of the same test. An IgG result is not an allergy test, and an allergy test is not an IgG result.
The allergy specialist societies have issued a joint statement on these tests. Their assessment reads verbatim: “Therefore, the allergen-specific detection of IgG or IgG4 antibodies against foods is unsuitable for the evaluation and diagnosis of food intolerances and must be strictly rejected.” (Kleine-Tebbe et al., Allergo Journal, 2009)
The statement is based on a report by a working group of the European Academy of Allergy and Clinical Immunology and was adopted by the professional societies in Germany, Austria, and Switzerland. It is therefore not an individual opinion.
The mandatory notice we place at the beginning of every text on this subject
The allergy societies do not recommend IgG tests for diagnosing food intolerances. Elevated IgG levels indicate contact with a food, not necessarily an intolerance.
That is the key point for understanding such a finding. An elevated level documents that your body recognizes the food. For foods you eat often, that is normal and not a warning sign.
At most, such a finding can serve as a starting point for a structured food diary: an indication of which foods to observe first during an elimination phase. This is most useful with the support of a nutrition professional. It establishes nothing and proves nothing.
This classification leads to an editorial decision that should be stated openly here: This article contains no offer or link for IgG tests. A text that cites the assessment of the professional societies and then offers the corresponding product undermines its own message.
From suspicion to a useful finding
Several weeks lie between the initial suspicion and a reliable finding. This is not a sign of an unnecessarily complicated approach, but the price of ultimately obtaining a finding that can be acted on.
Write it down instead of eliminating foods
For several weeks, note what you eat, when the symptom occurs, and what it feels like. Without times, it will not be possible to match a symptom to a meal later.
Discussing your medical history
“A detailed medical history should form the basis for diagnosing food allergies.” (DGAKI et al., 2021) It determines which approach is appropriate in the first place.
Choose the test based on the cause
A breath test if an enzyme deficiency is suspected, serology and a tissue sample if celiac disease is suspected, and specific IgE if an allergy is suspected.
Putting findings and everyday life together
Only the overall picture of the result and the observation provides a meaningful conclusion. A result on its own does not justify permanently eliminating a food.
The second step is the one many people skip because it looks like a detour. It is the shortest route to the right test, because it narrows three possibilities down to one.
A diary that only lists foods is of little help. It becomes useful when, in addition to the food, it records the time, the type and severity of the symptoms, and everything else that shaped the day. Four weeks is a good period because it also reveals fluctuations unrelated to food.
What a home capillary blood test covers
mybody®x (MYBODY Lab GmbH) offers a capillary blood test for the third of the three pathways, namely IgE-mediated allergy. Before adding the card for it, the limitation should come first.
The test measures specific IgE. It therefore answers neither the question of an enzyme deficiency nor that of celiac disease. There is no equivalent in the range for a lactose breath test, and a self-test for celiac disease does not replace the two-stage medical assessment involving blood values and a tissue sample.
And the statement from Chapter 3 also applies to this result: Evidence of sensitization does not prove the clinical significance of the food tested. The price is as of 27 August 2026.
Capillary blood test
AllergoCheck | Food and allergy test
Measures specific IgE against 54 of the most common allergens, including foods, pollen, house dust, and animal dander. Product page information, accessed 27 August 2026. What the test cannot do: It does not make a diagnosis, detect an enzyme deficiency such as lactose intolerance, or detect celiac disease, and an abnormal result indicates sensitization, not necessarily symptoms. According to the product page, whether this amounts to an allergy depends on the symptoms and should be assessed by a medical professional.
Laboratory evaluation 3–5 business days after receipt of the sample
Product page information, accessed 27 August 2026
What such a result is useful for in everyday life
Most useful as preparation. Anyone who goes to a medical practice with a result and a diary brings two things that would otherwise first have to be recorded there. This does not shorten an appointment, but it makes it more focused.
What it does not replace is the assessment itself. The clinical guideline calls for a combination of medical history, evidence of sensitization, and, where necessary, a provocation test. For good reason, the final step takes place under medical supervision.
Limitations: what testing cannot do for intolerances
The first boundary comes at the beginning of any honest assessment. No method in this article is a treatment. A test measures something, and what follows from that measurement is decided afterward.
The second limitation lies in the scope. Each of the three methods captures exactly one process. There is no method that covers all four cases from Chapter 1 at once, and the claim that it does is itself a warning sign.
The third limitation concerns the significance of a value. According to clinical guidelines, evidence of sensitization does not prove the clinical relevance of the food tested (DGAKI and other professional societies, 2021). A finding without a medical history is therefore only half the information.
The fourth limitation concerns non-celiac wheat sensitivity. There is no laboratory method for it, only the process of ruling out celiac disease and allergy (IQWiG, 2022). Anyone looking for a test in this case is looking for something that does not exist.
Key message
Each method answers exactly one question. A test that promises to clarify all intolerances at once promises something that none of the cited professional sources considers possible.
What ultimately matters when testing
A short sequence can be derived from four causes and three methods. Observe before testing. Cause before method. Conversation before ordering. Overall assessment before elimination list.
What stands out here appears in none of the cited sources and nevertheless emerges from all of them: The professional societies are less interested in the result than in the question that comes before it. They do not say which value is correct. They say which question a value can answer at all.
The specific next step is therefore smaller than expected and costs nothing. Get a booklet and write down for four weeks what you eat, when symptoms occur, and what they are like. This booklet determines which of the three methods is even suitable for you.
It began with the question of which test can tell you what you cannot tolerate. That is precisely why it is worth taking the detour via the booklet: In the end, there is an answer, but it does not come from the laboratory alone.
If you are not sure which of the three approaches fits your symptoms: The consultation is free, and nothing will be sold to you.
Frequently asked questions
How can I get food intolerances tested?
Not with one single method, but with the one that fits the suspected cause. If an enzyme deficiency is suspected, what is produced during fermentation is measured: “After drinking a lactose solution, the hydrogen level in the exhaled air is measured several times.” (IQWiG, 2024) If celiac disease is suspected, IgA antibodies against tissue transglutaminase are determined, and tissue samples are also taken from the upper small intestine (IQWiG, 2022). If a true allergy is suspected, the evaluation is based on medical history, specific IgE or a skin prick test, and, if necessary, a provocation test (DGAKI and other professional societies, 2021).
Can a blood test show which foods I cannot tolerate?
No. Allergy societies recommend against IgG tests for diagnosing food intolerances. Elevated IgG levels indicate contact with a food, not necessarily an intolerance. An IgE result does not provide this list either: Detecting sensitization “does not prove the clinical relevance of the food tested and should not alone lead to therapeutic elimination” (DGAKI and other specialist societies, 2021).
Do I need to continue eating gluten before a celiac disease test?
Yes. IQWiG states: “The test is only meaningful if sufficient gluten has been consumed beforehand.” (IQWiG, 2022) Both tests look for the reaction to gluten. If the trigger is absent for weeks, the result may appear unremarkable even when celiac disease is present. Anyone who is already eating gluten-free but still wants clarity should discuss the order of the tests with a doctor beforehand.
Is lactose intolerance an allergy?
No. “Lactose intolerance is not an allergy.” (IQWiG, 2024) According to the same source, people with a milk allergy react to even the smallest amounts of milk or dairy products, whereas people with lactose intolerance can tolerate certain amounts of lactose without symptoms. Around 5 to 15 percent of people in Europe cannot tolerate lactose (IQWiG, 2024). Because no antibody is involved, an antibody test is the wrong method here.
When should symptoms after eating be assessed immediately by a doctor?
If there is blood in the stool, unexplained weight loss, persistent fever, or symptoms that wake you from sleep at night. The same applies to reactions that begin within minutes and affect the skin, breathing, or circulation, such as swelling in the mouth and throat or shortness of breath. In these cases, you need a medical appointment, not a test, because an unremarkable result could delay necessary evaluation by months.
Next step
If you suspect an allergy
AllergoCheck measures specific IgE from capillary blood and thus covers the third of the three pathways. It does not provide a diagnosis and does not replace a consultation with a doctor. If your symptoms seem more consistent with lactose, you can make progress without this test.
View AllergoCheck The lactose pathway firstRead more
You might also be interested in this
If gluten is suspected and the order of the tests matters.
The lactose pathway, when the symptoms primarily affect the digestive tract.
For reference when the symptoms are less related to individual foods than to the gut itself.
Sources
- German Society for Allergology and Clinical Immunology (DGAKI), together with other professional societies, Worm M, Reese I, Ballmer-Weber B, Beyer K and others: Updated guideline on the management of IgE-mediated food allergies, AWMF registry number 061-031, Allergologie volume 44, issue 7, 2021 – register.awmf.org
- Institute for Quality and Efficiency in Health Care (IQWiG): Lactose intolerance, gesundheitsinformation.de, as of 06.11.2024 – gesundheitsinformation.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Celiac disease (gluten intolerance), gesundheitsinformation.de, as of 14.12.2022 – gesundheitsinformation.de
- Kleine-Tebbe J, Reese I, Ballmer-Weber BK, Beyer K, Erdmann S and others: No recommendation for IgG and IgG4 testing for foods. Position statement by DGAKI, ÄDA, GPA, ÖGAI, and SGAI following adoption of the task force report of the European Academy of Allergology and Clinical Immunology, Allergo Journal 2009 – gpau.de
The statements on sensitization, medical history, negative findings, the structure of diagnostics, and the prevalence figures of 3.7 percent in adults and 4.2 percent in children are taken from [1]. The information on milk sugar, distinguishing it from allergy, the breath test, and the proportions of 5 to 15 percent and 65 to over 90 percent are taken from [2]. The information on celiac disease, tissue transglutaminase, tissue sampling, gluten intake before testing, and the proportion of 1 to 2 percent are taken from [3]; the descriptions of wheat sensitivity are taken from the overview “Gluten and Wheat: Sensitivity, Allergy, or Intolerance?” by the same institute, as of 14.12.2022. The assessment of IgG and IgG4 testing is taken from [4]. Information on price, scope of testing, sample type, and laboratory comes from the mybody®x product page, accessed on 27.08.2026; processing times follow the central specification for blood tests. All sources were accessed and reviewed on 28.08.2026.
mybody®x Editorial & Expert Team
Laboratory diagnostics Allergology guideline development Nutritional science Blood analysis interpretation
This article was created by the editorial and expert team at mybody®x. The team combines laboratory diagnostics, nutritional science, and the interpretation of findings. Those who contribute to it are listed on the authors page.
Published on 21.07.2025 · Last updated on 27.08.2026
The content is intended for general information and does not replace medical advice, diagnosis, or treatment. The recommendations presented reflect the current state of the guidelines and institute publications cited; the decisive factors are the medical assessment in each individual case and the applicable guidelines.
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