No home test can diagnose celiac disease. The kits sold in pharmacies and online do not provide an accurate medical diagnosis, and national medical guidelines do not recognize them (Coeliac UK). The only reliable route is a blood test and, in many cases, a biopsy of the small intestine.
There is something useful you can do at home: spot the signs that deserve a doctor’s visit and avoid the mistake that ruins the result, which is cutting out gluten too early. To see why that gluten matters so much, read what is gluten.
Short answer: no home test can confirm celiac disease. Pharmacy kits do not give an accurate diagnosis, and hair analysis or IgG tests are not reliable. Diagnosis takes a blood test and often a biopsy, and you must keep eating gluten until both are done: at least 3 g a day for six weeks (Coeliac UK).
Is there a home test to know if you are celiac?
No. Coeliac UK, the UK’s celiac charity, is clear: home testing kits “do not provide an accurate medical diagnosis” and are “not recognised by national medical guidelines”. Whatever the result, its advice is to talk to your doctor about your symptoms.
People who look for a home test for gluten intolerance want a fast answer without leaving the house. A fast, wrong answer can delay a diagnosis.
Pharmacy gluten tests: what they are and why they are not enough
Celiac and gluten intolerance tests are sold in pharmacies, drugstores and online. If you buy one, treat it as a data point to bring to your doctor.
A pharmacy gluten test should not lead you to cut out gluten on your own either: the NHS says not to start a gluten-free diet until a specialist confirms the diagnosis, even if a blood test is positive.
Hair analysis, IgG tests and others that do not diagnose
Coeliac UK lists alternative tests, marketed to detect allergies or intolerances, that are not used for celiac disease: applied kinesiology, hair analysis, IgG gliadin antibody tests, leukocytotoxic tests and Vega testing. Its conclusion: they are not regarded as accurate or reliable, and they do not diagnose celiac disease.
How to know if you are celiac or gluten intolerant: the signs that count
Symptoms give clues and medical tests confirm. Telling whether you are gluten intolerant or celiac takes those tests. About 1% of people worldwide have celiac disease (NIDDK) and, in Spain, it is estimated to affect 1 in 71 children and 1 in 357 adults (Spanish Ministry of Health).
Because symptoms come and go, and sometimes never appear, many cases go unnoticed: FACE, the Spanish federation of celiac associations, estimates that 75% to 80% may remain undiagnosed.
The most common signs in adults, according to the NHS and NIDDK:
- Repeated diarrhea or loose stools.
- Bloating, gas and abdominal pain.
- Persistent tiredness, sometimes from anemia.
- Unexplained weight loss.
- An itchy, blistering rash (dermatitis herpetiformis).
- Tingling or numbness in the hands and feet.
Celiac disease symptoms in children include slowed growth, short height, delayed puberty and damage to the enamel of permanent teeth, according to NIDDK.
Stools and celiac disease: what to look for
NIDDK describes celiac stools as loose, greasy, bulky and bad-smelling. The NHS adds that they can be frothy and hard to flush. This is steatorrhea, and it happens when the intestine does not absorb fat well.
If you notice it repeatedly, book an appointment: it is a reason to see a doctor.
Celiacs with few symptoms or none
The NHS puts it this way: symptoms can range from mild to severe, and treatment is recommended even when they are mild or non-existent, because complications can still occur. Having a close relative with celiac disease makes it more likely (NIDDK). In that case, ask your doctor about a check-up even if you notice nothing.
Symptoms of non-celiac gluten sensitivity
Some people have similar discomfort, such as abdominal pain and tiredness, without having celiac disease. NIDDK explains that gluten sensitivity, unlike celiac disease, does not damage the small intestine. Wheat allergy is a different matter: it causes symptoms such as itchy eyes or trouble breathing.
Finding out whether you are gluten intolerant starts by ruling out what can be measured: celiac disease and wheat allergy. Your doctor does that.
What if I stop eating gluten for a few weeks to see how I feel?
It is the most popular home test and the one that goes worst. If you remove gluten before the blood test, FACE warns that the tests can give false negatives. The NHS agrees: avoiding gluten “could lead to an inaccurate result”.
Coeliac UK recommends including at least 3 g of gluten a day, preferably 6 g, for at least six weeks before testing and throughout the diagnosis process (diagnosis guide). For reference, 3 g of gluten is about 60 g of wheat bread (one and a half to two slices, or a medium roll) or 90 g of cooked pasta.
If you are unsure what contains gluten, our guide on does bread have gluten? covers one of the most common cases.
The first symptoms after stopping gluten are usually improvements: NIDDK says symptoms typically improve and may go away on a gluten-free diet. That improvement does not prove you are celiac, and it leaves you unable to confirm it later without eating gluten again.
If you have already been off gluten for a while, do not restart it on your own. Coeliac UK recommends discussing with your doctor how to reintroduce it and how to manage symptoms in the meantime.
Medical tests to diagnose celiac disease
These are the tests to know if you are celiac that medicine recognizes. Diagnosis starts with a blood test that looks for antibodies, and a biopsy of the small intestine can confirm it (NHS).
Blood test: the first celiac test
Serology looks in the blood for the antibodies typical of the disease, including tissue transglutaminase antibodies (FACE). It is the first of the celiac tests your family doctor orders. If antibodies appear, the NHS explains that the doctor refers you to a specialist.
The same rule applies here: for this celiac test to be reliable, you need to be eating gluten.
Biopsy and the Marsh classification
A biopsy takes a sample of the duodenum to look for damage. FACE describes it as the definitive test. The pathologist grades the damage with the Marsh-Oberhuber classification, which runs from type 0 (normal mucosa) to type 3 (villous atrophy, in three subgrades: a, b and c).
On grades of celiac disease, FACE sums it up: celiac disease has no grades, you either have it or you do not. Marsh measures the damage to the intestine in the biopsy.
HLA and celiac disease: genetic testing rules it out
Almost everyone with celiac disease carries the HLA-DQ2 or DQ8 variants. But about 30% of the population has them and only about 3% of those people develop the disease (NIDDK). That is why HLA testing is used to rule out celiac disease: without those variants, it is very unlikely. A positive result does not diagnose.
According to FACE, the 2026 update of the Spanish Ministry of Health protocol removes genetic testing from the initial diagnosis and keeps it for specific clinical situations.
Which test does what
| Test | Does it diagnose celiac disease? | What you should know |
|---|---|---|
| Pharmacy home kit | No | It does not give an accurate diagnosis. Discuss the result with your doctor. |
| Hair analysis, IgG tests, kinesiology | No | They are not regarded as accurate or reliable. |
| Stopping gluten for a few weeks | No | It can cause false negatives in later tests. |
| Antibody blood test | First step | Your doctor orders it. You must keep eating gluten. |
| Small intestine biopsy | Yes | Considered the definitive test by FACE. In children with very high antibodies it can be avoided. |
| Genetic test (HLA) | No | It only serves to rule the disease out. |
Celiac disease: diagnosis step by step
How celiac disease is diagnosed in practice:
- See your family doctor and describe your symptoms and any celiac relatives.
- Keep eating gluten until all the tests are finished.
- Take the blood test that looks for antibodies.
- If antibodies show up, your doctor refers you to a specialist, who decides whether a biopsy is needed.
- Once the diagnosis is confirmed, start the gluten-free diet.
Diagnosis is changing. The update of the Spanish Ministry of Health protocol, published on 15 July 2026 according to FACE, adopts the ESPGHAN criteria for diagnosing children without a biopsy and gathers the evidence on their possible use in adults with very high antibody levels. Ask your specialist whether your case fits.
Intolerance, sensitivity, allergy or celiac disease
When someone says “I am gluten intolerant” they can mean three different things, according to NIDDK:
- Celiac disease: a chronic digestive and immune disorder that damages the small intestine.
- Non-celiac gluten sensitivity: similar symptoms, without damage to the small intestine.
- Wheat allergy: an immune reaction to wheat, with symptoms such as itchy eyes or trouble breathing.
After the diagnosis: eating gluten free without the hassle
Today the only treatment is a strict, lifelong gluten-free diet (FACE). The first weeks are hard, especially when eating out.
At Gato Blanco the whole menu is gluten free, from the bread to the dessert, and the kitchen is certified by ACECOVA, the Celiac Association of the Valencian Community. We are a gluten free restaurant in Valencia, in La Zaidía, and you can choose any dish from the gluten free menu without asking what is in it. If you have another allergy, ask us: the kitchen works with dairy, eggs and nuts. To eat out with confidence, see our restaurants for celiacs in Valencia.
To build confidence, these guides save you doubts:
- Gluten free beer: brands, regulations and where to have it in Valencia.
- Does rice have gluten?: why it does not, and where the cross-contact risk is.
- Gluten free breakfast: 10 ideas with step-by-step recipes.
Want to try it? Book a table or write to us from the contact page. And for more reading, browse the Gato Blanco blog.
Frequently asked questions
Is there a celiac test I can do at home?
Kits are sold in pharmacies and online, but they do not provide an accurate medical diagnosis and national medical guidelines do not recognize them, according to Coeliac UK. If you take one, discuss the result with your doctor and keep eating gluten. Diagnosis takes a blood test and, in many cases, a biopsy.
What do experts say about pharmacy gluten intolerance tests?
Coeliac UK warns that they do not give an accurate diagnosis. Hair analysis, IgG tests and kinesiology are not useful either, and they are not regarded as accurate or reliable. Whatever the result, talk to your doctor before changing your diet.
How much gluten do I need to eat before the tests?
Coeliac UK recommends at least 3 g of gluten a day, preferably 6 g, for at least six weeks before testing. For reference, 3 g of gluten is about 60 g of wheat bread (one and a half to two slices) or 90 g of cooked pasta. Confirm the details with your doctor.
Can celiac disease be diagnosed without a biopsy?
In children, sometimes: ESPGHAN set criteria for it, and the 2026 update of the Spanish Ministry of Health protocol includes them, according to FACE. For adults, the evidence on very high antibody levels is still being assessed. The decision always belongs to your specialist.
Does a positive genetic test mean I am celiac?
No. According to NIDDK, about 30% of people carry the HLA-DQ2 or DQ8 gene variants and only about 3% of them develop celiac disease. A negative result makes the disease very unlikely. That is why genetic testing is used to rule out celiac disease, not to confirm it.
How do I know if I am gluten intolerant and not celiac?
With medical help. Celiac disease and wheat allergy are ruled out first. Gluten sensitivity causes discomfort such as abdominal pain and tiredness but, unlike celiac disease, it does not damage the small intestine (NIDDK). Do not start a gluten-free diet before those tests.
This article is for information only and does not replace a doctor’s advice. If you suspect you may be celiac, book an appointment before changing your diet.
