DAO Test — Diagnose Histamine Intolerance
Histamine intolerance occurs when the body has a reduced ability to break down histamine, a substance naturally found in both foods and the body. When histamine builds up, it can trigger symptoms that closely resemble allergies without a true allergic reaction. The DAO test measures the level of the enzyme diamine oxidase, which is essential for breaking down histamine in the digestive tract. Because histamine intolerance symptoms overlap with conditions like IBS, allergies, or chronic fatigue, it is often misdiagnosed.
Why Test DAO Test?
This test is especially relevant if you experience unexplained symptoms after eating, migraines or chronic headaches, IBS-like symptoms, fibromyalgia or chronic fatigue, or sensitivity to foods like aged cheese, wine, tuna, sausage, or fermented products.
What Do High DAO Test Levels Mean?
A DAO level above 10 U/mL indicates normal enzyme activity, meaning histamine is likely broken down properly. A high DAO level is generally not concerning and suggests adequate enzyme capacity.
What Do Low DAO Test Levels Mean?
A DAO level of 3-10 U/mL indicates moderately reduced activity with possible histamine intolerance. A level below 3 U/mL indicates severely reduced DAO activity and a strong indication of histamine intolerance. Dietary adjustments to reduce high-histamine foods may provide significant relief.
Symptoms to Watch For
- Headaches or migraines after eating certain foods
- Itching, skin rashes, or hives
- Stomach upset, bloating, or diarrhoea
- Palpitations or racing heart
- Nasal congestion or runny nose
- Asthma-like breathing difficulties
- Swelling of face or extremities
Who Should Get Tested?
- People with unexplained allergy-like symptoms
- Those with chronic headaches or migraines triggered by food
- Individuals with IBS-like symptoms or chronic digestive issues
- Anyone sensitive to aged cheese, wine, cured meats, or fermented foods
How to Prepare for Your Test
Certain medications can temporarily affect DAO levels, including antibiotics, acid blockers, and antihypertensives. Avoid testing during pregnancy or after recent allergic shock. Discuss with your doctor if you take medications that may affect results. Bring valid ID to your appointment.
Frequently Asked Questions
Is histamine intolerance the same as a food allergy?
How can I manage histamine intolerance?
How long does it take to get results?
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.