Histamine is associated with common allergic responses and symptoms. Many of these are similar to those from a histamine intolerance.

While they may vary, some common reactions associated with this intolerance include:

headaches or migraines

nasal congestion or sinus issues

fatigue

hives

digestive issues

irregular menstrual cycle

nausea

vomiting

abdominal cramping

tissue swelling

high blood pressure

irregular heart rate

anxiety

difficulty regulating body temperature

dizziness

You naturally produce histamine along with the enzyme diamine oxidase (DAO). DAO is responsible for breaking down histamine that you take in from foods. If you develop a DAO deficiency and are unable to break down histamine, you could develop an intolerance.

Some reasons your DAO enzyme levels could be affected include:

medications that block DAO functions or prevent production

gastrointestinal disorders, such as leaky gut syndrome and inflammatory bowel disease

histamine-rich foods that cause DAO enzymes to function improperly

foods that block DAO enzymes or trigger histamine release

Bacterial overgrowth is another contributing factor for developing a histamine intolerance. Bacteria grows when food isn’t digested properly, causing histamine overproduction. Normal levels of DAO enzymes can’t break down the increased levels of histamine in your body, causing a reaction.