Abdominal attack An HAE attack that involves swelling in the intestinal wall. Symptoms include stomach pain, nausea, vomiting, and diarrhea. Acute treatment A type of “on-demand” treatment that’s given when an HAE attack starts. Everyone with HAE should have access to an acute treatment. Anti-inflammatory diet A diet that purportedly aims to reduce inflammation in the body. An anti-inflammatory diet generally emphasizes consuming whole, unprocessed foods and steering clear of inflammation-causing foods, such as refined carbs, soda, and red meat. Autosomal dominant A way in which a genetic trait or disorder is passed down through families. In an autosomal dominant disease, you only need to inherit one abnormal copy of a gene to be affected by the disorder. That means you have a fifty-fifty chance of inheriting a gene mutation if one parent has it. HAE is considered an autosomal dominant disorder. C1 inhibitor A protein that normally helps regulate swelling in the body. The genes that contribute to HAE often dysregulate this protein. If there isn’t enough working C1 inhibitor, your body can’t regulate inflammation and you’re at risk of an HAE attack. C4 protein A protein in your bloodstream that is often low in people with HAE. Doctors diagnose HAE and monitor the effectiveness of HAE treatments by measuring C4 levels in the blood. RELATED: What Is C1 Esterase Inhibitor, Human? Edema The accumulation of excess fluid in the body. F12 gene A gene that helps the body make a protein called coagulation factor 12, which plays a role in promoting inflammation and helping produce bradykinin. Researchers believe some cases of type 3 HAE are caused by mutations in the F12 gene. Hematologist A doctor who specializes in blood disorders and may be trained to help people with HAE. Hereditary Capable of being genetically inherited, or passed from parent to child. Kallikrein A protein found in the body. When kallikrein activity increases, too much bradykinin is produced, which causes a swelling attack. Laryngeal edema attack A type of HAE attack that happens when airways in your throat swell. If untreated, a laryngeal edema attack can be deadly. Prophylactic treatments Treatments that are taken to prevent symptoms. These therapies are used regularly to help ward off an HAE attack. SERPING1 gene A gene that tells the body how to make C1 inhibitor, which is important for controlling swelling. Changes in this gene can cause type 1 and type 2 HAE. Subcutaneous attacks A type of HAE attack that affects areas of the skin, typically on the face, hands, feet, or genitals. Type 1 HAE The most common type of HAE. In type 1, the body does not produce enough C1 inhibitor. Type 2 HAE With this type of HAE, there’s enough C1 inhibitor, but the protein doesn’t work like it should. Type 3 HAE An extremely rare form of HAE. With this type, C1 inhibitor levels and function are normal. Scientists believe some cases are causes by mutations in the F12 gene Triggers Something that sets off an HAE attack. Common triggers include stress, infections, trauma, a medical procedure, hormone changes, and certain drugs. Warning signs Some people with HAE experience warning signs before an attack starts. These may include mood changes, nausea, anxiety, extreme fatigue, and a rash or tingling feeling where the swelling occurs.