C₁ inhibitor (C₁-INH) mainly controls inflammation. When there’s a problem with the C₁ inhibitor, the body can’t control inflammation very well and sometimes leads to HAE.
- Type I HAE: The body doesn’t make enough C₁ inhibitor. This type is the most common.
- Type II HAE: There are sufficient amounts of C₁ inhibitor, but it doesn’t work as well as it should.
- Type III HAE: More common in women and can become worse with pregnancy or birth control medicines. The C₁ inhibitor is normal. The cause is unknown.
