What is HAE?
Hereditary angioedema (HAE)
is a rare genetic disease
HAE can cause repeated attacks of swelling that can be painful, unpredictable, and debilitating. They can be different for each individual and can also change over time. These attacks can occur in different parts of the body, including the face, hands, feet, and even the throat, which can become life-threatening. HAE is called "hereditary" because it usually runs in families.

Type I
- Low level of C1-INH
- C1-INH functions normally
- Most common (~85% of people with HAE)
Type II
- Normal level of C1-INH
- C1-INH doesn't function normally
- Less common (~15% of people with HAE)
Can HAE be misdiagnosed?
Because HAE symptoms can look very similar to the symptoms of other, more common conditions, it can be easy to misdiagnose. In a 2010 survey of 313 people with HAE, up to 65% of the participants had been misdiagnosed with another condition prior to receiving their HAE diagnosis:
- Most commonly, skin attacks were mistaken for other skin conditions, like contact dermatitis, which can cause the skin to become irritated and swollen
- Abdominal attacks were also confused with appendicitis or irritable bowel syndrome
What can getting misdiagnosed with another condition mean?
- It can take longer to get an accurate HAE diagnosis
- People who are undiagnosed are at greater risk of receiving the wrong treatment
- In an emergency situation, like an HAE attack affecting the airway, getting the wrong treatment has the potential to be life-threatening