What Is HAE?

Hereditary angioedema (HAE) is a rare disease that causes unpredictable attacks of swelling that typically occur in the face, throat, hands, feet, stomach (abdomen), and genitals. People with HAE experience recurrent episodes, or attacks, of swelling in the skin and/or mucous membranes. Depending on the severity of the disease, some people will have frequent attacks, while others may have few throughout the year.1 Physical exertion, stress, and trauma are commonly reported triggers of an HAE attack.2

During an attack, blood vessels release fluid, which causes swelling and pain. These attacks can be painful and affect one or more areas of the body at a time.

HAE management involves treating sudden attacks and if appropriate, preventing future attacks. You and your doctor should discuss if preventing attacks, or long-term prophylactic treatment, is right for you. Treating an attack as soon as possible after it starts may reduce the length of time it lasts.3

Learn more about HAE symptoms and HAE Attacks


Hereditary angioedema (HAE) is a rare disease affecting more than 1 in 67,000 people. Approximately 75% of patients have a family history of the disease, while almost 25% do not. Children have a 50% chance of inheriting HAE if one parent has it. HAE affects women and men equally and does not favor ethnicity.4

There are two main types of HAE—Type 1 and Type 2. People with these types of HAE have a mutated C1 esterase inhibitor (C1-INH) protein. C1-INH is responsible for controlling the activity of other proteins, such as kallikrein and factor XIIa. The different types of HAE are related to the amount or functionality of C1-INH.5

  • HAE Type 1: The body does not make enough C1-INH and it does not work properly. Type 1 is the most common, with 85% of people having this type.3
  • HAE Type 2: The body makes normal, or even higher, amounts of C1-INH, but it does not work properly. 15% of people have Type 2.3

Learn more about HAE Diagnosis and Treatment


[1] 2010 Lumry – The humanistic burden of HAE impact on HRQOL, productivity, and depressionREFERENCEvf1.15
[2] Zotter Z, Csuka D, Szabó E, et al. The influence of trigger factors on hereditary angioedema due to C1-inhibitor deficiency. Orphanet J Rare Dis. 2014;9:44.
[3] 2018 Maurer – The international WAO_EAACI guideline for the management of hereditary angioedema – the 2017 revision and updateREFERENCEvf1.14
[4] Bernstein JA. Severity of hereditary angioedema, prevalence, and diagnostic considerations. Am J Manag Care. 2018;24(14 Suppl):S292-S298.
[5] U.S. National Library of Medicine. C1 esterase inhibitor. National Institutes of Health. https://medlineplus.gov/ency/article/003353.htm. Updated October 2, 2019.