Hereditary Angioedema - C1 Inhibitor Deficiency

Welcome to the United States Hereditary Angioedema Association’s website. We are a non-profit patient advocacy organization dedicated to expediting US approval of safer and more effective HAE therapies. In addition, we provide a wide range of services that include clinical trial placement, physician referrals, education and individualized patient case management.

About HAE

Hereditary Angioedema (HAE) is a rare disorder that results from a genetic deficiency of the blood-based protein C1 inhibitor. HAE patients experience attacks of edema (swelling) in the hands, face, feet, abdomen, and/or throat (airway).

Swelling that involves the throat can close the airway and cause death by suffocation. Abdominal attacks often result in severe pain and intense vomiting serious enough to require hospitalization for pain management and IV fluids.

Diagnosis & Treatment

Anyone with a history of swelling attacks should obtain a thorough work-up from a specialist. In our experience, specialists in Allergy/Immunology have the background and training necessary to diagnose the cause of chronic swelling. Because HAE is very rare, most patients with edema symptoms will receive a diagnosis that points to other conditions. If you have trouble locating a physician knowledgable about HAE, click here to access our physician referral program.

As noted on this website’s Angioedema Table, there are many possible causes for persistent swelling. It is important to get a correct diagnosis because treatments vary depending on what is causing the edema. Our FAQ provides detailed information on HAE symptoms, diagnosis, and treatments.

New Treatment Options

Currently there are several ongoing clinical trials which offer promising new treatments for acute HAE attacks. Contact Clinical Programs Director, Donna Davis or fill out an interest form for more information on these trials and learn about the new treatments that will revolutionize HAE patients' lives in the near future.

We hope you enjoy exploring our website and learning about HAE and the US HAE Association’s activities and programs.


Disclaimer: The information, including opinions and recommendations, contained in this website is for educational purposes only. Such information is not intended to be a substitute for professional medical advice, diagnosis or treatment. No one should act upon any information provided in this website without first seeking medical advice from a qualified medical physician. Information derived from the internet or emails, no matter how accurate or relevant are no substitute for competent medical care.