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Hereditary Angioedema (HAE)

What Is Hereditary Angioedema?

It’s a rare genetic condition that causes swelling under the skin. It can happen in different parts of your body.

You are born with hereditary angioedema (HAE). Although you’ll always have it, treatment helps you manage it.

There have been big improvements in therapies, and researchers continue to look for new solutions.

Symptoms usually show up in childhood and get worse during the teen years. Many people don't know HAE is causing their swelling until they're adults.

With this disease, a certain protein in your body is not in balance. This causes tiny blood vessels to push fluid into nearby areas of your body. That leads to sudden swelling.

Where you have it, how often the bouts happen, and how strong they are is different for everyone. The attacks can come and go as well as move to different spots during the same bout.

Your throat can swell. That can cut off your airway, which is life-threatening. So if you know you have HAE and you feel any change like that, call 911 right away.

Without treatment, you can have attacks as often as every 1 to 2 weeks, and they can be hard to manage.


A problem with a gene that controls a blood protein called C1 inhibitor often causes HAE. In most cases, you don’t have enough of this protein. In others, you have normal levels but it doesn't work right.

If one of your parents has HAE, you have a 50% chance of having it, too. But sometimes the gene change happens for unknown reasons. If you have the broken gene, you can pass it on to your children.