Hereditary angioedema (HAE) is a rare genetic condition that runs in families. It affects an estimated 1 in 50,000 to 150,000 people worldwide.

HAE causes “attacks,” or episodes of severe swelling. This swelling is most likely to affect your face, hands, feet, and genitals. It may also affect your gastrointestinal tract, airway, or other body parts, which can be life threatening.

Take a moment to learn more about this condition, including treatment options, triggers, and more.

There are two main treatment goals for HAE: to alleviate the symptoms of an attack and to reduce the frequency of those attacks.

Treating symptoms

To treat an acute attack of HAE symptoms, your doctor may prescribe one of the following medications:

  • C1 inhibitors, such as Berinert or Ruconest
  • ecallantide (Kalbitor)
  • icatibant (Firazyr)

These medications are sometimes called on-demand treatments. Your doctor can help you learn when and how to use them.

If you’re having trouble breathing during an attack, you should use your on-demand medication if it’s available. Then contact 911 or go to an emergency department for follow-up care.

To treat severe breathing difficulties, your doctor may need to perform a medical procedure such as an intubation or tracheotomy to open your airway.

Preventing symptoms

To help reduce the frequency of attacks, your doctor may prescribe one of the following medications:

  • C1 inhibitors, such as Cinryze or Haegarda
  • lanadelumab-flyo (Takhzyro)
  • androgen hormone therapy, such as danazol
  • in some cases, antifibrinolytic medication, such as epsilon aminocaproic acid (Amicar) or tranexamic acid (Lysteda, Cyklokapron)

Your doctor may also encourage you to make lifestyle changes to limit your exposure to certain triggers. For example, reducing emotional stress may help prevent episodes of symptoms.

Symptoms of HAE typically first appear in childhood or adolescence.

During an attack, you may experience any of the following symptoms:

  • swelling of your face, hands, feet, genitals, or other body parts
  • abdominal pain, nausea, vomiting, or diarrhea due to gastrointestinal tract swelling
  • difficulty swallowing, speaking, or breathing if swelling affects your airway

About one-third of people with HAE develop a rash. It’s not itchy or painful.

If you develop swelling in your airway, it may cause potentially life threatening breathing problems. It’s important to get treatment and seek emergency services right away.

There are three main types of HAE. Each type is caused by different genetic mutations.

All three genetic mutations cause your body to produce too much bradykinin, a protein fragment that helps drive inflammation.

Bradykinin triggers changes in your blood vessel walls that cause them to become more permeable, or leaky.

This allows excess fluid to leak from your blood vessels into other tissues, which results in swelling.

Type 1

Type 1 HAE makes up about 85 percent of all cases of HAE.

It’s caused by mutations in the SERPING1 gene. This gene tells your body how to produce C1 inhibitor, a protein that limits bradykinin production.

If you have genetic mutations that cause type 1 HAE, your body won’t produce enough C1 inhibitor.

Type 2

Type 2 HAE accounts for about 15 percent of all cases of HAE.

Similar to type 1, it’s caused by mutations in the SERPING1 gene.

If you have genetic mutations that cause type 2 HAE, your body will produce C1 inhibitor that doesn’t work properly.

Type 3

Type 3 HAE is very rare. The exact cause isn’t always known, but some cases of it result from mutations in the F12 gene.

This gene gives your body instructions for making coagulating factor XI, a protein that plays a part in the production of bradykinin.

If you inherit genetic mutations that cause type 3 HAE, your body will produce overactive coagulating factor XII.

If you have HAE, you may find that certain triggers cause episodes of symptoms to develop or worsen.

Common triggers include:

  • physical injuries
  • dental procedures or surgery
  • viral infections
  • emotional stress

You may also experience episodes of symptoms with no known trigger.

The average life expectancy of people with HAE is the same as the general population, according to recent research.

HAE can cause life threatening breathing difficulties if you experience swelling in your airways. When that happens, it’s essential to get treatment right away.

If you develop breathing difficulties during an episode of symptoms, take on-demand medication if you have it on hand. Then call 911 or go right to a an emergency department.

Some of the symptoms of HAE are similar to those of other conditions. For example, allergic reactions can also cause swelling, gastrointestinal symptoms, and breathing difficulties.

To diagnose the cause of your symptoms, your doctor will first conduct a thorough clinical evaluation and ask you about your personal and family medical history.

If your doctor suspects that your symptoms are caused by HAE, they’ll order blood tests to check the level of certain proteins in your blood. They may also order genetic testing to check for certain genetic mutations.

HAE is caused by genetic mutations that may be passed from parent to child. This means that the condition tends to run in families.

However, spontaneous mutations can cause the disease to develop in people with no family history of the disease.

If you have HAE, limiting your exposure to triggers may help prevent symptom attacks. Certain lifestyle changes may also help you manage the physical, emotional, and social effects of the condition.

For example, it might help to:

  • Prepare for dental work or surgery. If you have dental work or other medical procedures scheduled, let your doctor know. They may prescribe medication to lower your risk of a symptom attack.
  • Plan travel carefully. Before you travel for work or pleasure, learn where and how you can get help in the case of an emergency. Consider avoiding trips to areas where medical care is hard to access.
  • Take steps to limit and relieve emotional stress. Try not to take on more obligations at work or home than you can comfortably manage. Strive to make time for stress-relieving activities, such as yoga, reading, or quality time with loved ones.
  • Meet with a mental health specialist if needed. Living with a rare condition like HAE can have an impact on your mental health. A mental health specialist can help you develop coping strategies and a treatment plan if needed.
  • Join a support group. Connecting with other people who live with HAE may give you a sense of social and emotional support. You may also be able to share practical tips with each other for managing HAE.

If you’re finding it difficult to manage the physical, emotional, or social effects of HAE, let your doctor or other members of your health team know.

They may adjust your treatment plan, offer tips for managing the condition, or refer you to other sources of support in your community.

Without treatment, HAE tends to cause frequent attacks of symptoms. Getting treatment may help relieve acute symptoms and reduce the frequency of attacks. This can improve your physical and mental health, while allowing you to lead a full life with HAE.

Talk to your doctor or other members of your health team to learn more about the potential treatment options for HAE.