While there’s often no clear cause of hereditary angioedema (HAE) attacks, physical activity, trauma, stress, and certain medications can all be triggers.

It’s not always possible to avoid HAE triggers, but understanding and anticipating them can help you take control of your HAE.

Different people may experience HAE attacks as a result of different triggers. Below, we list some of the most common triggers for HAE attacks.

Physical activities

Physical activities that create repeated pressure can trigger HAE attacks. These triggers include foot-swelling from standing in one place for a long time and hand-swelling from gripping a tool.

The attack usually occurs in the same part of your body as the triggering event.

Other repetitive activities that may cause HAE flare-ups include:

  • typing
  • mowing the lawn
  • shoveling
  • hammering

Some patients may also have an attack with excessive exposure to sun, cold, or water. Other environmental factors that can cause an attack include insect bites or stings, pollen, animal dander, and exposure to latex.

Stress and trauma

Various physical and emotional traumas can trigger attacks anywhere in the body. Dental work is a special concern because a flare-up around the face or throat could lead to airway swelling.

Trauma-related triggering events can include:

  • emotional stress
  • fatigue
  • infections
  • surgery
  • dental work
  • tongue or facial piercing
  • illness

Hormonal changes

Hormone fluctuations may lead to HAE attacks. Some women report an increase in attacks during their menstrual periods.

Pregnancy can also affect HAE flare-ups. Some people have more attacks during pregnancy, but others may notice fewer attacks.

Hormone replacement therapy or estrogen-based birth control can make HAE attacks more frequent or severe.


Blood pressure medications that contain ACE inhibitors can worsen HAE attacks. If you have HAE and need blood pressure medication, your doctor will work with you to prescribe an alternative that doesn’t contain an ACE inhibitor.

Before starting any new medication, it’s best to discuss it with an HAE specialist.

Certain medications may also trigger an attack of HAE. Some of the more common medications include:

  • aspirin
  • nonsteroidal anti-inflammatory drugs (NSAIDs)
  • antibiotics
  • blood pressure medications, especially
    ACE inhibitors
  • oral contraceptive agents
  • blood transfusions or medications that have been derived from serum


Some people with HAE are sensitive to certain foods, such as:

  • seafood
  • shellfish
  • nuts
  • eggs
  • milk

Once you understand what triggers your HAE, do your best to avoid those events.

For example, vaccination for influenza prevents airway infections that may lead to an attack.

Practicing good dental hygiene habits every day can reduce your need for dental surgery.

If you’re stressed or fatigued, talk with your doctor about lifestyle changes you can make.

If you know you’ll need surgery or extensive dental work you may wish to undergo short-term treatment with preventive medication. There are a couple of options for preventive treatment.

One is taking a high dose of androgen therapy before and after surgery. Another option is taking a concentrated C1 inhibitor in the hours right before surgery.

Even if you undergo preventive treatment, “breakthrough” attacks are still possible. It’s always important to have on-demand medication available and a plan for how to administer it.

You may find it helpful to keep a paper or electronic log of every attack. Logging your attacks will help you, and your doctor monitors your treatment plan and understand what triggers your attacks.

The log should contain a description of your attack, what you did for treatment, and how you responded. Your doctor can help you choose a recording system that works best for you.

By anticipating and being prepared to treat HAE flare-ups, you can manage your HAE and live a full and active life.