Checking Your Symptoms

Hereditary angioedema (HAE) may mimic other types of medical conditions. For example, it may be mistaken for allergies or stomach problems. However, there are clues that help physicians identify HAE and distinguish it from other medical problems.

How do you know if you have HAE? Use these tools to check your symptoms:

Eight questions

The A to G of HAE

Again and again

HAE attacks tend to occur again and again. These recurrent attacks may have begun in childhood and may have worsened over the years.3

Body part

HAE can occur in different body parts during different attacks. Additionally, swelling can move from one site to another. For example, a facial attack can move to other sites, such as the throat. HAE attacks often affect only one side of the body. Attacks usually occur at a single site but simultaneous edema at other sites is not uncommon.1

The most common sites for attacks are:3

  • Extremities (hands, feet, arms, legs)
  • Intestines (abdomen)
  • Face
  • Genitals
  • Larynx, or voice box

C1 esterase inhibitor

C1 esterase inhibitor is a protein produced in the complement system of the “innate immune system.” HAE can occur if your body produces either too little C1 esterase inhibitor or C1 esterase inhibitor that does not function properly. Blood tests can be done to check protein levels.


Allergic reactions to foods, drugs, or insect bites tend to respond quickly to medications, such as epinephrine, antihistamines, and corticosteroids.HAE attacks generally do not respond to such medications. Because HAE attacks spontaneously improve over time, it could appear that anti-allergy drugs are effective. In reality, however, HAE attacks do not respond dramatically to anti-allergy treatments.


The location of HAE attacks can vary, but all HAE attacks involve edema. Edema is an abnormal accumulation of fluid beneath the skin and in cavities of the body, which manifests as swelling. HAE involves a form of edema called angioedema, which is considered a “non-pitting” edema because if you press on the area the skin bounces back and does not leave an indentation or pit.

Family history

It is possible to be the first person in your family to develop the abnormal gene that causes HAE. In most cases, however, others will have had unrecognized HAE attacks and not been formally diagnosed.

Even if no one in your family has been diagnosed with HAE, speak with family members (parents, aunts, uncles, etc.) to see if they have had swelling episodes that sound like they might be related to HAE.

Gastrointestinal attacks

Gastrointestinal attacks of HAE can be characterized by excruciating abdominal pain, nausea and other GI symptoms, and can be easily misdiagnosed in patients who have not yet been diagnosed with HAE. According to HAEA, approximately one third of patients with undiagnosed HAE undergo unnecessary abdominal surgery because attacks mimic a surgical emergency.

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Answering 7 simple questions may help you to tell the difference between HAE and other conditions

Answer these questions to see if your symptoms fit the profile of HAE:

  • Have you had unexplained attacks of swelling in your hands, feet, arms, legs, face, throat, or genitals?
  • Have these swelling attacks started or occurred at just one site of your body—for example, just your left hand or just your right foot?
  • Have you had unexplained attacks of abdominal pain?
  • Have these attacks of swelling or abdominal pain occurred more than once?
  • Has anyone in your family had similar episodes of swelling or abdominal pain?
  • Do you sometimes feel warning signs (such as fatigue, tingling, nausea, or flu-like symptoms) that occur — minutes, hours, or even days before full onset of an attack?
  • Have medications, such as antihistamines, epinephrine or steroid shots, provided little relief, if any?

If you answered “yes” to all or nearly all of the 7 questions, your symptoms may suggest HAE. You should discuss your medical history with a physician who understands the disease and how to treat it. A blood test can help to confirm the diagnosis.

If you have trouble locating a specialist, you may want to contact the U.S. Hereditary Angioedema Association. This organization maintains a robust list of doctors across the country who treat people living with hereditary angioedema.

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