Understanding and Managing Hereditary Angioedema Triggers

Person holding throat

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Hereditary angioedema (HAE) is a rare genetic disorder that causes attacks of severe swelling in the skin, hands, feet, face, and airways. Although HAE attacks are often spontaneous, they can be caused by specific triggers. Understanding these triggers might help people to manage this condition.

This article will describe the symptoms of an HAE attack, common triggers, and how to identify and track potential triggers so you can manage HAE.

Symptoms of an HAE Attack

The predominant symptom of an HAE attack is recurrent episodes of swelling (edema) in the hands, feet, gastrointestinal tract, genitals, and throat. Attacks can vary in severity and usually last two to five days. The most common areas where symptoms occur include:

  • The skin: The hands and feet are particularly affected. The swelling can cause a lot of pain, limiting daily activities. 
  • The abdomen: Swelling can occur in the lining of the gastrointestinal walls leading to abdominal pain, nausea, diarrhea, and vomiting.
  • The throat: Swelling of the throat or voice box (larynx) can lead to pain, swallowing or speaking difficulties, and potential breathing difficulties.

HAE attacks do not respond to antihistamines or steroids as an allergic reaction would.

When To Call 911

Swelling in the throat and upper airways can be life-threatening, leading to suffocation. If symptoms of swelling in the throat occur, call 911 and seek medical attention immediately.

It may be possible to realize an attack is starting through early warning signs. Early warning signs of an HAE attack include:

  • Skin tingling
  • Extreme fatigue
  • Mood swings/bad temper/depression
  • Hoarse voice
  • Nonitchy rash
  • Heavy limbs

Trigger Factors in HAE

Although no one specific trigger causes an HAE attack, like with an allergy, several triggers are associated with the condition. The most-reported triggers include:

  • Hormonal changes: These include puberty, menstruation, pregnancy, hormone replacement therapy, menopause, breastfeeding, or contraceptive medication.
  • Stress: Emotional, mental, and happy stress (like celebrations) are known to trigger an attack of HAE.
  • Repetitive actions: Examples are typing, long periods of writing, hammering, or shoveling.
  • Trauma: Even a minor injury may be a trigger.
  • Medical/surgical procedures: These include dental surgery.
  • Infections: Examples include viral illnesses, colds, and flu.
  • Certain medications: These include ACE inhibitors and ibuprofen. ACE Inhibitors are taken to control high blood pressure. However, they are known to increase the frequency and severity of HAE attacks.

Managing HAE by Understanding Triggers

Early diagnosis and identifying trigger factors can help patients with HAE live a more manageable life.

The U.S. Hereditary Angioedema Association advises keeping a journal of when attacks occur. As part of the journal, include details such as:

  • The severity of the attack
  • How long the attack lasts for
  • Possible triggers
  • Treatment taken
  • Response to treatment
  • Any other details you think are critical about the attack

By recording everything in a journal, it can help to identify potential triggers as quickly as possible. 

Once triggers are identified, lifestyle changes can be made to help reduce the amount of HAE attacks. For example:

  • Avoid medication known to cause an HAE attack, such as ibuprofen or ACE inhibitors. Physicians can assist with prescribing alternatives where medication is required. 
  • Plan surgical/dental procedures with your healthcare team and take prophylactic (preventative) treatment before any medical procedures.
  • Consult your healthcare team to find an alternative, non-estrogen, birth control method.
  • Create a positive work-life balance to reduce excessive stress levels. Learn to integrate stress-reducing techniques into the day, such as relaxation time or meditation. 
  • Avoid repetitive activities or find ways to break up the movement if it cannot be avoided. 
  • Take time to plan celebrations so as not to become overwhelmed with happy stress.
  • Exclude any foods that regularly cause an HAE attack.
  • Get regular vaccinations, such as the flu vaccination, to help avoid illnesses.
  • Take short-term prophylactic medication when menstruating.

Identifying trigger factors is important as it is possible to avoid a proportion of HAE attacks through preventative measures.


Hereditary angioedema attacks are unpredictable, but people with the condition can sometimes associate them with various triggers. These include hormonal changes (especially menstruation), stress, infections, trauma, medical procedures, and certain medications.

By keeping a journal with details of attacks, you may be able to identify triggers and avoid them or take prophylactic medications when you may encounter the trigger.

A Word From Verywell

HAE attacks can be troubling and painful. Knowing what might trigger an attack can help you take better control of your condition. You may be able to take preventive medication and avoid an attack. Understanding your HAE triggers can help you lead a good quality of life. Prior planning and sensible precautions will help support you in living a full and active life.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. National Organization for Rare Diseases. Hereditary angioedema.

  2. US Hereditary Angioedema Association. HAE symptoms. attacks with swelling and pain.

  3. HAE UK. Hereditary angioedema. Patient information. 

  4. Zotter Z, Csuka D, Szabó E et al. The influence of trigger factors on hereditary angioedema due to C1-inhibitor deficiency. Orphanet J Rare Dis. 2014;9(1):44. doi:10.1186/1750-1172-9-44

  5. US Hereditary Angioedema Association. Triggers.

  6. Angioedema News. Hereditary angioedema triggers.

  7. Lumry W. Management and prevention of hereditary angioedema attacks. American Journal of Managed Care. 2013;19(7):S111-S118. 

By Helen Massy
Helen Massy, BSc, is a freelance medical and health writer with over a decade of experience working in the UK National Health Service as a physiotherapist and clinical specialist for respiratory disease.