Warning Signs


HAE crises are often unpredictable; some potential triggers have been identified :

  • Emotional or psychological stress.
  • Physical trauma (eg, injury, surgery, childbirth, dental intervention).
  • Physiological trauma (eg, viral or bacterial infection).
  • Surgery, anesthesia.
  • Hormone levels fluctuation (menstruation, oral contraceptives).


Be alert and notice events, drug changes or any situation that may precede or trigger an HAE attack :

  • Keep a record of your attacks that indicates the location and frequency of your crisis, including their duration.
  • Be sensitive to patterns or scenarios that may occur (such as emotional triggers, medication change and if you are a young woman, the timing of your oedemas versus your menstrual cycle).
  • Write down any physical warning signs or symptoms (such as tingling, tiredness, nausea, flu-like symptoms, feeling hot on the skin, or rash) to be a precursor of a crisis. Being able to quickly identify an upcoming crisis can lead to early treatment and can help alleviate a large-scale crisis.

Notice if certain medications or oral contraceptives influence your symptoms.

How to avoid triggering a crisis

Avoid situations that can cause a crisis and discuss with your doctor before exposing you to known triggers.

  • For women, do not use contraceptives containing estrogen.
  • If emotional stress is a trigger, avoid emotionally charged situations. Ask for help and support and use strategies to handle the situation. AOH Quebec is a tool you can use for guidance.
  • Plan your schedule by knowing the situations that can trigger an HAE crisis and try to avoid the most potential triggers on a daily basis and be prepared for a crisis.

How to prepare for a crisis

For many patients with HAE it is impossible to prevent an attack. In this case, the best thing to do is being prepared to deal with it.

  • Inform your family, friends and co-workers of your condition.
  • Before traveling outside your region, locate a treatment center near your destination.
  • Prior to a dental procedure, discuss your medical condition and options with your HAE specialist and your dentist.
  • Wear your medical bracelet, a patient identification card in case of emergency that indicates your medical needs in case you could not verbally communicate your needs.