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Managing hereditary angioedema (HAE)

Managing hereditary angioedema (HAE)

Recognising the signs of an HAE attack

Attacks of HAE can occur suddenly and without warning. However, many people with HAE notice early stage symptoms that warn them that an attack is about to happen. These are called the prodrome, or prodromal symptoms.

Some common prodromal symptoms include:
Sudden mood changes
Extreme fatigue
A tingling sensation of the skin where the swelling will begin

Some people notice these symptoms minutes or hours before an attack, while others can feel them a whole day or two before a full attack begins. Learning to recognise early stage symptoms of an attack will help you to stay in better control of your condition, as well as being aware of signs that it may be developing into a more serious attack.

Should your symptoms prevent you from completing everyday activities such as tasks for work, socialising or house chores then you should have a treatment plan agreed with your immunology team (see Working with your healthcare team).

Identifying serious attacks

Some HAE attacks can be extremely serious.

The following symptoms can indicate a situation that may require immediate medical atttention:

Throat swelling that blocks the airway, prevents normal breathing and is therefore life-threatening; such attacks require immediate emergency care. Some of the symptoms of throat swelling may include a hoarse voice or laryngitis, difficulty in swallowing, throat tightness, and other voice changes. This type of attack should be treated at the nearest A&E department.

Intestinal swelling which can cause intense abdominal pain that can progress to vomiting and diarrhoea; intestinal swelling can be mistaken for an abdominal disorder, such as appendicitis, as the symptoms can be similar, which makes diagnosis difficult.

Call 999 immediately if you notice any of the following symptoms

  • Hoarse voice or laryngitis
  • Whistling or wheezing when breathing
  • Shortness of breath
  • Swollen tongue
  • Lip or facial swelling
  • Throat swelling

Identifying potential triggers

Even though HAE attacks are often unpredictable, some are triggered by stress, hormones, infections and even medications. It’s important to become familiar with your HAE triggers so you can be prepared should an attack occur.

Following these four steps should help you to stay in control where possible:

Recognise your triggers

Recognise your triggers

Be aware of events, changes in medications, or situations that may precede or trigger an HAE attack

Avoid triggers

Avoid triggers

Avoid situations that may trigger an attack. Talk to your doctor before exposure to any known triggers, such as dental work, surgery or giving birth.

Avoid trigger medications

Avoid trigger medications

Pay careful attention to patterns of attacks and identify any medications (such as oestrogen contraceptives, hormone replacement therapy, or ACE inhibitors (for high blood pressure)) that may contribute to the onset of your HAE attacks.

Be prepared

Be prepared

For some people with HAE, an attack cannot be avoided. In that case, the best policy is to be prepared (see below for further advice).

Preparing for an attack

If your attacks have no obvious trigger, the following steps can be taken to prepare for your attacks whenever they may happen:

  • Educate family, friends and co-workers about your condition.
  • Before you travel, locate the nearest A&E department. Discuss your medical condition and dental work options with both your HAE specialist and your dentist, especially if you are considering extractions or other dental work.
  • Keep a diagnosis letter with you at all times – Download sample diagnosis letters here.

Working with your healthcare team

Many people living with HAE find that it helps to work with their healthcare team to manage the condition. One of the strategies to help you and your healthcare team manage your HAE effectively is to make sure you understand what you can expect from each other.

Some simple suggestions for the responsibilities of each party are as follows:

What you can expect from your healthcare team

Maintain a detailed history of HAE attacks:

  • Trigger
  • Location
  • Frequency
  • Duration

Be informed and mindful of health conditions.

Know about other family members with HAE.

Have an agreement on pain medication.

Provide a letter of diagnosis to be shown to the hospital A&E department if required.

Download sample diagnosis letters here.

What the person with HAE should do

Keep a detailed record of HAE attacks:

  • Trigger
  • Location
  • Frequency
  • Duration

Tell your doctor about any changes in medication or any planned surgeries or dental procedures.

Make healthy lifestyle and food choices.

Be aware of mood changes.

Know your prodromal symptoms (early HAE attack warning signs).

Get to a hospital when necessary.

Have someone who will watch out for you.

Remain hydrated to replace fluids lost to swelling.

During painful attacks, take pain control medications early.

Notify your doctors, dentists and your child’s school, e.g. by providing a letter of diagnosis.

Download sample diagnosis letters here.

Preventing HAE attacks

If you believe you might have HAE, the first step is to visit your GP who will be able to assess your symptoms, conduct some investigations and decide whether you need to be referred to an immune system specialist, called an immunologist, who can further help with diagnosis and treatment.

Preventative therapy

Preventative therapy

Your doctor may prescribe certain medications to help prevent attacks. You should work with your doctor to choose the best treatment plan for you. See Treating HAE.

Living with HAE

HAE impacts everyone differently depending on the severity of the disease as well as the frequency, type, and timing of attacks.

HAE will also affect people differently depending on what stage of their life they’re at, including:


Because HAE can be diagnosed from a very young age, children with HAE are likely to be completely reliant on their parents or guardians to help them manage, treat and understand their condition.

If you are responsible for a child with HAE, it’s recommended that you get them tested after age one for levels of two proteins that regulate the immune system:

  • C1-INH (levels of which are too low in type I HAE), and
  • C4 (may also be low in people with HAE)

Before the age of one, tests can often be inaccurate. Even if a child has no symptoms, an advance diagnosis may help you prepare and put measures in place for a possible future attack.

Doctors report that their youngest patients who have HAE attacks tend to be pre-schoolers rather than infants or toddlers. However, some people do not experience attacks until their teen years or later.

If your young child does have attacks, keep in mind that they are likely to have far more difficulty than adults in conveying feelings of discomfort, pain and other medical symptoms. So try and be alert to the changes in your child’s mood or behaviour that may herald the onset of an attack and as your child grows, help him or her identify and name prodromal symptoms (e.g. a rash or irritability), as well as any personal triggers.

If your child has HAE it is also important to inform healthcare professionals, nursery/preschool or school teachers, holiday clubs and after-school programmes.

It’s recommended that you provide a letter from your child’s doctor wherever your child plays or goes to school, to help anyone supervising your child understand his or her condition.

Download sample diagnosis letters here.

Teenage years

Hormonal and emotional changes increase during teenage years and many people report their first HAE attacks occurring during puberty. In fact, a high number of people experience changes in the location, severity and frequency of their attacks as their teenage years progress, due to changes in their surroundings and circumstances.

As teenagers develop more independence and spend more time away from home, it becomes increasingly important for them to carry personal medical information. An ID bracelet or chain, a card in a wallet or purse, and an understanding of HAE among friends can discreetly help ensure safety, without having to miss out.

When approaching adulthood, the ultimate responsibility for a young adult’s health should shift gradually from parent/guardian to the individual. This includes having a firm grasp of personal triggers, warning symptoms and treatment options, which will help when moving on to university or into the working world.


Living with HAE as an adult means understanding your specific prodromal (pre-attack) symptoms, what can trigger your attacks and how you and your doctor can best manage your condition to help you live life as normally as possible.

Although no definitive causes for HAE attacks have been established, attacks may be triggered by emotional or physical stress, surgical procedures and even mild dental work.

Changes in hormonal levels have been associated with increased HAE attacks in women, and many young women report changes in attack frequency and severity when using contraceptives that contain oestrogen.

Other medications may also impact HAE attacks, so before starting a new prescription be sure to discuss possible options with your healthcare team.


Natural hormonal changes can affect the pattern of HAE attacks and, as a result, pregnant women often experience changes in their symptoms throughout and sometimes after pregnancy.

Unfortunately, there’s no definitive way to establish how pregnancy will affect HAE in different women; some notice an increase in the frequency of attacks during pregnancy, while others see a decline in number and/or severity. Similarly, many women find that their attacks return to their previous frequency after they give birth, while others experience a permanent change.


Menopause is a time of big physiological change during which hormonal levels are altered, which can affect the frequency and/or severity of HAE attacks.

If you are considering hormone replacement therapy during this stage of your life, make sure you discuss safe treatment options with your healthcare team.

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