Mental or Emotional Stress

Emotional stress has been shown to be one of the most common triggers of HAE attacks. In one study of people living with type 1 or type 2 HAE, mental stress was the most common trigger of abdominal swelling, linked to 27 percent of abdominal HAE attacks.

Stress may trigger HAE attacks because of how the body reacts to stressful situations. During stress, the body releases hormones such as cortisol and adrenaline as part of its fight-or-flight response. If you have HAE, you may notice that these changes are linked to a swelling attack.

Living with HAE can also be stressful because attacks can be unpredictable. People with the condition may worry about when their next attack will happen, how severe it will be, whether it will disrupt daily life, or whether it could affect the airway.

This can create a cycle in which worry about HAE increases stress. In some people, that stress may then play a role in triggering more HAE attacks.

Physical Trauma or Mechanical Stress

Physical trauma and mechanical stress — such as pressure, impact, strain, or friction on the body’s tissues — are also recognized triggers of HAE attacks. People with HAE may find that injuries or activities that place extra pressure or force on certain parts of the body can lead to attacks.

Surgery and dental procedures are well-known HAE attack triggers. Repetitive physical activities, such as shoveling or hammering, may also trigger attacks. Even a mild activity like typing at a computer can trigger HAE attacks for some people.

Infections

Illness — especially viral upper respiratory infections, such as influenza (the flu) or the common cold — can also trigger HAE attacks for some people.

In one study, infection was one of the most common triggers of upper airway swelling in people with type 1 HAE or type 2 HAE, accounting for 26 percent of these attacks.

When you’re sick or injured, your body may respond with physical stress, including changes in stress hormones such as cortisol and adrenaline, as well as immune system changes. For some people with HAE, this may contribute to a swelling attack.

Hormones

The hormone estrogen may play a role in HAE symptoms, and hormone-related changes can affect attack patterns in some people. Estrogen is known to affect pathways involved in bradykinin.

Estrogen naturally rises at points during the menstrual cycle, and this can trigger HAE attacks in some people. Hormone levels can also change during life stages such as puberty and perimenopause. These changes may lead to more swelling attacks in some people, but the effect of menopause itself can vary from person to person.

Hormone-related triggers of HAE attacks may include:

• Puberty
• Menstruation (periods)
• Ovulation (the release of an egg from an ovary during the menstrual cycle)
• Pregnancy
• Perimenopause and menopause

Medications

Some people with HAE may find that certain medications trigger swelling attacks. Medications that may trigger or worsen HAE attacks include:

• Hormonal medications that contain estrogen, such as some birth control pills and hormone replacement therapy
• Certain blood pressure medications called ACE inhibitors
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen

Exercise

Some people may find that physical activity triggers their HAE attacks. Because of this, it’s important to talk with your doctor before starting a new exercise routine if you have HAE.

One small study noted that 62 percent of people with HAE who took part in recreational sports, such as running, hiking, biking, and strength training, reported that these activities made their HAE worse.

Diet

Research suggests that diet may be an under-recognized trigger of HAE attacks. The small study mentioned above found that 23 percent of people with HAE reported their swelling attacks were triggered by certain foods or drinks.

In a separate study of people with type 1 HAE or type 2 HAE, participants reported that the following foods and drinks triggered swelling attacks:

• Coffee
• Alcohol
• Dairy products
• Spicy foods
• Fatty foods
• Legumes
• Walnuts
• Tomatoes
• Onions
• Garlic
• Gluten

Weather

Some triggers may be harder to avoid than others. Research suggests that weather changes may trigger attacks for some people with HAE. In one study published in the Orphanet Journal of Rare Diseases, 15 percent of participants with type 1 HAE or type 2 HAE reported that weather changes triggered HAE attacks.

Fatigue

Getting enough rest is important for everyone, but it may be especially important for some people with HAE. In the same Orphanet Journal of Rare Diseases study, 6 percent of participants with type 1 HAE or type 2 HAE reported that fatigue (extreme tiredness) triggered HAE attacks.