Having hereditary angioedema (HAE) may increase your risk of developing other health conditions too, including autoimmune and heart-related diseases. Knowing about these possible connections may help you recognize symptoms earlier, ask questions, and manage your overall health.

Here’s a closer look at health conditions that may be related to hereditary angioedema.

Conditions That Can Occur With Hereditary Angioedema

Autoimmune diseases, asthma, and allergies are some of the most common conditions reported alongside HAE. One study found that more than two-thirds of people with HAE had at least one autoimmune disease, asthma, or allergies.

Researchers are still studying why HAE seems to be linked to autoimmune diseases. One idea is that the most common types of HAE involve C1 inhibitor (C1INH), a protein that helps regulate parts of the immune system. When this protein is low or doesn’t work as expected, immune-system activity may be affected.

It’s possible to develop many different autoimmune conditions when you have HAE. However, systemic lupus erythematosus (SLE) — the most common form of lupus — appears to be one of the most common autoimmune diseases reported in people with HAE types 1 and 2.

Symptoms of SLE can come and go and change over time, but some of the more common ones include:

• Rashes
• Painful joints
• Extreme fatigue
• Low-grade fevers

Researchers aren’t sure why SLE and HAE can occur together. One idea is that people with the most common types of HAE may have low levels of certain proteins, such as C4. These proteins help the body fight infections and diseases.

A deficiency in C4 may interfere with some of the immune system’s normal protective processes. This may help explain why C4 deficiency is linked with a higher risk of autoimmune conditions such as lupus.

Allergies and asthma seem to be more common in people with HAE. One survey found that 54 percent of people with HAE reported having allergies, compared with 27 percent of people in the general population.

In the same survey, 17 percent of people with HAE reported having asthma, which was also higher than the general population.

Researchers are still studying this connection. One possible reason is that HAE symptoms can sometimes be mistaken for allergic reactions, especially before someone receives an HAE diagnosis. For example, swelling in the face, lips, throat, or abdomen may lead some people to first see an allergist.

Some studies have reported that people with HAE are more likely to develop autoimmune thyroid disease (ATD). ATD occurs when your immune system attacks your thyroid. There are two main types of ATD — Graves’ disease and Hashimoto’s thyroiditis.

Symptoms often depend on the type you have. Hashimoto’s may cause a swollen thyroid, fatigue, and achy joints, while Graves’ disease can cause heart palpitations, tremors, and bulging eyes.

Sjögren’s disease is another chronic autoimmune disease that can occur alongside HAE. Sjögren’s develops when your immune system attacks the glands that produce moisture for your body, such as your tear ducts and salivary glands.

Common symptoms of Sjögren’s disease include:

• Dry eyes, nose, mouth, and/or skin
• Vaginal dryness
• Frequent nosebleeds
• Frequent coughing

People with HAE tend to have a higher risk for some cardiovascular conditions.

Hypertension (high blood pressure) occurs when blood pushes against the walls of your blood vessels with a force that’s consistently too high.

Because high blood pressure often doesn’t cause any symptoms, many people don’t realize they have it. If left untreated, high blood pressure can lead to heart attack and stroke.

One study found that people with HAE were more likely to have high blood pressure than people without HAE. They were also more likely to take medications to treat it. The researchers noted this may be because people with HAE often see healthcare providers more regularly and may be more aware of their blood pressure.

Cholesterol is a type of lipid, or fat, that helps your body perform different functions. When cholesterol levels are too high, cholesterol can contribute to plaque buildup in the arteries. This can increase the risk of heart disease.

Like high blood pressure, high cholesterol may be more common in people with HAE. One study found that people with HAE were more likely to have high cholesterol. They were also more likely to be taking medications to treat it.

Thrombosis happens when a blood clot forms inside a blood vessel. In some cases, a clot can block blood flow and lead to serious health problems, such as deep vein thrombosis, pulmonary embolism, heart attack, or stroke.

Some research suggests that people with HAE may have a higher risk of thromboembolic disease, a group of conditions caused by blood clots.

Researchers say this may be related to low levels of the C1INH protein, which helps processes involved in blood clotting, among other systems in the body. When C1INH inhibitor levels are low or the protein does not work properly, these clotting-related processes may be affected.

Because blood clots can be serious, talk with your healthcare provider if you have symptoms such as:

• Swelling
• Shortness of breath
• Chest pain
• Coughing up blood

HAE can also affect your mental health. Living with a rare condition that causes sudden and painful swelling attacks can be stressful and unpredictable. Some people may worry about when the next attack will happen, how severe it will be, or whether they’ll need emergency care.

Research suggests that people with HAE may have higher rates of anxiety and depression than people in the general population.

These mental health conditions may be related to the burden of managing HAE, missing work or school, avoiding certain activities, or feeling isolated because others may not understand the condition.

Symptoms of depression and anxiety can vary, but they may include:

• Persistent sadness or hopelessness
• Excessive worry or fear
• Trouble sleeping
• Loss of interest in activities
• Difficulty concentrating
• Changes in appetite or energy

People with HAE may be at a higher risk of developing sleep disorders, including insomnia (difficulty falling asleep or staying asleep) and sleep apnea (a condition in which breathing repeatedly stops and starts during sleep).

Some people with HAE may also experience poor-quality sleep. Swelling attacks can happen at night and may interrupt sleep, especially if they cause pain, discomfort, or breathing concerns.

HAE may also affect sleep if symptoms interfere with daily routines, cause stress, or lead to fatigue. Poor sleep can make it harder to manage your overall health and may worsen mood, energy levels, and quality of life.

Sleep problems may include:

• Trouble falling asleep
• Waking up during the night
• Feeling tired after a full night’s sleep

Join the Conversation

On myHAEteam, people share their experiences with hereditary angioedema, get advice, and find support from others who understand.

If you’re living with HAE, have you been diagnosed with any other health conditions? Let others know in the comments below.