First AIDFIRST AI DOCTORYour care companion
Health library/Hereditary angioedema

Rare immune disorders / RARE CONDITION

Hereditary angioedema

Also known as: C1 esterase inhibitor deficiency, C1 inhibitor deficiency, HAE, HANE, Hereditary angioneurotic edema

Hereditary angioedema causes recurring episodes of swelling in skin or internal tissues. Airway involvement can become life-threatening even without an itchy allergic rash.

Save to my health notebook +

Save after unlocking your private notebook. An article bookmark does not add a diagnosis.

What you may notice

Symptoms can overlap with other conditions and vary between people.

  • Limb or facial swelling
  • Severe abdominal pain
  • Vomiting
  • Throat swelling

Understanding care

Clinical care may include specialist confirmation and an individualized prevention and emergency plan. A qualified clinician decides which investigations and options fit the individual situation.

When to seek help

Throat swelling, voice change or breathing difficulty requires emergency services immediately. Do not wait for hives or a doctor match; follow an existing prescribed emergency plan.

For severe breathing difficulty, collapse, suspected stroke, or another emergency, call local emergency services immediately. In India, call 112.

Read the medical sources

These sources support the educational article and offer more detail.

Educational reading · Updated 6 October 2026

Prepared from the linked sources. This summary has not had an independent clinician review. A qualified clinician can assess symptoms and explain which information applies to you.

A child and a caring grown-up reading a picture book together

LITTLE PEOPLE. BIG FEELINGS.

It’s okay to have
a lot of questions.

A doctor visit or an unfamiliar health word can feel scary. You can ask a trusted grown-up to help you understand, one small question at a time.

01

Say how you feel.

“I feel worried” is a good place to start.

02

Ask for simple words.

“Can you explain that in a way I understand?”

03

Bring someone you trust.

A caring adult can help you ask and listen.

For children and their grown-ups. This illustration explains a conversation, not a diagnosis. An adult should seek qualified care for a child who is unwell.

Hereditary angioedema — First AID health library