Angioedema: What It Is and How to Act Fast

Angioedema is sudden swelling under the skin or mucous membranes. It often shows up around the eyes, lips, tongue, throat, and sometimes the hands, feet or genitals. Swelling can be itchy and painful, but the real danger is when it affects breathing or swallowing.

There are two common types: allergic (histamine-driven) and bradykinin-driven. Allergic angioedema often comes with hives and reacts to food, insect stings, or medicines. Bradykinin-driven angioedema includes hereditary angioedema (HAE) and reactions from ACE inhibitor medicines. Those don’t usually respond to antihistamines or epinephrine the same way allergic cases do.

When angioedema is an emergency

Call emergency services right away if swelling affects the tongue, throat, or you have trouble breathing, noisy breathing, drooling, or can't swallow. Fast airway compromise is the biggest risk. If someone has a known severe allergy and carries an epinephrine auto-injector, use it immediately and get emergency help.

For mild facial or lip swelling without breathing trouble, treat symptoms but watch closely for progression. If swelling spreads or you feel tightness in your throat, head to the ER.

Practical steps during an attack

If it looks allergic: give epinephrine for severe cases, then antihistamines and a steroid if advised by a clinician. Sit upright, try to stay calm, and avoid anything that could worsen breathing. If you’re the patient, tell first responders about allergies and current meds.

If angioedema may be from an ACE inhibitor (common blood pressure drugs), stop the medicine and seek medical review. These episodes can be delayed—sometimes weeks or months after starting the drug. Epinephrine and antihistamines often won’t help bradykinin cases; hospitals use specific treatments like C1-inhibitor concentrate or icatibant.

If you get recurrent unexplained swelling, ask a doctor about tests: C4 level and C1-inhibitor quantity and function can identify hereditary angioedema. Allergy testing helps when a trigger food or bite is suspected. Review your medicine list for ACE inhibitors or other culprits.

Living with recurrent angioedema means planning. Carry an emergency plan and medicines your provider recommends. Wear medical ID if you have HAE or severe allergies. Avoid known triggers, and talk to a specialist about long-term options—HAE has proven preventive drugs now that reduce attacks.

Simple actions save lives: recognize throat swelling, use epinephrine for severe allergic attacks, call emergency services, and get medical follow-up. If you have questions about medicines that can cause angioedema, or need help building an emergency plan, talk to your doctor or an allergist/immunologist.