CSU is a skin condition that causes hives and swelling lasting six weeks or more. The cause of the condition is often unknown, but in the majority of cases it's linked to an overactive immune system.

Angioedema is deep swelling that occurs when fluid builds up under your skin or mucus membranes. It may affect your face, throat, gastrointestinal tract, or other parts of your body. Angioedema may ...