1. A chemical compound released by cells in the body during allergic reactions and inflammation, causing itching, swelling, and other symptoms.
Usage: biochemistry; medicine

Examples

• When you have an allergic reaction, your body releases histamine, which causes itching and swelling.
• Antihistamine medications work by blocking the effects of histamine in the body.
• Histamine levels increase during an asthma attack, making breathing more difficult.
• The doctor explained that histamine is responsible for the hives on her skin.
• Some foods naturally contain high levels of histamine and can trigger reactions in sensitive people.
• Histamine plays an important role in regulating sleep and appetite in the brain.