Food allergies are immune system reactions that occur when the body mistakenly identifies a specific food protein as harmful and mounts a defensive response. Even small amounts of the triggering food can cause symptoms, which may include hives, itching, swelling of the lips or throat, abdominal pain, vomiting, diarrhea, or respiratory difficulties. In severe cases, a life-threatening reaction known as anaphylaxis can occur, leading to breathing problems, a sudden drop in blood pressure, and loss of consciousness. Common food allergens include peanuts, tree nuts, milk, eggs, wheat, soy, fish, and shellfish. Food allergies differ from food intolerances, as they involve the immune system and can cause rapid and potentially serious reactions.