Rashes are areas of irritated or swollen skin that can be red, itchy, and painful. They can result from various causes, including infections, allergic reactions, irritants, autoimmune conditions, or underlying health issues. Common types of rashes include contact dermatitis, eczema, heat rash, and drug rashes. Treatment involves identifying and addressing the underlying cause, using topical or oral medications to reduce inflammation and itching, and adopting preventive measures to avoid future outbreaks.