An ear infection occurs when germs, such as bacteria or viruses, invade the middle ear, leading to inflammation and fluid buildup. This condition is common in children but can affect people of all ages. Symptoms may include ear pain, difficulty hearing, and sometimes fever. There are two main types of ear infections: otitis media, which affects the middle ear, and otitis externa, also known as swimmer's ear, which affects the outer ear canal. Treatment often involves pain relief and, in some cases, antibiotics if a bacterial infection is present.