There are several different types of ear infections. These include:

• Otitis media. Results from inflammation and fluid buildup in the middle ear. If enough bacteria grow in the area, the fluid may become infected. Otitis media is the most common type of ear infection in young children, occurring most often between the ages of 6 months and 24 months. About 75 percent of children develop otitis media by the time they are 3 years old, and half of these children have three or more ear infections during this time, according to the National Institutes of Health. This makes otitis media the most common illness in babies and young children.
  
  Otitis media occurs when viruses, fungi or bacteria cause the eustachian tubes to swell and become blocked. Without air traveling to or from the middle ear, pressure inside the ear increases. This can be extremely uncomfortable and may feel as if the ear is a blown-up balloon, ready to pop. Middle ear infections also cause fluid accumulation and pus production within the middle ear. This may restrict the ability of sound vibrations to travel from the eardrum to the inner ear, causing temporary hearing loss.
  
  In addition, the eardrum may turn pink or red, and fluid buildup and pus produced in the middle ear may press against the eardrum, causing it to stretch tightly or to bulge. However, fluid buildup in the middle ear may also occur without an infection, often as the result of excess fluid produced during a previous episode of a cold or the flu. This form is called otitis media with effusionotitis media with effusion. Otitis media with effusion sometimes precedes an episode of otitis media and almost always follows it (e.g., fluid remains in the ear even after an infection clears). All middle ear infections may be acute (a single, short episode) or chronic (in which infections recur).
  
  
• Otitis externa. Also called swimmer’s ear or external otitis, it is an inflammation, irritation or infection of the ear canal (passageway that carries sound from outside the body to the eardrum) and/or outer ear (the visible part of the ear, including the earlobe). Despite its nickname, it can occur without swimming. Anything that causes microorganisms to enter a break in the lining of the ear canal or anywhere on the outer ear can cause swimmer’s ear.
  
  Infection occurs in the outer ear when the ear canal is exposed to excess moisture that causes an overgrowth of the bacteria and fungi that normally exist within the ear canal. Skin can become soggy, diluting the acidity normally present in the lining of the ear canal that helps prevent infection. This can lead to inflammation of the ear canal that may extend to the outer ear, causing pain. Fluid may also become trapped in the ear canal due to a buildup of ear wax.
  
  Other factors that may cause this condition include scratches or abrasions from objects (including hearing aids and ear plugs) placed into the ear canal or from physical injury to the outer ear. It can also occur from exposure to irritating chemicals (e.g., hairspray, hair dye) or contaminated water.  The excessive removal of ear wax from the ear canal can also lead to otitis externa. Outer ear infections are common in both children and adults.
  
  
• Labyrinthitis. Infection of the inner ear that affects balance and hearing. It is rare and may occur in two different forms:
  
  
• Viral labyrinthitis. Inner ear infection caused by viruses (e.g., viruses that cause the measles, mumps or flu). Viral labyrinthitis usually resolves on its own, without treatment, and leaves no long-term complications.
  
  
• Bacterial labyrinthitis. Inner ear infection caused by bacteria, such as when a middle ear infection (otitis media) spreads to the inner ear, or as the result of the spread of meningitis (inflammation of the protective cover of the brain and spinal cord). Significant permanent hearing loss is a common result of bacterial labyrinthitis, as well as damage to the structures within the inner ear. It is very rare due to the use of antibiotics to treat middle ear infections. However, it may still occur as a complication of bacterial meningitis.