Acute otitis media or ear infection is often a viral or bacterial infection affecting the middle ear or the air-filled space behind the eardrum containing vibrating bones. An ear infection usually infects children more than adults and can be painful due to the fluid buildup in the middle ear, which causes inflammation.

Causes
Ear infections caused due to viruses or bacterium in the middle ear might result into another illness in the form of flu, cold, or another allergy. The infection might eventually lead to a swelling of the nasal passage, throat, and eustachian tubes and may also lead to congestion. Factors such as age, group child care, infant feeding, seasonal factors, and poor air quality increase the risk of suffering from an ear infection. The following are some complications that might arise if the ear infection is not given timely treatment.

• Developmental delays
  Children and toddlers might experience a delay in speech and social developmental skills due to temporary or permanent hearing issues in infants and toddlers.
• Impaired hearing
  Temporary hearing loss is one of the most common symptoms of an ear infection. The hearing ability returns after the condition is treated. The extent of hearing loss depends on the persistent fluid present in the middle ear.
• Tearing of the eardrum
  Chronic symptoms of ear infection can lead to tearing in the eardrums, which heals within 72 hours. However, some cases might require surgery.

Symptoms
It is observed that children experience a wide range of signs and symptoms as compared to adults. Common signs and symptoms of ear infection in children include ear pain, difficulty in sleeping, loss of balance, headache, loss of appetite, and drainage of the fluid from the ear. Adults exhibit fewer symptoms, including ear pain, diminished hearing, and drainage of fluid from the ear.

Diagnosis
Doctors diagnose ear infection based on the symptoms exhibited by the patient. The following are some procedures used to diagnose ear infection:

• Pneumatic otoscope
  It is a specialized tool that enables the doctors to look into the ear and examine whether there is excess fluid behind the eardrum. The doctor uses this instrument and gently puffs air in the eardrum. If the middle ear is filled with fluid, the eardrum will show no movement, which conforms ear infection.
• Tympanometry
  It measures the movement of the eardrum. The eardrum alters the air pressure in the canal, thereby causing the eardrum to move. Tympanometry quantifies how well the eardrum responds to change in the pressure of the middle ear.
• Acoustic reflectometry
  The test measures how much sound is reflected from the eardrum. It gives an indirect estimation of the amount of fluid present in the middle ear. The eardrum absorbs most of the sound emanating from an audio source. More the fluid in the middle ear, more sound the eardrum will reflect.

These tests can lead to a diagnosis of three results: acute otitis media shows signs of fluid in the middle ear due to bacterial or viral infection. Otitis media with effusion indicates that there is fluid in the middle ear but no signs of ear infection are present. Chronic suppurative otitis media is for chronic symptoms of an ear infection that have resulted in tearing or perforation of the eardrum.