The medical term for ear infection is otitis media, and it is more common in children than in adults. However, adults are still susceptible to these infections. Ear infections occur when viruses or bacteria get into the space behind the eardrum (middle ear).

Causes
The most common triggers of an ear infection include colds, allergies, and other respiratory viral infections. Various other causes of otitis media or ear infection include

• Eustachian tube dysfunction
  The Eustachian tube is a part of the ear that is behind the eardrum. It is a passageway that runs from the middle ear to the back of the throat (nasopharynx). They are responsible for equalizing ear pressure and draining fluid from the middle ear and are usually closed except for when you yawn, chew, or swallow. If the Eustachian tube is blocked, fluid or bacteria gets trapped inside the ear and causes ear infections. Eustachian tube dysfunction is more common in children because the Eustachian tube in children runs at a more horizontal angle than in adults, so the secretions or the fluids in the middle ear don’t drain well. This explains why children are easily accessible to ear infections. The main reason for Eustachian tube dysfunction is a common cold. If a person gets a cold, the Eustachian tubes are blocked. This, in turn, blocks the mucus from draining, leading to the growth of bacteria and viruses in the mucus. The viruses and bacteria cause the formation of pus, which builds up in the middle ear causing an ear infection.
• Bacteria and viruses
  If the fluids in the ear are not drained well, it becomes the breeding ground for bacteria. Once the bacteria are trapped inside the middle ear, it causes an ear infection. The most common bacteria that cause ear infections are Streptococcus pneumonia (most commonly spreads during winter season causing respiratory infections) and Haemophilus influenza, Moraxella catarrhalis (causes infections of the respiratory system, including middle ear), and Staphylococcus aureus (found in the upper respiratory tract). Viruses that cause ear infections may include rhinoviruses (cold viruses), respiratory syncytial virus (viruses that cause respiratory tract infections), influenza virus, and enteroviruses (infects the central nervous system).

Symptoms
Typically, ear pain is the main symptom of an ear infection. Since the ear infection and upper respiratory tract infection are connected with each other, there are chances of accompanying symptoms like a cough and nasal discharge. This is why the ear infection usually begins when the child is suffering from a severe cold for a long time. Other common symptoms include

• Headache
• Hearing loss
• Fussiness in infants
• Discomfort inside the ear
• A feeling of pressure inside the ear
• Pus-like ear drainage and swelling behind the ear

It’s difficult to detect signs of ear infection in children and infants. However, you may notice certain actions such as the child is constantly touching the ear, scratching or holding the ear. Also, many children feel irritable and cry constantly, because ear infections are usually painful. In certain cases, ear infections resolve within a few days. But, if the pain isn’t getting better, and if the child is running a fever, it is necessary to check with the doctor as soon as you can.