What are the causes of an ear infection?
Updated: Aug 15
Multiple causes can lead to an ear infection. This blog will comprehensively explain each of the 20 causes of ear infections.
Adenoids - Most common ear infection cause in children
Smoking - active and passive
Untreated Common Cold
The most common ear infection cause is the common cold. When we catch a cold, the mucus can travel from the back of our nose into the eustachian tube or auditory tube, which leads to the middle ear. The mucus entering the middle ear can cause an infection known as Otitis media.
90% of the ear infections spread from nose to ear. This makes middle ear infections or otitis media.
If you want to avoid getting a middle ear infection, you can take steps to treat your common cold. One effective method is to do steam inhalations thrice daily for just five minutes. Using nasal decongestants can also help prevent these infections. To learn more about easy ways to prevent middle ear infections, click now.
Blowing nose very hard
When we blow our nose too hard, mainly when one nostril is blocked, it creates high pressure in the back of our nose, called the nasopharynx. This pressure can force infected fluid from the nasopharynx into the middle ear through the eustachian or auditory tube. The fluid can stagnate and become a breeding ground for bacteria, leading to an ear infection known as Otitis media or middle ear infection.
In chronic sinusitis, less mucus may present since the body's immune system has found a way to manage the infection without eliminating it. Unlike acute sinusitis, where fluids are flushed out through the nose, in chronic sinusitis, fluid is pushed from the back of the nose into the throat. The nasopharynx, located at the back of the nose, contains the opening of a eustachian or auditory tube that goes to the middle ear. This tube can be blocked if the mucus is thick, causing negative pressure in the middle ear. The negative pressure can result in ear pain and infection. If the fluid is thin, it can still travel to the middle ear and cause an infection. Either way, the fluid entering the auditory tube can lead to a middle ear infection.
Read our article "Ear pain or clogged ears with a sinus infection."
The nose, throat, breathing pathway, lungs, voice box, and back of the nose (nasopharynx) are all connected by one continuous layer of skin called the mucosa. Allergies can affect all these areas but may affect one area more than others. The mucosa lining from the back of the nose also goes to the eustachian or auditory tube. During an allergy, the mucosa can swell, causing the eustachian or auditory tube to become partially blocked or smaller. This can restrict air circulation to the middle ear, leading to negative pressure, which can cause fluid from the blood to seep into the middle ear. These fluids can stagnate, and bacteria can grow in them, causing an ear infection called Otitis Media in the middle of the ear.
The ear canal can be infiltrated by bacteria present in the environment, leading to an ear infection known as Otitis externa. This infection can potentially spread from the outer ear to the middle and inner ear.
Bacteria can cause infections in the nose, such as rhinitis or the common cold. If left untreated, this infection can travel from the back of the nose to the middle ear through the auditory tube, causing a middle ear infection.
While bacterial and fungal infections are more commonly associated with ear infections, it is also possible for viruses to infect the outer ear canal and cause an ear infection. However, viral ear infections are less frequent than bacterial and fungal infections.
A virus can infect the nose, often resulting in the common cold. If the common cold is not properly treated, it can lead to a middle ear infection.
Fungus - Otomycosis
If your ear is exposed to fungal spores and there is some humidity or water and ear wax in your ear, then the fungus can grow and use the ear wax as food. This causes pain and itching; if left untreated, it can lead to a perforated ear drum and hearing loss. This type of ear infection caused by fungus is called Otomycosis. Two types of fungi can cause Otomycosis: Aspergillus Niger, which is black-colored, and Candida, which is white-colored. Aspergillus Niger is the more common of the two.
Extra growth or tumor in the back of the nose where the eustachian tube opens
The middle ear is connected to the back of the nose, called the nasopharynx, by a tube called the auditory tube or eustachian tube. Air enters the middle ear through this tube whenever we swallow food or saliva. However, if there is a mass in the nasopharynx, it can block the opening of the tube and prevent the flow of air into the middle ear. This blockage causes negative pressure to build up in the middle ear, which can cause fluid from the blood to seep into the middle ear. The fluid can then stagnate and provide a breeding ground for bacteria, leading to an infection in the middle ear called Otitis Media.
Adenoids - Most common ear infection's cause in children
Adenoids, which are glands located in the back of the nasal cavity, can also block the opening of the eustachian tube and causes negative pressure in the middle ear. The eustachian tube is responsible for supplying air to the middle ear, and when it is blocked, the air supply is cut off, causing negative pressure to build up. This can cause pain and allow fluids to seep into the middle ear, leading to the stagnation of liquids. Stagnant fluids can then provide a breeding ground for bacteria, leading to an infection in the middle ear called Otitis Media.
Oil in ear
Many people use home remedies like pouring oil in the ear to alleviate itchy ears, assuming that the itchiness is due to dryness, which may be true. However, it could also be caused by a fungal infection in the outer ear canal called Otomycosis. If the itchiness is due to a fungal ear infection, adding oil can actually feed the fungus and promote its growth. Even if the itchiness is caused by dryness, adding oil can still lead to a fungal ear infection. Typically, there is a balance between the naturally occurring fungus and bacteria in our ears. However, adding oil can upset this balance by providing food for the fungus, allowing it to grow rapidly and overpower the bacteria. This can lead to the fungus eating the wax in our ear, invading the skin and eardrum.
Water in ear
When water enters the ear while swimming or showering, it can facilitate the growth of any fungus that may be present in the ear. The fungus requires moisture and nutrients to thrive, and the wax in our ears can provide a food source for the fungus. Typically, fungal infections affect the outer ear canal and can even perforate the eardrum. These infections are called Otomycosis and are characterized by severe itching, pain, and eventually deafness due to the perforation of the eardrum.
Using external objects like cotton buds to clear the ear canal
Using external objects, such as cotton buds, to clean the ears can cause damage to the delicate skin in the ear canal and make it more vulnerable to infections. This is particularly true after showering, as the wet skin in the ear canal can be more fragile and prone to rupturing. When the skin is damaged, it creates an opportunity for fungi to grow and thrive in the outer ear, leading to a condition known as Otomycosis.
Otomycosis is a fungal infection that affects the outer ear canal and can cause severe itching, pain, and hearing loss. The presence of water in the ear, along with the ruptured skin, provides a favorable environment for the fungi to flourish. Therefore, it is essential to avoid using external objects to clean the ear canal and instead use safe methods recommended by healthcare professionals to prevent ear infections.
Humid climates can indeed increase the likelihood of fungal growth in the ear canal, leading to Otomycosis. This fungal ear infection is often caused by fungi such as Aspergillus Niger, which is black-colored, or Candida, which is white-colored.
In fact, Otomycosis is the second most common ear infection in humid areas, where the high moisture content promotes fungal growth. In contrast, in non-humid areas, bacterial infections of the outer ear canal are the second most common type of ear infection. It is essential to take preventive measures, such as keeping the ears dry, avoiding the use of external objects for cleaning the ear canal, and seeking prompt medical attention if any ear infection symptoms appear to prevent Otomycosis and other ear infections.
Infection in brain
In rare instances, an infection in the brain can spread to the inner ear, which can cause hearing loss and vertigo or loss of balance. Unfortunately, the reverse can also happen, where an infection in the inner ear can spread to the brain.
When someone has uncontrolled diabetes for a prolonged period, their immune system becomes weak and less efficient in fighting off infections. Similarly, there could be other conditions like AIDS that can lead to low immunity. As a result, even mild bacteria can cause infections, including ear infections. The disease can start in the outer ear and spread to the middle and inner ear or directly in the middle ear.
Going to a hilly area at high speed / High-speed elevator over 20 floors / Diving into the water / Traveling in flight
The four situations mentioned above - going to a hilly area quickly, riding a fast elevator over 20 floors, diving into the water, and traveling in a plane - can cause sudden changes in air pressure.
If you have a partially blocked eustachian tube due to allergies, structural issues from birth, or sinusitis, it can cause a mismatch between the air pressure in your middle ear and the outside air pressure. This means that the eustachian tube can't equalize the pressure in your middle ear with the external pressure.
As a result, fluid from your blood can seep into your middle ear, causing it to get trapped and not flow properly. The fluid stagnation can allow bacteria to grow, leading to an ear infection called Otitis Media.
Active or passive smoking can cause inflammation of the mucosa lining that goes through the nose, throat, nasopharynx (back of the nose), voice box, and lungs. This same mucosa also lines the eustachian or auditory tube, which opens in the nasopharynx. When inflamed, the inflamed mucosa can cause blockage of the eustachian tube, leading to negative pressure in the middle ear. The negative pressure can cause fluids from the blood to seep into the middle ear, leading to fluid stagnation and bacterial growth, resulting in an ear infection called Otitis Media.
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Where does an ear infection start?
Ear infections can start from different parts of the ear. In most cases, ear infections start in the middle ear. Middle ear infections are secondary infections triggered by a common cold or chronic sinusitis. As the infection progresses, it can spread to other ear parts.
The external ear is the second most common place for an ear infection to start. This outer ear infection can either be bacterial or fungal.
On the other hand, the inner ear is the least common location for an infection to start. It usually occurs as a secondary infection, like a middle ear infection. However, the infection in the inner ear can spread from the brain to the inner ear in very rare cases. In most inner ear infection cases, the spread is from the middle ear to the inner ear.
It's essential to identify the symptoms of an ear infection and seek timely medical assistance to prevent complications.
What is the most common ear infection?
The most common ear infection is the one that affects the middle ear, i.e., otitis media. This secondary infection mostly occurs due to an untreated common cold.
Otitis media is then succeeded by infections of the external ear. Otitis externa, a bacterial infection, is the second most common ear infection in non-humid or non-coastal regions. Otomycosis, a fungal infection, is the second most common ear infection in humid or coastal areas.
What happens if you ignore an ear infection?
If you ignore an ear infection, it can propagate to different parts of the ear and cause severe complications such as perforation of the eardrum, damage to the middle ear bones (stapes, incus, malleus), and permanent hearing impairment. The spread of the infection to the inner ear can also result in tinnitus and vertigo and, in severe cases, even lead to brain infection.
As a result, affected individuals may require hearing aids, surgery, or a combination of both. Therefore, it is essential to seek prompt medical attention if one suspects an ear infection.
Can blowing a nose cause ear pain?
Yes, blowing the nose can cause ear pain. Blowing a nose hard when a person has a common cold can cause otitis media, resulting in ear pain.
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