An ear infection is inflammation inside your ear caused by bacteria or a virus
An ear infection happens when fluid builds up behind your eardrum and becomes infected. The infection causes swelling and pressure, which is why your ear hurts. Most ear infections are in the middle ear — the space behind your eardrum where three tiny bones sit. Bacteria or viruses get there when fluid that normally drains out gets trapped instead.
You do not catch an ear infection the way you catch a cold. Instead, a cold or sinus infection can block the tube (called the Eustachian tube) that drains fluid from your middle ear. When that tube stays blocked, fluid pools, and bacteria or viruses already in your nose or throat move into that trapped fluid and multiply.
Ear infections are most common in children under age three, but adults get them too. They usually clear on their own within a few days, though some need antibiotics or other treatment depending on what caused them.
Key Takeaways
- Ear infections happen when fluid behind your eardrum becomes infected with bacteria or a virus, causing pain and pressure.
- A cold, sinus infection, or allergies can block the Eustachian tube and trap fluid, which then gets infected.
- Pain, fluid drainage, and hearing problems are the most common signs, and symptoms can appear suddenly.
- Most ear infections go away without treatment, but a doctor can determine whether antibiotics or other care is needed.
- Repeated infections or fluid that does not drain may need different treatment than a single infection.
How you know you have an ear infection
The most obvious sign is ear pain — sharp, dull, or throbbing depending on how much pressure has built up. Pain often gets worse when you lie down or when you pull on your ear. Young children who cannot describe pain may tug at their ear, cry more than usual, or have trouble sleeping.
Other signs include fluid draining from your ear (sometimes with blood or pus mixed in), hearing that sounds muffled or distant, a feeling of fullness in your ear, or fever. Some people feel dizzy or off-balance. Not everyone has all these signs — some people have only pain, others only drainage.
Symptoms can start suddenly, often after a cold or upper respiratory infection. They may improve on their own within a few days or get worse over hours.
The difference between middle ear and outer ear infections
A middle ear infection (the most common type) happens behind your eardrum, where you cannot see it. You feel pain and pressure, but there is no visible sign unless fluid or pus drains out through a hole in the eardrum.
An outer ear infection (sometimes called swimmer's ear) happens in the ear canal — the tube between your eardrum and the outside world. The skin there gets infected, usually from water trapped in the canal or from scratching. Outer ear infections hurt when you touch your ear or pull on your earlobe, and you may see redness or drainage. They are less common than middle ear infections but more common in people who swim frequently.
The treatment differs between the two. Middle ear infections often need observation or antibiotics. Outer ear infections usually need antibiotic drops applied directly into the canal.
Why children get ear infections more often than adults
Children's Eustachian tubes are shorter, more horizontal, and narrower than adults' tubes. That shape makes it easier for fluid to get trapped and harder for it to drain naturally. Children also get more colds and respiratory infections, which means more chances for their Eustachian tubes to get blocked.
Adenoids — tissue in the back of the throat that helps fight infection — are larger in children and can swell during illness, further blocking the tube. As children grow, their tubes become more angled and their immune systems stronger, so ear infections become less frequent.
Some children have repeated infections (three or more in six months, or four or more in a year). This pattern may lead a doctor to recommend tubes — tiny cylinders placed through the eardrum to let fluid drain continuously.
What causes the bacteria or virus to get there
Bacteria and viruses live normally in your nose and throat. When you have a cold or sinus infection, the lining of your nose and throat swells, and mucus production increases. The Eustachian tube — which usually opens and closes to let air in and fluid out — can get squeezed shut by that swelling.
Once the tube is blocked, negative pressure builds up in your middle ear, which sucks more fluid in from the surrounding tissue. That trapped, stagnant fluid is a perfect place for bacteria or viruses to grow. Sometimes the infection starts from bacteria or viruses that travel up the tube from your nose; sometimes bacteria already in your middle ear multiply when conditions are right.
Allergies, secondhand smoke, and air pollution can also inflame the lining of your nose and throat, making blockage more likely. Lying flat (common in babies and young children) makes it harder for fluid to drain, which is why ear infections are more common in infants.
When an ear infection needs medical attention
See a doctor if you have severe ear pain, fever above 102°F, drainage from your ear, hearing loss, or symptoms that do not improve after three days. You should also see a doctor if you have repeated infections, if an infection comes back after treatment, or if you notice fluid in your ear that does not go away after a few weeks.
A doctor will look inside your ear with an otoscope (a small lighted tool) to see whether your eardrum is red or bulging, and whether fluid is present. They may use a pneumatic otoscope, which puffs a small amount of air to test whether your eardrum moves normally. Some doctors use tympanometry, a machine that measures how well your eardrum vibrates.
These tests help the doctor decide whether you have an infection, what type it is, and whether treatment is needed. Not every ear infection requires antibiotics — many clear on their own, and antibiotics do not speed recovery in those cases.
Pain relief while an infection clears
Over-the-counter pain relievers like ibuprofen or acetaminophen can reduce ear pain and fever while your body fights the infection. A warm compress held against your ear may also help. Some people find relief from a heating pad set on low, held against the outside of the ear for 10 to 15 minutes at a time.
Avoid inserting anything into your ear canal, including cotton swabs pushed deep inside. If fluid is draining, let it drain — do not try to stop it. If you swim or shower, keep water out of your ear by using a cotton ball lightly coated with petroleum jelly or an ear plug.
If your doctor prescribes antibiotics, take the full course even if you feel better after a few days. Stopping early can allow the infection to return or lead to antibiotic resistance.
Frequently Asked Questions
Can an ear infection cause permanent hearing loss?
Most ear infections cause temporary hearing loss that returns once the fluid drains. Permanent hearing loss is rare unless the infection damages the tiny bones in your middle ear or causes a hole in your eardrum that does not heal. Repeated infections over years, especially in children, can sometimes affect hearing development, which is why doctors monitor children with frequent infections.
Is it safe to fly or swim with an ear infection?
Flying is not recommended during an active ear infection because pressure changes in the cabin can increase pain and slow healing. Swimming should be avoided if you have drainage or a hole in your eardrum, since water in your middle ear can worsen the infection. Ask your doctor before flying or swimming if you are unsure.
What is the difference between an ear infection and earwax buildup?
Earwax buildup causes muffled hearing and a feeling of fullness but usually no pain or fever. An ear infection causes pain, often with fever and sometimes drainage. A doctor can look inside your ear to tell the difference. Earwax can be removed; an infection needs to be treated.
Can you get an ear infection from loud noise?
Loud noise does not cause infection, but it can damage hearing. Ear infections are caused only by bacteria or viruses. However, if you have an active ear infection, loud noise may make your ear hurt more because of the pressure already building up inside.
How long does it take for an ear infection to go away?
Most ear infections clear within one to two weeks, even without antibiotics. Some improve within a few days. If your doctor prescribes antibiotics, symptoms usually improve within 24 to 48 hours, but you should take the full course. Fluid can remain in your ear for weeks after the infection clears, which may cause mild hearing loss until it drains completely.