6 Lesser-known and Better-known Causes of Hearing Loss

Hearing loss can be a symptom of many other conditions. Some, like diabetes, we know a lot about. And some we’re just recently beginning to understand.

Lesser-known causes of hearing loss

Iron-deficiency anemia

Hearing loss has been in the news recently because of the results of a recent study linking it to iron-deficiency anemia. This study found that iron-deficiency anemia was associated with an 82 percent higher chance of sensorineural hearing loss. In cases of sensorineural hearing loss, there is damage to the inner ear or the nerves leading from the inner ear to the brain. The study didn’t determine that iron-deficiency anemia definitely causes hearing loss, but it suggested that the lack of iron may reduce blood flow to the inner ear.

Several groups of people are at particular risk for iron-deficiency anemia, including:

• Babies and young children, especially premature babies or those with a low birth weight
• People who get kidney dialysis treatment
• People who have internal bleeding because of colorectal cancer, bleeding ulcers or other medical conditions
• People whose diets don’t contain enough iron
• Women of childbearing age who have regular menstrual cycles

Otosclerosis

Another cause of hearing loss that most people don’t know about is otosclerosis. Otosclerosis is a condition in which one of the ossicles, or the tiny bones in the middle ear, gets stuck and isn’t able to vibrate normally. This normally happens to the ossicle called the stapes. When these bones can’t vibrate, sound can’t travel through the ear to the auditory nerve, which carries signals to the brain that allow us to hear. This is a type of conductive hearing loss.

Otosclerosis tends to occur in people with a family history of the condition. Researchers think otosclerosis also could be associated with previous cases of measles, stress fractures to the bony area around the inner ear and immune disorders. Some researchers also believe a lack of fluoride in drinking water can contribute to the development of otosclerosis.

Better-known causes of hearing loss

Unfortunately, numerous factors can cause or contribute to hearing loss. Some of the better-known ones include:

• Ototoxins
• Ear infections and cholesteatomas
• Microvascular disease
• Age

Ototoxins

One fairly common cause of hearing loss is exposure to chemicals or medications that can damage the ear. We call these ototoxic substances or ototoxins. Many medications and chemicals can cause either temporary or permanent ear damage, including:

• Aspirin
• Certain antibiotics, including gentamicin and vancomycin
• Cisplatin and carboplatin, used in chemotherapy for cancer treatment
• Loop diuretics, used to treat some kidney and heart conditions
• Quinine, used to treat malaria

Ear infections and cholesteatomas

Untreated ear conditions like ear infections can also lead to hearing loss without proper treatment. Ear infections are a common childhood illness, but some adults continue to get them as they age. This can be linked to a condition called Eustachian tube dysfunction, which happens when the tube that links the nose to the middle ear doesn’t open or close properly. Adults with Eustachian tube dysfunction are at higher risk for ear infections.

Chronic ear infections can lead to the development of a cholesteatoma. A cholesteatoma is a cyst of skin in the middle ear space, or mastoid. Someone with a cholesteatoma might have painless ear drainage that they just might get used to over time. But without treatment, the cholesteatoma can break down the bones in the middle and inner ear. Not only can this cause hearing loss, but a cholesteatoma also can cause:

• Brain infection, or encephalitis
• Dizziness or a lack of balance
• Facial paralysis, resembling Bell’s palsy
• Meningitis

Diabetes, high blood pressure and high cholesterol

Hearing loss is linked to several fairly common conditions, including diabetes; high blood pressure, also known as hypertension; and high cholesterol, also known as hyperlipidemia. All of these conditions can cause microvascular disease, which is a problem with the tiny blood vessels that supply blood to the inner ear. Microvascular disease of the ear’s blood vessels can narrow these inner-ear blood vessels, which can either cause hearing loss or cause it to get worse.

Age

Of course, perhaps the best-known cause of hearing loss has to do with the aging process. Our risk for hearing loss goes up as we get older. This is called age-related hearing loss, also known as presbycusis. Almost 25 percent of Americans between 65 and 74 have some degree of hearing loss. And nearly half of Americans 75 and older have hearing loss.