About 66,000 Americans  are surprised each year by a diagnosis of sudden sensorineural hearing loss, or sudden deafness. A new study, published in the journal JAMA Otolaryngology–Head & Neck Surgery, suggests it isn’t as rare as some think — occurring in up to 20 per 100,000 people.

Too few people know the risks, experts say — even though sudden deafness should be viewed as a health emergency. Medical experts say if they see patients early and treat them with [steroids], they can bring back some hearing.

But most people don’t consider it urgent and go weeks before seeking medical care — if they go to the doctor at all.

The message that a sudden drop in hearing or new ringing in your ears is also an emergency needs to get out.

One reason a drop in hearing should be treated as a medical emergency is that it might belie a more serious health problem.

The precise cause of sudden deafness is still mysterious, but researchers have two main theories: One is that a virus leads to an inflammatory response in the inner ear, and that inflammation stuns the sensory cells that enable hearing.

A second theory is that decreased blood flow to the ear results in hearing loss.

A minority of cases are brought on by viral infections (from Lyme to measles, rubella, even tuberculosis), a head and neck tumor, circulatory problems, autoimmune diseases (like Lupus), or an inner ear disorder (like Ménière’s disease).

But when doctors rule out these potential factors — taking a health history, and doing a physical exam and an MRI — they find the vast majority of patients (85 to 90 percent) have no identifiable cause for their hearing loss.

They either wake up with it or they’re doing a normal daily activity when they notice a pop, click, or crackle in their ear, preceded by static or ringing. Then they can’t hear as well out of that ear, and they may eventually show up at the doctor complaining about a clogged ear.

In reality, the nerves that enable hearing have died off or are on the edge of death, and the plugged feeling is caused by hearing. The mechanism is similar to sudden blindness, sudden paralysis of a vocal cord, or sudden loss of eye movement. All are cranial nerves known to shut off suddenly for unknown reasons.”

The hearing loss that results from sudden deafness can range from mild to severe. Sudden deafness requires urgent care because it can sometimes be reversible.

Decreasing inflammation and restoring blood flow in the ear, through the use of oral or injection steroids, can often restore at least some hearing. Other treatments, like hyperbaric oxygen therapy, are also showing promise when they accompany steroids.

If you’re worried about a hearing drop in one ear, there’s a simple test you can do to tell whether it’s caused by a blockage or something more serious: hum aloud.

If you hear your voice louder in the blocked ear, you have nothing to worry about, say medical experts. You probably have temporary hearing loss from wax, fluid, or water, and your hearing will return when your cold goes away or the wax clears. But if your voice sounds louder in the good ear, you have an emergency and need to be seen by an ENT.

Source: www.vox.com