context: Otosclerosis is a rare condition that causes hearing loss. It happens when a small bone in your middle ear -- usually the one called the stapes -- gets stuck in place. Most of the time, this happens when bone tissue in your middle ear grows around the stapes in a way it shouldn't. Your stapes bone has to vibrate for you to hear well. When it can't do that, sound can't travel from your middle ear to your inner ear. That makes it hard for you to hear. Otosclerosis affects more than 3 million Americans. Experts aren't sure exactly what causes it. But they do know: It usually starts when you're young. You can develop otosclerosis between the ages of 10 and 45, but you're most likely to get it during your 20s. Symptoms usually are at their worst in your 30s. It often runs in families. About half of all people with otosclerosis have a gene that's linked to the condition. But even if you have the gene, you won't necessarily get it. Both men and women get otosclerosis. Women, though, have a higher risk. Experts aren't sure why, but if you're a woman and develop otosclerosis during pregnancy, you're likely to lose your hearing faster than if you were a man or you weren't pregnant. Caucasians are most likely to get it. About 10% develop otosclerosis. It's less common in other groups and rare for African- Americans. Certain medical problems can raise your chances of otosclerosis. For example, if you had measles at any time, your risk may go up. Stress fractures to the bony tissue around your inner ear also might make it more likely to happen. And immune disorders, in which your immune system mistakenly attacks parts of your body, also can be linked to the condition. The main symptom of otosclerosis is hearing loss. At first, you may notice that you can't hear low-pitched sounds or people whispering. This usually gets worse over time. Most people with otosclerosis have hearing loss in both ears. About 10% to 15% have hearing loss in just one ear. Other symptoms include: Dizziness or balance problems Tinnitus, or ringing, roaring, or hissing in your ears Sometimes tinnitus can be a problem after you have ear surgery to treat otosclerosis. If you notice you have trouble hearing, see an otolaryngologist (ear, nose, and throat doctor, or ENT). He'll look closely at your ear, test your hearing, and ask about your family health history. In some cases, he may recommend a computerized tomography ( CT) scan. A series of X-rays are taken at different angles and put together to make a more detailed image. If your otosclerosis is mild, your doctor may take a watch-and-wait approach and test your hearing regularly. She might also recommend that you get a hearing aid. Some doctors may treat otosclerosis with sodium fluoride, a dietary supplement. But this hasn't been proven to work. If your hearing loss is serious or gets worse, your doctor may recommend a surgery called a stapedectomy. With this procedure, a surgeon puts a device in your middle ear that moves the stuck stapes bone, letting sound waves travel to your inner ear so you can hear better. A stapedectomy can help some people. But like all types of surgery, it has risks. In rare cases, it can make hearing loss worse. If you have otosclerosis in both ears, a surgeon will operate on one ear at a time. After the first one, you'll need to wait at least 6 months for it to be done on your other ear.