A number of health conditions can cause or worsen tinnitus. In many cases, an exact cause is never found.
Common causes of tinnitus
In many people, tinnitus is caused by one of the following:
Hearing loss. There are tiny, delicate hair cells in your inner ear (cochlea) that move when your ear receives sound waves. This movement triggers electrical signals along the nerve from your ear to your brain (auditory nerve). Your brain interprets these signals as sound.
If the hairs inside your inner ear are bent or broken — this happens as you age or when you are regularly exposed to loud sounds — they can "leak" random electrical impulses to your brain, causing tinnitus.
Ear infection or ear canal blockage. Your ear canals can become blocked with a buildup of fluid (ear infection), earwax, dirt or other foreign materials. A blockage can change the pressure in your ear, causing tinnitus.
Head or neck injuries. Head or neck trauma can affect the inner ear, hearing nerves or brain function linked to hearing. Such injuries usually cause tinnitus in only one ear.
Medications. A number of medications may cause or worsen tinnitus. Generally, the higher the dose of these medications, the worse tinnitus becomes. Often the unwanted noise disappears when you stop using these drugs.
Medications known to cause tinnitus include nonsteroidal anti-inflammatory drugs (NSAIDs) and certain antibiotics, cancer drugs, water pills (diuretics), antimalarial drugs and antidepressants.
Other causes of tinnitus
Less common causes of tinnitus include other ear problems, chronic health conditions, and injuries or conditions that affect the nerves in your ear or the hearing center in your brain.
Meniere's disease. Tinnitus can be an early indicator of Meniere's disease, an inner ear disorder that may be caused by abnormal inner ear fluid pressure.
Eustachian tube dysfunction. In this condition, the tube in your ear connecting the middle ear to your upper throat remains expanded all the time, which can make your ear feel full.
Ear bone changes. Stiffening of the bones in your middle ear (otosclerosis) may affect your hearing and cause tinnitus. This condition, caused by abnormal bone growth, tends to run in families.
Muscle spasms in the inner ear. Muscles in the inner ear can tense up (spasm), which can result in tinnitus, hearing loss and a feeling of fullness in the ear. This sometimes happens for no explainable reason, but can also be caused by neurologic diseases, including multiple sclerosis.
Temporomandibular joint (TMJ) disorders. Problems with the TMJ, the joint on each side of your head in front of your ears, where your lower jawbone meets your skull, can cause tinnitus.
Acoustic neuroma or other head and neck tumors. Acoustic neuroma is a noncancerous (benign) tumor that develops on the cranial nerve that runs from your brain to your inner ear and controls balance and hearing. Other head, neck or brain tumors can also cause tinnitus.
Blood vessel disorders. Conditions that affect your blood vessels — such as atherosclerosis, high blood pressure, or kinked or malformed blood vessels — can cause blood to move through your veins and arteries with more force. These blood flow changes can cause tinnitus or make tinnitus more noticeable.
Other chronic conditions. Conditions including diabetes, thyroid problems, migraines, anemia, and autoimmune disorders such as rheumatoid arthritis and lupus have all been associated with tinnitus.
