Tinnitus

The most common causes of tinnitus can be broken down into four different types. These are:

• Conditions related to hearing loss. There are small, fragile hair cells in the inner ear, called the cochlea, that move when sound waves enter the ear. This movement triggers electrical signals along the nerve from the ear to the brain, called the auditory nerve. The brain interprets these signals as sound.

  Age or regular exposure to loud sounds can bend or break the hairs inside the inner ear. Once bent or broken, they can then "leak" random electrical impulses to the brain, causing tinnitus. About 9 of 10 people with tinnitus have some hearing loss caused by noise.

• Medicines harmful to the ear. Some medicines may cause or worsen tinnitus. Generally, the higher the dose of these medicines, the worse tinnitus becomes. Usually medicines will cause tinnitus in both ears. Often the unwanted noise goes away when you stop using these medicines.

  Medicines and substances known to cause or worsen tinnitus include:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Some antibiotics.
  • Cancer medicines.
  • Water pills, called diuretics.
  • Medicines used to treat malaria.
  • Some antidepressants.
  • Marijuana.
  • Tobacco.
  • Some herbal supplements.

• Conditions related to ear structure and function. Some examples of these types of conditions include:

  • Ear infections. These are infections typically caused by bacteria or viruses that infect the middle ear, often following a cold, flu or allergies.
  • Ear canal blockage. A blockage of wax, dirt or other foreign materials can change the pressure in the ear, causing tinnitus.
  • Problems with the eustachian tube. The eustachian (u-STAY-shun) tube connects the middle of the ear to the back of the throat. Sometimes losing large amounts of body weight or having radiation treatment near the nose and throat can cause the eustachian tube to not work correctly.
  • Conditions that affect the temporomandibular joint (TMJ). There is a temporomandibular (tem-puh-roe-man-DIB-u-lur) joint on both sides of the head in front of the ears, where the lower jawbone meets the skull. Issues with the TMJ can cause tinnitus.
  • Changes to ear bones. Stiffening of the bones in the middle ear, called otosclerosis, may affect hearing and cause tinnitus, either in one or both ears. This condition, caused by unusual bone growth, tends to run in families.
  • Muscle spasms in the inner ear. Muscles in the inner ear can tense up or spasm, sometimes causing tinnitus, hearing loss and a feeling of fullness in the ear. This sometimes happens for no clear reason, but it can be caused by brain and nervous system diseases such as multiple sclerosis.

• Conditions related to blood vessels. Blood flow changes can cause tinnitus or make it louder. One type of tinnitus, called pulsatile tinnitus, is usually caused by conditions related to blood vessels, also called vascular conditions.

  Some of the vascular conditions that can lead to or affect tinnitus are the buildup of fats, cholesterol and other substances in artery walls, called atherosclerosis, high blood pressure, and kinked or malformed blood vessels.

Less common causes of tinnitus include other ear conditions, 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 sign of Meniere's disease, an inner ear condition that may be caused by inner ear fluid pressure.
• 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.
• Migraines. A type of migraine headache called vestibular migraine, can cause dizziness, a loss of balance called vertigo, and tinnitus.
• Acoustic neuroma or other head and neck tumors. Acoustic neuroma is a noncancerous, also called benign, tumor. It grows on the cranial nerve that runs from the brain to the inner ear and affects balance and hearing. Other head, neck or brain tumors also can cause tinnitus.
• Other chronic conditions. Conditions such as diabetes, thyroid conditions, migraines, anemia, and autoimmune conditions such as rheumatoid arthritis and lupus have all been connected with tinnitus.