In this article:
- A quick guide to ear anatomy
- Does Hashimoto's thyroiditis cause hearing loss?
- Diagnosing and treating hearing loss secondary to Hashimoto's
Hashimoto's thyroiditis is the most common cause of hypothyroidism. This autoimmune condition occurs when your immune system mistakenly attacks your thyroid gland with white blood cells and antibodies. Overtime, autoimmunity leads to chronic thyroid inflammation, which makes it challenging to produce thyroid hormones. If Hashimoto's is left untreated, it can lead to hypothyroidism which affects virtually every system in your body, including your ears.
A quick guide to ear anatomy
The ear is a highly sophisticated sensory organ that transmits sound to your brain and helps to maintain your balance. There are three parts to your ear: external ear, middle ear, and inner ear.
The external (or outer) ear is where sounds transmit through your ear canal to your eardrum (or tympanic membrane). The eardrum is highly sensitive to pressure changes from sound waves, which cause it to vibrate. The ear canal is where we have earwax to collect dust and debris from reaching our tympanic membrane.
The middle ear contains three small bones - the hammer (malleus), anvil (incus), and stirrup (stapes). It also has the oval window and the eustachian tube. When your eardrum vibrates, the three bones in the middle ear further transmit the sound waves to the oval window, a membrane that covers the entrance to the inner ear. The purpose of the middle ear is to amplify sound waves before they enter the inner ear. The eustachian tube helps you equalize pressure, so it does not build up between your eardrum and oval window.
The inner ear is essentially a maze and is called the labyrinth. The labyrinth contains the cochlea, the auditory nerve, and the vestibular. The cochlea looks like a snail shell and contains fluid that moves microscopic hairs. The auditory nerve carries information from the cochlea to the brain. The vestibular is a 3-ringed passage with fluid that helps detect different movements in our body. Complications in the vestibular can cause you to feel dizzy and off-balance.
Does Hashimoto's cause hearing loss?
Autoimmune diseases can sometimes cause hearing loss. However, there is still quite a bit of mystery as to why autoimmunity impairs this sensory organ. We do know that the immune system can affect hearing by:
- Attacking just the tissues in the ear, or
- Causing secondary damage to the ear from other autoimmune conditions like Hashimoto's, Sjogren's syndrome, systemic lupus erythematosus, and rheumatoid arthritis.
Hearing loss can also be from debris transported by the circulatory and lymphatic system from other tissues and collects in the ears' small fluid-filled organs. Debris can lead to vestibular (balance) disorders, which can cause dizziness. Interestingly, people with hypothyroidism often are diagnosed with Meniere's disease, which is a condition involving hearing loss and vertigo.
Hearing loss is much more common in people with hypothyroidism compared to the general population. Some estimates suggest that at least 25% of people with acquired hypothyroidism have some degree of hearing loss. In contrast, 30-50% of people with congenital hypothyroidism who are born with hearing loss. Fortunately, early detection and treatment of congenital hypothyroidism can improve hearing in people with this condition.
Diagnosing and treating hearing loss secondary to Hashimoto's
We know that the thyroid gland affects every organ system in our body. And when we have too little thyroid hormone circulating in our bloodstream, it can disrupt some of our most essential functions, including metabolism, growth and development, reproduction, and even cognitive function. If you have Hashimoto's, you not only need to combat low thyroid hormones but also manage thyroid autoimmunity, which can wreak havoc in organs beyond your thyroid.
If you notice that you are struggling with hearing loss and have Hashimoto's, you must make sure you are on the right thyroid medication dose. People with hypothyroidism and Hashimoto's must take thyroid hormone medication. Some studies find that the hearing of people with untreated hypothyroidism and symptoms of hearing loss improves when they start levothyroxine therapy. Meet with your thyroid doctor to verify that you are on the right dose of thyroid medication.
Of course, hearing loss may also be from many other factors unrelated to your thyroid. Some causes of hearing loss include:
- Inner ear damage (as seen with aging and chronic exposure to loud noises)
- Abnormal bone growths or tumors
- Ruptured eardrum
- Ear wax build-up or a foreign body in the external canal
You are likely to be referred to a hearing specialist who will perform a physical exam of your ear and perform general screening tests that may include the following:
- A whisper test
- Tuning fork tests
- Audiometer tests
A hearing specialist may recommend ear wax removal, hearing aids, or cochlear implants if you have hearing loss that does not improve with managing your thyroid. Some people also undergo surgery to correct structural abnormalities.
Remember, several things can cause hearing loss. If you notice that your hearing is worsening, meet with your doctor right away. Early diagnosis and treatment is the key to restoring this essential sensory function.