Hair growth depends on the proper functioning of the thyroid gland, so abnormal levels of thyroid hormone produced by this gland can result in hair changes, along with other side effects. When there is too much thyroid hormone (hyperthyroidism), you may see thinning hair all over the scalp. On the other hand, people with too little thyroid hormone (hypothyroidism), especially women, may see more extreme hair loss, not just on the scalp but also on other areas of the body, including the outer edges of the eyebrow.
Thyroid disease may cause dry, itchy scalp and brittle hair, as well as weight gain or loss, fatigue or sleeplessness, and many other symptoms.
For some people rapid hair loss is the worst symptom of their thyroid problem – the thinning hair, large amounts of hair falling out in the shower or sink, often accompanied by changes in the hair’s texture, making it dry, coarse, or easily tangled.
Women are five times more likely to be diagnosed with hypothyroidism than men and the odds increase with age.
Thyroid Medications and Hair Loss
Ironically, not only do imbalances of thyroid hormones cause thinning hair, but thyroid medications can actually cause hair loss. However, users generally report that hair loss is more common within the first month of starting the medication, and is usually temporary. As thyroid hormone levels stabilize, hair growth generally returns to normal.
If you have a thyroid condition and are concerned about the amount of hair you are losing, by all means take necessary steps to get evaluated.
Get Evaluated by a Dermatologist
Even if you are in the midst of dealing with a thyroid problem, it’s still a good idea to see a dermatologist. An expert dermatologist experienced in hair loss can do a complete workup in order to assess the various causes of hair loss, and run tests that may identify other autoimmune conditions besides thyroid that may cause hair loss.