Ask the Doctors by Eve Glazier, M.D. and Elizabeth Ko, M.D

Hair Loss Could Be Caused by Multitude of Issues

Dear Doctor: I've been taking thyroid medication for several years, and my doctor says my blood tests are where they should be, but my face feels like sandpaper, my nails are brittle, and I'm losing so much hair that I can see my scalp. Could there be some underlying problem my physician is missing?

Dear Reader: Hair loss can be a distressing symptom, made all the more so when its cause is a mystery.

Your thyroid hormone levels are an obvious place to start, because both low and high thyroid levels can lead to hair and nail changes. Symptoms of high thyroid levels include hair loss, skin that is unusually smooth and warm, and nails that soften and loosen from the nail bed. The remaining hair becomes thinner, softer and does not hold a wave. Symptoms of low thyroid levels also include hair loss, including in the armpits and genital area, but the hair in this scenario is dull, coarse and fragile. As for the nails, they tend to be delicate, thin and have multiple grooves. That said, if your physician has done a complete panel of thyroid tests and the results have been normal, then most likely the function of your thyroid gland is not the cause of the brittle nails nor the hair loss.

That doesn't mean the thyroid isn't a factor. Autoimmune thyroid disease can lead to hair loss, both patchy and more diffuse, as well as inflammatory conditions of the skin. Such disease isn't always reflected in thyroid hormone levels. Checking anti-thyroid antibodies in the blood can identify autoimmune thyroid disease, and point you and your doctor in a clearer direction.

Hair loss also can be caused by androgenic alopecia, linked to an excess of androgens, a type of male hormone. These hormones are present in both men and women, but they're higher than normal in some women, such as those with congenital adrenal hyperplasia or polycystic ovarian disease, which is relatively common. Simply checking levels of testosterone and dehydroepiandrosterone (DHEA) can either rule out androgenic alopecia or suggest that it be explored further.

Another potential cause is medication. Some medications can lead to hair loss, so if your symptoms seem coincidental to starting a new medication, there might be an association.

Biotin deficiency, which is rare, can also cause hair loss and inflammation of the facial skin. But if you have a normal diet and eat eggs, you have a low likelihood of this condition. Nonetheless, it's something to rule out.

Iron deficiency also can lead to both brittle nails and hair loss. This doesn't explain the skin manifestations that you have, but if you are looking at other possibilities, checking the iron level of the blood should be part of the workup.

Any major illness can lead to hair loss and nail changes, and psychological stress can lead to hair loss. So, if there have been major stressors in your life, either physical or psychological, consider that a potential culprit.

In summary, if your thyroid levels are normal, it would be wise to check your thyroid antibodies, androgens and iron levels -- and your level of stress.

(Send your questions to, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)