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Both men and women can get this condition. But an underactive thyroid is very common among women.

As many as 1 in 10 women over 60 have a mildly underactive thyroid without any symptoms.^{1 2}

Having an underactive thyroid is the second most common hormone problem in the US. (Diabetes is the most common.)

It's more common to have a mildly underactive thyroid without any symptoms (mild hypothyroidism). If you have symptoms it's called overt hypothyroidism. Both kinds of underactive thyroid get more common as you get older.

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment. ©BMJ Publishing Group Limited 2008. All rights reserved.