(HealthDay News) -- When the thyroid gland produces too little of a hormone that helps maintain the body's metabolism, it causes a condition called hypothyroidism.
Symptoms of an underactive thyroid may include unexpected weight gain, severe weakness or fatigue, pain in the joints and muscles, and brittle hair and fingernails. As the condition progresses, people may also have swelling in the face and neck, speech problems and hardening skin, the U.S. National Library of Medicine says.
If you have these symptoms, it's important to see a doctor without delay.
