An underactive thyroid, or hypothyroidism, affects metabolism. It can mimic simple weight gain but has deeper health effects.

During the hypothyroid period the myasthenic weakness increased dramatically. The patient was unable to support her standing weight. Weakness of the facial muscles developed. All the muscle groups ...

The result is an overactive thyroid, or hyperthyroidism. Symptoms may include a fast heartbeat, irritability, trouble sleeping, and muscle weakness. If you’ve been diagnosed with Graves ...