Since the earliest times, humanity has been on the move. Today, more people than ever before live in a country other than the one in which they were born.

Common thyroid disorders include Hashimoto's disease, Graves' disease, and goiter. Learn about their symptoms, diagnosis, and treatments.

The effects on health of prolonged but low level exposure to carbon monoxide (CO) are unclear. Studies of carbon monoxide exposure focus mainly on short term effects in experimental settings, or on ...