Hypothyroidism, also known as underactive thyroid, is not as common as you might think and comes with quite a few symptoms, including cold intolerance, weight gain, coarse hair, loss of hair, depression, and fatigue, among others. Even less common is hyperthyroidism which is where your thyroid gland is overactive. Hyperthyroidism causes severe insomnia which then leads to fatigue just like hypothyroidism.
Many people believe they suffer from either of these two medical conditions, when in fact, their symptoms are caused by other ailments. Nevertheless, if you are not feeling well, a screening test for thyroid disease is inexpensive and straightforward.