The small, butterfly-shaped gland that resides at the base of the neck is the thyroid gland. Its main function is to regulate metabolism, or how quickly the body consumes energy. The thyroid can cause problems if it either produces too much hormone and speeds up the body's metabolism, or produces too little hormone and does not provide the body with enough energy. In either case, a bad thyroid gland can cause several types of problems.
Problems with Mental State
Improper metabolism caused by a malfunctioning thyroid can severely effect mood, mental functioning and energy levels, according to MedlinePlus, a publication of the National Institutes of Health. People with hyperthyroidism, resulting in an overactive metabolism, will often experience irritability, nervousness, restlessness and anxiety, as well as problems sleeping. In contrast, people with slow metabolisms caused by hypothyroidism often experience fatigue, constantly feeling tired and weak. Depression may also occur, as well as forgetfulness and memory problems.
Weight Problems
A bad thyroid gland often causes weight changes. People with a hyperactive thyroid will often experience an increase in appetite and will eat more food than normal. Even with this increased food intake, they may lose weight. Bowel movements may occur more frequently, as well as diarrhea, in some cases. On the other hand, people with hypothyroidism and a sluggish thyroid gland may gain weight, even while eating less than usual, the Cleveland Clinic reports. Constipation is another problem that may result from hypothyroidism.
Menstruation Problems
Women with a bad thyroid gland will often experience problems with their menstrual periods. Hyperthyroidism in women may cause the menstrual period to happen very infrequently and with a lighter flow volume. In some cases, the menstrual period may stop altogether, according to WomensHealth.gov. In contrast, women with hypothyroidism often experience very heavy menstrual periods that occur more frequently than normal.
Other Physical Problems
Several other physical problems may result from a bad thyroid. In cases of hyperthyroidism, the thyroid gland may swell, sticking out of the back of the neck, causing a goiter. In other cases, eye irritation and problems with vision may occur. Muscles in the hands or elsewhere may tremble and spasm, which can lead to muscle weakness. Because the thyroid glad also regulates the heart, hyperthyroidism may cause a rapid or irregular heartbeat. In the opposite case of hypothyroidism, people may experience a general, dull joint and muscle pain. A hoarse voice is another common physical problem, as well as dry, pale skin and a swollen or puffy face.
Temperature Problems
Hyperthyroidism often causes people to sweat excessively. In addition, people with an overactive thyroid gland may not be able to tolerate warm temperatures. In contrast, people with an underactive thyroid gland often cannot tolerate cold temperatures, the Cleveland Clinic notes.
