The thyroid gland is part of the endocrine system. It is in the neck and is responsible for producing, storing and releasing hormones into the bloodstream. In some cases, the thyroid is overactive and produces too much of the hormone thyroxine, which can speed up your metabolism. Overactive thyroid, which is also called hyperthyroidism, can be caused by several things, including medications and other medical conditions. Women are 5 to 10 times more likely than men to develop an overactive thyroid, according to the National Endocrine and Metabolic Diseases Information Service. Once hyperthyroidism is identified, several treatment options are available, depending on the cause and the severity of the condition. But to be diagnosed, one must be aware of the signs and symptoms of overactive thyroid.
Some people with an overactive thyroid may develop a goiter or thyroid nodules that make the enlarged gland visible in the neck. In some cases, the physical changes may simply appear as a swollen area at the base of the neck.
Hyperthyroidism can cause you to lose weight because your metabolism is working more quickly. You may lose weight even without any changes to your diet or physical activity level. Some people with an overactive thyroid even find themselves losing weight despite an increase in caloric intake. In rare cases, the condition can cause weight gain.
When the thyroid is overactive, you may notice yourself having more mood swings than usual. You might also be more irritable and may be anxious or have anxiety attacks. Some people with hyperthyroidism also have difficulty sleeping.
Hyperthyroidism can also cause an increase in heart rate, in some cases to more than 100 beats per minute. People with an overactive thyroid may also experience an irregular heartbeat or heart palpitations.
Another sign of an overactive thyroid is a change in your bowel patterns, most often experiencing more bowel movements than normal. Some people may also experience diarrhea.
Other signs and symptoms that can develop when your thyroid is overactive include increased sweating; increased heat sensitivity; muscle tremors, most often in the fingers and hands; muscle weakness; and fatigue. In women, it can also disrupt the menstrual cycle.