Hyperthyroidism, known as overactive thyroid is the overproduction of the thyroxine hormone, which controls metabolism.  This disease affects a small gland that is located in the neck known as the thyroid gland. This condition cannot be self-diagnosed, so it is best to see a doctor for a proper diagnosis. Laboratory tests and imaging are supposed to be conducted and the appropriate treatment to be prescribed by the health expert. Symptoms of this condition usually resolve within months after treatment has begun. If left untreated, it can lead to severe complications like organ damage and bone and muscle problems.
Hyperthyroidism is mostly caused by an immune system problem called Graves’ disease.  At the initial stage, overactive thyroid may make the patient feel hot, have tremors in the hands, or lose weight. The thyroid is a small, butterfly-shaped gland located at the front of the neck. It produces two primary hormones that control how cells in the body make use of energy. The thyroid gland regulates body metabolism through the release of these hormones.
The following are the symptoms of hyperthyroidism: 
Excess sweating is a sign of overactive thyroid because of heat intolerance that happens. The thyroid gland regulates the body temperature. So, when the thyroid gland makes more thyroid hormones than the human body needs, the temperature is also likely to rise. This can lead to extra-sensitivity to heat and frequent perspiration. People who have an overactive thyroid often sweat a lot and feel uncomfortable when they are warm. Their skin is often warm and moist to the touch, and they may have thinning hair. A person suffering from hypothyroidism may struggle to keep a normal body temperature.