Hypothyroid and Hyperthyroid
The most common functional abnormality of the thyroid gland is hypothyroidism. This occurs when the thyroid gland makes too little thyroid hormone. Common symptoms of hypothyroidism may include fatigue, unexplained weight gain, intolerance of cold, constipation, dry skin, brittle hair, joint and muscle pains, or difficulty with concentration.
A less common abnormality of the thyroid gland is hyperthyroidism. This occurs when the thyroid gland makes too much thyroid hormone. Common symptoms of hyperthyroidism may include racing heart, hand tremor, intolerance of heat, unexplained weight loss, anxiety, or insomnia. There are many different reasons why the thyroid glandmight make too much or too little thyroid hormone.