If the gland becomes diseased or injured, it may not work properly. People are said to be hypothyroid when the thyroid gland cannot produce enough thyroid hormone. People whose thyroid glands are too active are said to be hyperthyroid . Hypothyroidism Hypothyroidism is the most common thyroid function abnormality. Having too little thyroid hormone causes your body to slow down.
Some individuals are more likely than others to become hypothyroid.
Hyperthyroi dism Hyperthyroidism occurs when your thyroid gland produces too much thyroid hormone. This commonly results from a condition known as diffuse toxic goiter or Graves disease. Other conditions that cause this include toxic nodular or multinodular goiter- in which one or more nodules in the thyroid become overactive. Another condition that may cause hyperthyroidism is called thyroiditis. If your doctor suspects that you have a thyroid disorder she or he will give you a physical exam to look for signs and symptoms.