According to retired hormone specialist Marla Ahlgrimm, thyroid disorder is a relatively common condition. The thyroid, which is a gland in the back of the throat, may produce too much or too little thyroid hormone.
Hyperthyroidism
When the thyroid gland produces too much metabolizing hormones, people may be diagnosed with hyperthyroidism. This is often caused, says Marla Ahlgrimm, by Graves’ disease, tumors, or thyroiditis. Hyperthyroidism can result in irritability, reduced menstruation, frequent bowel activity, and an increase in appetite.