Hyperthyroidism can also be caused by: thyroid gland inflammation, too much iodine intake, taking too much thyroid hormone medication, overactive thyroid nodules, also known as toxic nodular goitre or multinodular goitre, non-cancerous pituitary gland tumour.
Excessive thyroid hormone production may lead to symptoms that can include restlessness, nervousness, racing heart rate, irritability, increased sweating, shaking, anxiety, troubled sleeping, thin skin, brittle hair and nails, muscle weakness, weight loss, increased appetite, frequent bowel movements, bulging eyes (in Graves’ disease), etc.
Hypothyroidism is just the opposite of hyperthyroidism. Our thyroid gland is underactive and can’t produce enough of its hormones. This can cause some of our body functions to slow down.
It is often caused by Hashimoto’s thyroiditis, a surgery that removes the thyroid gland, or damage from radiation treatment. It can also be caused by thyroiditis, congenital hypothyroidism, meaning that you can be born with the condition, iodine deficiency, pituitary gland or hypothalamus disorders, medications, including heart medications, cancer medications, and bipolar disorder medications.