Hyperthyroidism and hypothyroidism -arise from the production of abnormally high (hyper) or low (hypo) levels of thyroxine
hyperthyroidism- an excess of thyroxine production Symptoms: lethargic (low energy), gain weight, less heat, irritable
Grave’s disease- cause of 50% of cases- an autoimmune disorder in which antibodies attach to TSH receptors on thyroid cell increasing production of thyroid hormones.
Hypothyroidism- a deficiency of thyroxine production. Symptoms: hyper, lose weight, hot, sweat, wide-eyed, insomnia, increased heart rate,
Goiter- lack of iodine preventing the thyroid gland from producing thyroxine. Pituitary gland releases more TSH causing growth and swelling of the thyroid gland. Symptoms: enlarged thyroid gland, coughing, choking feeling.

The Endocrine System