The thyroid is a butterfly-shaped gland in the neck that converts iodine from food to a hormone that regulates the body’s energy production and consumption. The parathyroid, located within the thyroid, is a group of four tiny glands that control calcium levels in the blood. Both play a crucial role in maintaining many of the body’s day-to-day functions.
The thyroid gland is responsible for controlling the body’s metabolism. It removes iodine from the blood and converts it to thyroid hormone. The thyroid works in conjunction with both the pituitary and hypothalamus glands in the brain to regulate the amounts of hormone released to the body. Too much or too little thyroid hormone can cause serious medical problems.
An overactive thyroid gland occurs when excessive thyroid hormone is produced. This condition, known as hyperthyroidism, causes the metabolism to speed up, resulting in a rapid or irregular heartbeat, nervousness, irritability, fatigue, sweating, tremors, weight loss, increased bowel movements and heat intolerance. There are several common causes including Grave’s disease (an autoimmune disorder that interferes with the thyroid’s ability to respond to the pituitary gland), nodules and goiter, abnormal secretion of TSH (thyroid stimulating hormone) by the pituitary gland, thyroiditis (inflammation of the thyroid gland) and excessive iodine intake. Treatment usually involves beta-blockers, iodide, methimiaole, or radioactive iodine therapy.
By contrast, an underactive thyroid gland results in abnormally low amounts of thyroid hormone production. The condition, called hypothyroidism, causes the metabolism to slow down. This leads to fatigue, depression, constipation, muscle aches and pains, facial puffiness, dry skin, sensitivity to cold, swelling of the legs and weight gain. Some of the conditions that can cause this include Hashimoto’s thyroiditis (an autoimmune disorder in which the immune system attacks the thyroid tissue), lymphocytic thyroiditis (inflamed thyroid gland), thyroid destruction following surgery, disease or injury of the pituitary gland, hypothalamic disease, and too little iodine in the diet. The most common treatment involves synthetic hormone replacement therapy.
They may have similar sounding names, but the thyroid and parathyroid glands are responsible for regulating entirely different hormones. The parathyroid glands secrete parathyroid hormone (PTH), which helps to maintain the proper ratio of calcium and phosphorous in the body. These play a crucial role in bone and tooth development and strength. Like the thyroid gland, the parathyroid sometimes produces too much or too little of this hormone, resulting in medical complications.
Hyperparathyroidism occurs when overactive parathyroid glands secrete too much PTH, causing calcium levels in the blood to rise, while phosphorous levels dip. This can boost calcium amounts in the urine and lead to painful kidney stones. In addition, the bones may lose calcium. Symptoms include osteoporosis, lack of energy, weakness, abdominal pain, bone and joint pain, depression, loss of appetite, constipation, loss of concentration, nausea and vomiting. What causes hyperparathyroidism is unknown. The usual treatment method is surgical removal of the enlarged gland or glands. Fortunately, the success rate for this procedure tops 90%.
Too little PTH is the hallmark of hypoparathyroidism, which causes low calcium levels in the blood (and a corresponding increase in phosphorous). Signs include a tingling or burning sensation in the fingertips, toes, and lips; muscle aches and cramps; weakness and fatigue; anxiety; headaches; muscle spasm; dry and brittle hair and nails; cataracts; mood swings; depression and memory loss. Injury to the parathyroid glands is the most common cause, with the trauma frequently sustained during head and neck surgery. Calcium carbonate and vitamin D supplements are used to return calcium and phosphorous levels in the body to normal levels.