The parathyroid glands are different than the thyroid gland, even though the names are similar. The four parathyroid glands are usually on the back of the thyroid gland, but they can be located around the jaw or neck.
Parathyroid glands secrete a hormone called PHT. The PHT regulates the exchange of calcium between the blood and the bones. When the parathyroid gland is over active, too much calcium is pulled out of the bones. This is called hyperparathyroidism or parathyroid disease.
Bones need calcium for strength. The brain needs calcium to think and muscles need calcium to contract. Too little calcium in the bones will cause a serious condition called osteoporosis (brittle bone disease). Too much calcium in the blood increases the risk of having a stroke and can make people feel sick.
Symptoms of hyperparathyroidism include:
- No symptoms at all
- Confusion, foggy thinking
- Muscle cramps. A tingling sensation in the hands and feet.
- Loss of energy, always tired
- Trouble sleeping, waking up at night.
- Feeling bad, but not able to say the reason
- Loss of interest in activities, inability to concentrate
- Changes in personality, more irritable or cranky
- Bone pain, especially in the legs
- Heartburn (GERD)
- Decreased sex drive
- Frequent headaches
- Thinning hair
- Heart palpitations (arrhythmias), high blood pressure
- Blood calcium levels should never be elevated. Even a slightly elevated calcium level is not normal. People with slightly elevated calcium levels may still have a diseased parathyroid gland.
Causes and Risk Factors
The cause of most parathyroid adenomas is not known. Hyerparathyroidism most commonly develops during ages 40 to 75, but it can occur any age. The average age is 59.
These factors can also increase the risk:
- Heredity. If other family members had hyperparathyroidism, you are at greater risk to develop the disease.
- Multiple endocrine neoplasia syndromes (MEN1, MEN2a, MEN2b). These are conditions that can make tumors grow in the parathyroid glands, pituitary glands and the pancreas. The condition is also called multiple endocrine adenomatosis and Wermer's syndrome. It is usually inherited (runs in the family).
- A history of radioactive iodine therapy used for thyroid cancer treatment.
- A childhood history of radiation treatments for acne or other condition in the head and neck area (common in the 1940s to 1950s).
- Radiation exposure from nuclear power plant accidents or other sources.
Parathyroid hyperplasia is a different condition than hyperparathyroidism. With hyperplasia all four parathyroid glands grow larger, but an adenoma does not grow inside the glands. There is no known cause. Long term use of Lithium (a psychiatric drug) may increase the risk of developing hyperplasia.
Doctors measure the parathyroid hormone and the calcium hormone to diagnose hyperparathyroid disease. If both are elevated, that indicates a tumor (adenoma) is growing. An adenoma might still be growing if the parathyroid hormone level is normal.
A Sestamibi Scan helps to identify which parathyroid gland is diseased. Your doctor might also order a parathyroid MRI.
Parathyroid glands rarely develop cancer, but the enlarged gland must be removed because it increases calcium in the blood. Medication cannot control the calcium levels. Surgery is the only treatment.
People can function normally with only ½ of 1 parathyroid gland.
Standard parathyroid surgery requires a 6 to 8 inch incision in the lower part of the neck.
Minimally invasive parathyroid surgery (MIRP) uses a special probe to locate the diseased gland. MIRP requires only a 1 inch incision.