Hyperparathyroidism occurs when one or more of your parathyroid glands produce an excessive amount of parathyroid hormone, which results in the rise of calcium levels in the blood. These glands are approximately the size of a grain of rice and are located behind the thyroid at the base of your neck. The parathyroid hormone helps maintain calcium in the blood and tissues that depend on calcium for proper function. In the early stages of the disease, symptoms are often absent. Your provider may recommend surgery to remove the hyperactive gland if you have more severe hyperparathyroidism symptoms, an enlarged parathyroid gland (or glands), or a growth on your parathyroid gland(s).
There are two types of hyperparathyroidism.
Primary Hyperparathyroidism: Overproduction of the parathyroid hormone is caused by an enlargement of one or more parathyroid glands. This results in elevated calcium levels in the blood, leading to a variety of health issues.
Secondary Hyperparathyroidism: It develops due to another condition that causes low calcium levels in the body. Increased parathyroid hormone levels develop over time.
Hyperparathyroidism can be caused by a problem with the parathyroid glands (primary hyperparathyroidism) or a condition that affects the glands' function (secondary hyperparathyroidism). Calcium and phosphorus levels in the body are regulated by the parathyroid glands by secretion of parathyroid hormone (PTH). Vitamin D is also involved in regulating calcium levels in the blood. This balancing act usually works well. Calcium is mainly recognized for its role in keeping your teeth and bones healthy. On the other hand, calcium helps nerve cells transmit signals and is involved in muscular contraction. Another mineral, phosphorus, works in conjunction with calcium in these regions.
Your parathyroid glands produce enough PTH to restore equilibrium when calcium levels in your blood fall too low. PTH raises calcium levels by releasing calcium from bones and boosting calcium absorption in the small intestine.
The parathyroid glands produce less PTH when blood calcium levels are too high. However, one or more of these glands can sometimes produce too much hormone. This causes your blood to have unusually high calcium and low phosphorus levels.
Primary Hyperthyroidism: A problem with one or more of the four parathyroid glands causes primary hyperparathyroidism, which may include:
Secondary Hyperparathyroidism: It is caused if another condition decreases calcium levels in the body. To compensate for the calcium loss, your parathyroid glands overwork. Secondary hyperparathyroidism can be caused by several factors, including:
Severe calcium deficiency: Your body may not be getting enough calcium from your diet, which is frequently due to calcium not being absorbed by your digestive system.
Severe vitamin D deficiency: Vitamin D keeps calcium levels in the blood at a healthy level. It also helps absorb calcium from food through your digestive system. Vitamin D is produced by the body when the skin is exposed to sunlight, and it is also present in some of the foods we eat. Calcium levels may drop if you don't obtain enough vitamin D.
Chronic kidney failure: Vitamin D is converted into a form that your body can utilize by your kidneys. If your kidneys aren't working correctly, your usable vitamin D levels will drop, and your calcium levels will drop, leading your parathyroid hormone levels to rise. PTH levels are reduced by some medications, such as vitamin D, bisphosphonates, and cinacalcet.
In some people with long-term end-stage kidney failure, the parathyroid glands enlarge and start releasing PTH on their own, and PTH does not respond to medical treatment. This is known as tertiary hyperparathyroidism, and it may require surgery to remove parathyroid tissue.
You may be at risk for primary hyperparathyroidism if:
Hyperparathyroidism is often diagnosed before symptoms or signs of the condition appear. Symptoms can be mild and nonspecific, or they can be severe and appear to be unrelated to parathyroid function. They are often caused by damage or dysfunction in other organs or tissues due to high calcium levels in the blood and urine or inadequate calcium levels in the bones. The following are some of the signs and symptoms:
Blood tests: If your blood test results suggest that you have high calcium levels in your blood, your doctor will most likely repeat the test after you haven't eaten for a while to confirm the results. A variety of factors can raise calcium levels. However, if blood tests show high parathyroid hormone levels, your doctor can diagnose hyperparathyroidism.
Urine tests: A 24-hour urine sample can show how well your kidneys are working and how much calcium is excreted in your urine. This test may help determine the severity of hyperparathyroidism or detect a renal problem that causes the condition. An extremely low calcium level in the urine may indicate a condition that doesn't require treatment.
Bone mineral density test: It determines if you have osteoporosis. Dual-energy X-ray absorptiometry (DEXA) is the most popular test for determining the bone mineral density and is used to measure how many grams of calcium and other bone minerals are packed into a bone segment using special X-ray devices.
Imaging tests: To see if you have kidney stones or other kidney problems, your doctor may perform an X-ray or other imaging studies of your abdomen.
Surgery: The most common treatment for primary hyperparathyroidism is surgery, which is effective in most cases. The surgeon may recommend removing only the affected gland. If all four glands are affected, a surgeon will most likely remove only three and possibly a portion of the fourth, leaving some working parathyroid tissue behind. You may be able to go home the same day if your surgery is performed as an outpatient procedure. In such cases, the surgery can be performed using local anesthetics and very minor cuts (incisions) in the neck.
Medications: The following medications are used to treat hyperparathyroidism:
Calcimimetics: It is a drug that mimics calcium in the blood. The medication could cause the parathyroid glands to produce less parathyroid hormone. Cinacalcet is the brand name for this medication (Sensipar). Some doctors may use cinacalcet to treat primary hyperparathyroidism, especially if surgery has failed to cure the illness or if the patient is not suitable for surgery.
Bisphosphonates: Bisphosphonates prevent calcium loss from bones and may reduce the risk of osteoporosis caused by hyperparathyroidism. Low blood pressure, a fever, and vomiting are some of the side effects of bisphosphonates. This medication does not address the underlying problems with the parathyroid glands.
Hormone replacement therapy: Hormone replacement therapy may help bones retain calcium in women who have gone through menopause and show signs of osteoporosis. Hormone replacement therapy can raise your risk of blood clots and breast cancer if you use it for a long time. Assess the risks and benefits with your doctor to help you determine what's best for you. Breast pain and tenderness, dizziness, and headaches are common adverse effects of hormone replacement therapy. However, this medication does not address the underlying problems with the parathyroid glands.
The main complications of hyperparathyroidism are the long-term effects of too little calcium in your bones and too much calcium in your blood. Among the most common complications are:
The following tips may help you prevent complications:
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 21, 2023.
Primary Hyperparathyroidism - NIDDK (nih.gov)
Management of Primary Hyperparathyroidism - Bilezikian - 2022 - Journal of Bone and Mineral Research - Wiley Online Library