Hyperparathyroidism

Symptoms of hyperparathyroidism sometimes may be so mild that they're hard to notice. Or the symptoms may seem like they're related to another health concern. If hyperparathyroidism isn't treated, symptoms might get worse over time.

Hyperparathyroidism can cause a range of symptoms, including:

• Urinating much more than usual.
• Often being thirsty.
• Tiring easily.
• Feeling weak.
• Bone and joint pain.
• Belly pain.
• Nausea, vomiting or loss of appetite.
• Constipation.
• Itchy skin.
• Depression.
• Problems concentrating.

Many people with primary hyperparathyroidism don't have symptoms. The condition often is found when a blood test that's done for another reason shows a high level of calcium in the blood.

See your healthcare professional if you have any symptoms of hyperparathyroidism. Those symptoms could be triggered by other health conditions that cause hyperparathyroidism. And some of those conditions can lead to other serious health concerns. It's important to get an accurate diagnosis of hyperparathyroidism as soon as possible, so the cause can be found and treatment can begin right away.

Hyperparathyroidism is caused by factors that raise the amount of parathyroid hormone in the blood.

When they're working correctly, the parathyroid glands help control the levels of calcium and phosphorus in the blood with parathyroid hormone.

• When there's not enough calcium in the blood, the parathyroid glands typically make more parathyroid hormone. The hormone triggers a release of calcium from the bones. It also raises the amount of calcium absorbed by the small intestine from food. The hormone lowers the amount of calcium lost in urine too. Together, these changes raise the amount of calcium in the blood.
• When there's too much calcium in the blood, the parathyroid glands typically make less parathyroid hormone, and the calcium level in the blood drops.

Calcium is best known for its role in keeping teeth and bones healthy. But calcium also helps nerve cells send signals correctly. And calcium helps keep muscles healthy. Phosphorus, another mineral controlled by parathyroid hormone, works along with calcium to keep the body healthy.

If one or more of the parathyroid glands makes a high amount of parathyroid hormone, that condition is hyperparathyroidism. There are two types of hyperparathyroidism: primary and secondary. They have different causes.

Primary hyperparathyroidism

Primary hyperparathyroidism happens because of a health issue with one or more of the parathyroid glands, including:

• A growth on a parathyroid gland that isn't cancer. This is called an adenoma. It's the most common cause of primary hyperparathyroidism.
• Two or more parathyroid glands growing larger than usual. This is called hyperplasia. It causes most of the other cases of primary hyperparathyroidism.
• A tumor that is cancer. This is a rare cause of primary hyperparathyroidism.

Secondary hyperparathyroidism

Secondary hyperparathyroidism happens because of another health condition that lowers the amount of calcium in the blood. This causes the parathyroid glands to make too much parathyroid hormone in an effort to get blood calcium back to a healthy level.

Secondary hyperparathyroidism may be caused by:

• Not enough calcium. Calcium in the body may drop to an unhealthy level if the digestive system can't absorb enough calcium from food. This often happens after surgery on the intestines, including weight loss surgery.
• Not enough vitamin D. Vitamin D helps keep the calcium level in the blood healthy. It also helps the digestive system absorb calcium from food. Sunlight helps the body make vitamin D. There's also some vitamin D in food. If you don't get enough vitamin D, the amount of calcium in the blood may drop.
• Health concerns that affect the kidneys. The kidneys take vitamin D and change it into a form that the body can use. If the kidneys don't work the way they should, the amount of vitamin D that the body can use may go down, and the calcium level drops. Kidney disease that lasts a long time, called chronic kidney disease, is the most common cause of secondary hyperparathyroidism.

In some people with secondary hyperparathyroidism that lasts a long time, the parathyroid glands get bigger. This is often due to end-stage kidney disease. The glands then begin to release parathyroid hormone when the body doesn't need it. The parathyroid hormone level doesn't go down with medical treatment, and the amount of calcium in the blood becomes too high. This is called tertiary hyperparathyroidism.

Risk factors for primary hyperparathyroidism include:

• Being a person who has gone through menopause.
• Having too little calcium or too little vitamin D in your body for a long time. These conditions are called calcium deficiency and vitamin D deficiency.
• Having a rare, inherited disorder, such as multiple endocrine neoplasia type 1, that affects the parathyroid glands.
• Having changes in certain genes that can cause hyperparathyroidism.
• Having radiation treatment on the head or neck.
• Taking the medicine lithium.

Health issues that can happen because of hyperparathyroidism, called complications, are mainly related to the long-term effects of too little calcium in the bones and too much calcium in the blood.

Common complications of hyperparathyroidism include:

• Osteoporosis. Too much parathyroid hormone in the blood causes loss of calcium from bones. That often leads to weak, brittle bones that break easily. This condition is called osteoporosis.
• Kidney stones. Too much calcium in the blood may lead to too much calcium in urine. This can cause small, hard deposits of calcium and other substances to form in the kidneys. Those deposits are called kidney stones.
• Health concerns in the heart and blood vessels. A high level of calcium in the blood is linked to some heart and blood vessel conditions, also called cardiovascular conditions. Examples include high blood pressure; a heartbeat that's too slow, called bradycardia; and a heartbeat that’s not regular, called arrhythmia.