Parathyroid Surgery Part 2: Understanding the Parathyroid Glands

Back view of thyroid gland showing four small parathyroid glands near bottom of thyroid.

Normal parathyroid glands

The parathyroid glands are usually no bigger than grains of rice. Their main job is to keep the level of calcium in the blood within a certain range. Keeping a normal level of calcium helps the muscles and nerves work properly and also keeps bones strong. When there is a problem with the parathyroid glands, the blood calcium level may get too high. This has effects throughout the body.

The Parathyroid Glands

The parathyroid glands are most often found behind the thyroid gland in the neck. The exact locations can vary with each person. The parathyroid glands control the level of calcium in the blood. They do this by making parathyroid hormone (PTH). This is a chemical messenger that tells the body how to control calcium.

How These Glands Work

When the blood calcium level is low, the glands make more PTH. This tells the body to increase the amount of calcium in the blood. To increase the blood calcium level, the body may absorb more calcium from food in the intestines. It may also take calcium from the bones. When the blood calcium level is high, the glands make less PTH. This tells the body to decrease the amount of calcium in the blood. To decrease the blood calcium level, calcium is filtered out of the blood by the kidneys.

Enlarged parathyroid gland

Enlarged parathyroid gland

When You Have Hyperparathyroidism

With hyperparathyroidism, one or more of the parathyroid glands become larger. It then makes too much PTH. As a result, the body continues to increase the level of calcium in the blood. This causes a condition called hypercalcemia (an above-normal level of blood calcium). Hypercalcemia can lead to a number of problems throughout the body. These are listen below.

Nervous system problems. A high blood calcium level can make you feel tired, depressed, or irritable. You may also have problems with concentration or memory.

Muscle problems. A high blood calcium level can affect the muscles, causing muscle weakness and pain.

Kidney problems. As extra calcium passes through the kidneys, you may have frequent urination. And, you’re more likely to develop kidney stones and kidney disease.

Digestive problems. The intestines absorb calcium to be used by the body. A high blood calcium level can cause abdominal pain, nausea, vomiting, and constipation. Over time, you may even develop stomach ulcers or pancreatitis.

Bone and joint problems. To increase blood calcium, calcium may be taken from bones. This can cause bone pain and make fractures and bone disease more likely.