How does calcium regulation work?
The parathyroid glands are four small structures on the back surface of the thyroid gland. They sense the level of calcium in the blood and, when it decreases, release parathyroid hormone, which removes calcium from the bones, enhances its reabsorption in the kidneys and activates vitamin D in the intestines. When one of the glands becomes autonomous due to an adenoma, it secretes the hormone constantly, regardless of calcium levels. Calcium increases, phosphorus decreases, bones lose mineral density, and the kidneys are forced to excrete excess calcium, which contributes to the formation of stones.
- Primary - adenoma or hyperplasia of glands
- Secondary—response to vitamin D deficiency or kidney disease
- Tertiary - autonomy of the glands after long stimulation
- Normocalcemic variant with normal calcium
- Rare hereditary syndromes affecting multiple glands
Causes and risk factors
In approximately the vast majority of cases of the primary form, a single benign adenoma is found, less often - an enlargement of several glands, and very rarely - a malignant tumor. The risk is higher in women after menopause and in people over fifty years of age, as well as those who have had previous radiation exposure to the neck area. The secondary form develops with chronic kidney disease, when the activation of vitamin D is impaired and phosphorus is retained, as well as with prolonged severe vitamin D deficiency and impaired absorption in the intestine. Hereditary syndromes of multiple endocrine tumors are uncommon, but require examination of relatives.
- Parathyroid adenoma
- Hyperplasia of several glands
- Chronic kidney disease
- Vitamin D deficiency
- Malabsorption in the intestines
- History of irradiation of the neck area
- Hereditary endocrine syndromes
Symptoms
For a long time the disease proceeds hidden. When complaints appear, they are nonspecific: fatigue, muscle weakness, depression, memory loss, thirst and frequent urination, constipation, nausea, pain in bones and joints. On the part of the kidneys, colic and re-formation of stones occur. The bones suffer unnoticed until a fracture of the forearm, hip or vertebra occurs due to a minor injury. Some people develop peptic ulcers or pancreatitis. Very high calcium levels cause confusion and require emergency treatment.
- Weakness, fatigue, depressed mood
- Thirst and frequent urination
- Kidney stones, renal colic
- Bone pain, fractures due to minor trauma
- Constipation, nausea, abdominal pain
- Decreased memory and concentration
Diagnostics
The diagnosis is made by a combination of elevated blood calcium and elevated or inadequately normal parathyroid hormone. Be sure to evaluate the level of vitamin D, because its deficiency itself increases parathyroid hormone, and phosphorus, which is reduced in the primary form. Calcium in daily urine and kidney function are determined. To find the altered gland before surgery, ultrasound of the neck and radioisotope study are used. The condition of the bones is assessed by densitometry, the condition of the kidneys is assessed by ultrasound to look for stones and calcifications.
- Calcium total and ionized
- Parathyroid hormone
- Phosphorus and alkaline phosphatase
- Vitamin D and creatinine
- Daily urine calcium
- Ultrasound of the neck and radioisotope study
- Densitometry and ultrasound of the kidneys
Treatment
In primary hyperparathyroidism, the only radical method is surgical removal of the altered gland. Surgery is recommended for severely elevated calcium levels, kidney stones, decreased bone density, impaired renal function, and at a young age. If there are no indications for surgery, choose observation with regular monitoring of calcium, kidney function and densitometry, ensure sufficient drinking and normal levels of vitamin D. In the secondary form, treat the underlying disease: replenish vitamin D, control phosphorus and calcium in kidney disease, and, if necessary, use drugs that reduce the production of parathyroid hormone.
- Surgical removal of adenoma
- Monitoring with calcium monitoring and densitometry
- Sufficient drinking regime
- Correction of vitamin D deficiency under medical supervision
- Treatment of chronic kidney disease
- Drugs that reduce parathyroid hormone, as prescribed by a doctor
- Calcium control after surgery