Why is parathyroid hormone needed?
The parathyroid glands are four small glands located next to the thyroid gland. They secrete parathyroid hormone, which raises calcium levels in the blood in three ways: it releases calcium from bones, enhances its reabsorption in the kidneys, and helps convert vitamin D into an active form that improves calcium absorption in the intestines. At the same time, the hormone promotes the excretion of phosphorus. When there is little parathyroid hormone, all these mechanisms weaken: calcium decreases, phosphorus accumulates, and nerve cells become overexcitable.
- Four glands next to the thyroid
- Parathyroid hormone raises blood calcium
- Activates vitamin D in the kidneys
- Promotes phosphorus removal
- With a deficiency, calcium falls, phosphorus rises
Reasons
The vast majority of cases are associated with operations in the neck: when the thyroid gland or part thereof is removed, the parathyroid glands may be removed, damaged or deprived of blood supply. This form is sometimes temporary and goes away in weeks or months, but can remain permanent. Less commonly, the cause is autoimmune damage to the glands, often in combination with other endocrine disorders. There are congenital forms that appear from childhood. Separately, there is a pronounced deficiency of magnesium: without it, parathyroid hormone does not work, and calcium drops even with preserved glands.
- Surgeries on the thyroid and parathyroid glands
- Autoimmune disease of the glands
- Congenital and genetic forms
- Irradiation of the neck area
- Severe magnesium deficiency
- Deposition of iron or copper in systemic diseases
Symptoms
Tingling and numbness usually appear first around the mouth and in the tips of the fingers and toes. Then muscle twitching, painful movements of the hands and feet, and a feeling of stiffness appear. With a significant decrease in calcium, spasm of the larynx with hoarseness and difficulty breathing, attacks with loss of consciousness, and interruptions in the functioning of the heart are possible. With a long course, other tissues also suffer: the skin becomes dry, nails become brittle, hair thins, in children the formation of tooth enamel is disrupted, and over time, cataracts and calcium deposits in the brain tissue are possible.
- Tingling around the mouth and in the fingers
- Abduction of hands and feet, muscle spasms
- Facial muscle twitching
- Hoarseness and spasm of the larynx in severe forms
- Anxiety, fatigue, decreased concentration
- Dry skin, brittle nails, enamel damage in children
- Long term cataract
Diagnostics
The diagnosis is based on a combination of low blood calcium with low or inadequately normal parathyroid hormone. Be sure to evaluate the level of phosphorus, magnesium and vitamin D, as well as kidney function, because other conditions give a similar picture. The doctor takes into account your history of neck surgery and when symptoms began. Additionally, an ECG is prescribed, since low calcium changes the conductivity of the heart, and a study of calcium in daily urine, which is necessary for the safe selection of treatment. If a congenital form is suspected, genetic testing is possible.
- Blood calcium, preferably with albumin assessment
- Parathyroid hormone
- Phosphorus and magnesium
- Vitamin D and kidney function
- Daily urine calcium
- ECG
- Examination by an ophthalmologist to rule out cataracts
Treatment and control
The goal of treatment is not to achieve ideal numbers, but to eliminate symptoms and keep calcium at the lower end of normal without overloading the kidneys. For this purpose, calcium supplements and active forms of vitamin D are prescribed, which do not require the participation of parathyroid hormone. If there is a deficiency of magnesium, it must be replenished, otherwise the treatment will not work. Doses are selected gradually, under the control of tests, and if your state of health changes, the regimen is revised. The danger is not only low, but also too high calcium, so you cannot increase the dose yourself. In case of acute calcium deficiency with convulsions, calcium is administered intravenously in the hospital.
- Calcium supplements as prescribed by a doctor
- Active forms of vitamin D
- Replenishment of magnesium in case of its deficiency
- Calcium, phosphorus and creatinine control according to schedule
- Assessment of calcium in daily urine
- Intravenous calcium for acute symptoms
- Regular examinations by an endocrinologist and ophthalmologist