Hypoparathyroidism

概述

Hypoparathyroidism is an uncommon condition in which your body produces abnormally low levels of parathyroid hormone (PTH). PTH is key to regulating and maintaining a balance of two minerals in your body — calcium and phosphorus.

The low production of PTH in hypoparathyroidism leads to abnormally low calcium levels in your blood and to an increase of phosphorus in your blood.

Supplements to normalize your calcium and phosphorus levels treat the condition. Depending on the cause of your hypoparathyroidism, you'll likely need to take supplements for life.

症状

Signs and symptoms of hypoparathyroidism can include:

• Tingling or burning in your fingertips, toes and lips
• Muscle aches or cramps in your legs, feet, stomach or face
• Twitching or spasms of your muscles, particularly around your mouth, but also in your hands, arms and throat
• Fatigue or weakness
• Painful menstrual periods
• Patchy hair loss
• Dry, coarse skin
• Brittle nails
• Depression or anxiety

When to see a doctor

If you have signs or symptoms associated with hypoparathyroidism, see your doctor for an evaluation. Contact your doctor immediately if you have a seizure or have difficulty breathing. These can both be complications of hypoparathyroidism.

病因

Hypoparathyroidism occurs when your parathyroid glands don't secrete enough parathyroid hormone. You have four small parathyroid glands in your neck behind your thyroid gland.

Factors that can cause hypoparathyroidism include:

• Neck surgery. This most common cause of hypoparathyroidism develops after accidental damage to or removal of the parathyroid glands during surgery. Neck surgery may be done to treat conditions of the thyroid gland, or to treat throat or neck cancer.
• Autoimmune disease. In some cases, your immune system attacks parathyroid tissues as if they were foreign bodies. In the process, the parathyroid glands stop producing their hormone.
• Hereditary hypoparathyroidism. In this form, either you're born without parathyroid glands or they don't work properly. Some types of hereditary hypoparathyroidism are associated with deficiencies of other hormone-producing glands.
• Low levels of magnesium in your blood. Low magnesium levels can affect the function of your parathyroid glands. Normal magnesium levels are required for normal production of parathyroid hormone.
• Extensive cancer radiation treatment of your face or neck. Radiation can result in destruction of your parathyroid glands. In rare cases, radioactive iodine treatment for hyperthyroidism may lead to hypoparathyroidism.

风险因素

Factors that can increase your risk of developing hypoparathyroidism include:

• Recent neck surgery, particularly if the thyroid was involved
• A family history of hypoparathyroidism
• Having certain autoimmune or endocrine conditions, such as Addison's disease — which causes a decrease in the hormones your adrenal glands produce

并发症

Hypoparathyroidism can result in various complications.

Reversible complications

The following are due to low calcium levels, most of which are likely to improve with treatment:

• Cramplike spasms of your hands and fingers that can be prolonged and painful, or muscle pain and twitches or spasms of the muscles of your face, throat or arms. When these spasms occur in your throat, they can interfere with breathing, creating a possible emergency.
• Tingling or burning sensations, or a pins and needles feeling, in your lips, tongue, fingers and toes.
• Seizures.
• Malformed teeth, affecting dental enamel and roots, in cases when hypoparathyroidism occurs at an early age when teeth are developing.
• Problems with kidney function.
• Heart arrhythmias and fainting, even heart failure.

Irreversible complications

Accurate diagnosis and treatment might prevent these complications associated with hypoparathyroidism. But once they occur, calcium and vitamin D won't improve them:

• Stunted growth
• Slow mental development in children
• Calcium deposits in the brain, which can cause balance problems and seizures
• Clouded vision due to cataracts

预防

There are no specific actions to prevent hypoparathyroidism. However, if you're scheduled to have thyroid or neck surgery, talk to your surgeon about the risk of damage to your parathyroid glands during the procedure. Your doctor may choose to test your calcium, parathyroid hormone and vitamin D levels and have you begin supplementation if needed before surgery.

If you've had surgery involving your thyroid or neck, watch for signs and symptoms that could indicate hypoparathyroidism, such as a tingling or burning sensation in your fingers, toes or lips, or muscle twitching or cramping. If they occur, your doctor might recommend prompt treatment with calcium and vitamin D to minimize the effects of the disorder.