Signs and symptoms of hypoparathyroidism can include:
- Tingling or burning (paresthesias) in your fingertips, toes and lips
- Muscle aches or cramps affecting your legs, feet, abdomen or face
- Twitching or spasms of your muscles, particularly around your mouth, but also in your hands, arms and throat
- Fatigue or weakness
- Painful menstruation
- Patchy hair loss, such as thinning of your eyebrows
- Dry, coarse skin
- Brittle nails
- Depression, mood swings
- Memory problems
When to see a doctor
If you have any of the signs and symptoms associated with hypoparathyroidism, make an appointment with your doctor for an evaluation. Contact your doctor immediately if you have a seizure or have difficulty breathing, both of which can be complications of hypoparathyroidism.
Hypoparathyroidism occurs when your parathyroid glands don't secrete enough parathyroid hormone. You have four parathyroid glands — each normally about the size of a grain of rice — situated in your neck, adjacent to your thyroid gland.
The low production of PTH leads to abnormally low calcium levels (hypocalcemia) in your blood and bones and to increased levels of serum phosphorus (hyperphosphatemia).
Factors that can cause hypoparathyroidism include:
- Acquired hypoparathyroidism. This most common cause of hypoparathyroidism develops after accidental damage to or removal of the parathyroid glands during surgery. This surgery may be a treatment for diseases of the nearby thyroid gland, or for throat cancer or neck cancer. Today, surgeons are more careful to avoid injuring the parathyroid glands during surgery.
- Autoimmune disease. In this condition, your immune system creates antibodies against the parathyroid tissues, trying to reject them as if they were foreign bodies. In the process, the parathyroid glands stop manufacturing their hormone.
- Hereditary hypoparathyroidism. In this form, either the parathyroid glands aren't present at birth, or they don't work properly. Some types of hereditary hypoparathyroidism are associated with deficiencies of other hormone-producing glands.
- Extensive cancer radiation treatment of your face or neck. Radiation can result in destruction of your parathyroid glands, as can radioactive iodine treatment for hyperthyroidism, occasionally.
- Low levels of magnesium in your blood, which can affect the function of your parathyroid glands. Normal serum magnesium levels are required for optimum secretion of parathyroid hormone.
Factors that may 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 — a condition characterized by a deficit in hormone production by the adrenal glands
Hypoparathyroidism may result in numerous complications.
The following complications are due to low calcium levels, most of which are likely to improve with adequate treatment:
- Tetany. These cramp-like spasms of your hands and fingers may be prolonged and painful. Tetany may also include muscle discomfort 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 potential emergency.
- Paresthesias. These are characterized by sensory symptoms of odd, tingling sensations or pins and needles feelings in your lips, tongue, fingers and feet.
- Loss of consciousness with convulsions (grand mal seizures).
- Malformation of the teeth, affecting dental enamel and roots.
- Impaired kidney function.
- Heart arrhythmias and fainting, even heart failure.
Accurate diagnosis and effective treatment may prevent these complications associated with hypoparathyroidism, but once present, they won't improve with calcium and vitamin D treatment:
- Stunted growth (short stature)
- Slow mental development (or mental retardation) in children
- Calcium deposits in the brain, which can cause balance problems and seizures
There are no specific actions you can take to prevent hypoparathyroidism. However, if you're scheduled to have thyroid or neck surgery, talk to your surgeon for assurance that steps will be taken to avoid damage to your parathyroid glands during the procedure.
If you've had surgery involving your thyroid or neck, be alert 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. When they occur, your doctor may recommend prompt treatment with calcium and vitamin D to minimize the effects of the disorder.