Hypoparathyroidism occurs when the parathyroid glands do not make enough parathyroid hormone. Behind the thyroid gland are four small parathyroid glands in the neck. Parathyroid hormone controls calcium and phosphorus levels, so too little parathyroid hormone can cause abnormal calcium and phosphorus levels. Hypoparathyroidism is an uncommon condition that occurs when the parathyroid glands in the neck do not produce enough parathyroid hormone (PTH).
Each has four parathyroid glands located near or behind the thyroid gland. Each gland is the size of a rice grain. The main function of PTH is to regulate calcium levels in your body. It also regulates phosphorus levels and has a role in the production of the active form of vitamin D. All these activities are necessary to maintain calcium balance. Your body uses calcium to help your nerves, muscles, and heart function. Low calcium levels can result in symptoms ranging from mild to severe muscle spasms, tremors, heart problems, and seizures.
Signs and symptoms
Symptoms of hypoparathyroidism are usually related to low levels of calcium in the blood. Signs and symptoms may include:
- Burning or stinging of fingers, toes, and lips
- Muscle aches or pains in the legs, feet, stomach, or face
- Muscle twitching or spasms, especially around the mouth, but also in the hands, arms, and throat
- Fatigue or weakness.
Other signs and symptoms associated with hypoparathyroidism include:
- Painful menstruation.
- Complex hair loss
- Dry, rough skin
- Broken nails
- Depression or anxiety
What is the difference between hypoparathyroidism and hyperparathyroidism?
In the medical world, the prefix “hyper-” means “too much” or “high.” The prefix “hypo-” means “not enough” or “less.” Hypoparathyroidism occurs when your parathyroid glands do not secrete enough parathyroid hormone (PTH), and hyperparathyroidism occurs when your parathyroid glands make too much PTH.
Because your parathyroid glands are responsible for controlling the amount of calcium in your blood, too much PTH causes too much calcium in your blood, and too little PTH causes not enough calcium.
Causes
Hypoparathyroidism occurs when the parathyroid glands do not make enough parathyroid hormone. But behind the thyroid gland are four small parathyroid glands in the neck.
Parathyroid hormone regulates calcium and phosphorus levels, so too little parathyroid hormone can cause abnormal levels of:
- Calcium. This mineral accumulates in the bones and teeth, making them hard. Calcium is also essential for muscle function, proper nerve and brain function, and regulation of heart rhythm and blood pressure.
- Phosphorus. This mineral is found in all cells, but mostly in bones. The body needs phosphorus to make energy from food. Phosphorus also helps in muscle, nerve, heart, and kidney function.
Causes of hypoparathyroidism may include:
- Neck surgery. The most common cause of hypoparathyroidism. It develops after the parathyroid gland is accidentally damaged or removed during surgery. Neck surgery may be performed to treat thyroid gland conditions, or to treat throat or neck cancer.
- Autoimmune disease. In some cases, the immune system attacks the parathyroid tissues as if they were foreign bodies. In this process, the parathyroid glands stop making their own hormones.
- Hereditary hypoparathyroidism. This form can result from either being born without a parathyroid gland or with glands that do not function properly. Some forms of hereditary hypoparathyroidism are associated with a deficiency of other hormone-producing glands.
- Low levels of magnesium in the blood. Low magnesium levels can affect the function of the parathyroid gland. Normal production of parathyroid hormone requires normal magnesium levels.
- Extensive radiation treatment for the face or neck cancer. Radiation can damage the parathyroid glands. In rare cases, radioactive iodine treatment for hyperthyroidism can cause hypoparathyroidism.
Diagnosis of hypoparathyroidism
Your doctor may start by taking your medical history. They will then perform a physical exam to check for symptoms such as dry skin, muscle spasms, and hair loss.
Your doctor will order blood tests to check your blood levels of:
- Calcium
- Phosphorus
- Magnesium
- PTH
Additional tests include the following:
- Your doctor may test your urine for calcium to determine if excess calcium is being excreted in the urine.
- An electrocardiogram is a test that measures the electrical activity in your heart. Information from this test can tell your doctor if you have an abnormal heart rhythm, which could be caused by a lack of calcium.
- X-rays and bone density tests can help your doctor determine if low levels of calcium have affected your bones.
Doctors will also check for abnormal tooth development and delayed milestones to diagnose the condition in children.
Treatment
The goal of treatment is to relieve symptoms and return calcium and phosphorus levels in your body to a normal range.
Treatment usually includes:
- Oral calcium. Oral calcium supplements — such as tablets, chewable, or liquids — can increase calcium levels in your blood. However, in high doses, calcium supplements can cause digestive side effects, such a+s constipation, in some people.
- Vitamin D. High amounts of vitamin D, usually in the form of calcitriol, can help your body absorb calcium and eliminate phosphorus. Calcitriol is a prescription from your healthcare provider for active vitamin D. It’s different from normal supplements that you can get without a prescription.
- Magnesium. If your magnesium levels are low and you are experiencing symptoms of hypoparathyroidism, you may need to take a magnesium supplement.
- Thiazide diuretics. If your calcium levels remain low despite treatment, or if your urine contains too much calcium, thiazide diuretics can help reduce the amount of calcium you lose through your urine.
- Parathyroid hormone replacement. The US Food and Drug Administration (FDA) has approved parathyroid hormone (Natpara) for the treatment of low blood calcium due to hypoparathyroidism. This is a once-daily injection. Because of the potential risk of bone cancer (osteosarcoma), a risk seen in animal studies, this drug is available only through a limited program. The program restricts use to people whose calcium levels cannot be controlled with calcium and vitamin D supplements and who understand the risks.
Diet
Your health care provider may recommend that you consult a registered dietitian, who will likely recommend a diet that:
- Rich in calcium. This includes dairy products, green leafy vegetables, broccoli, and foods with extra calcium, such as orange juice and breakfast cereals.
- Low in phosphorus. This means avoiding carbonated soft drinks, which contain phosphorus in the form of phosphoric acid and limiting processed foods, meat, hard cheese, nuts, and whole grains.
Intravenous administration
If you need immediate relief of symptoms, you may need to stay in the hospital to receive calcium through a small tube in a vein in your hand or arm (intravenously). You will also take oral vitamin D tablets. After you leave the hospital, you will continue to take calcium and vitamin D tablets.