Hypoparathyroidism

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at March 15, 2016
StartDiseasesHypoparathyroidism

Hypoparathyroidism is an endocrine disease involving the parathyroid glands. The glands fail to produce enough parathyroid hormone, also known as PTH. The PTH hormone is essential for the body to maintain the proper balance of calcium and phosphorous.

Contents

Definition & Facts

Hypoparathyroidism is a very rare condition. Individuals with hypoparathyroidism have abnormally low levels of calcium in their blood and bones and elevated serum phosphorous levels. Those most at risk of developing the condition include individuals who have had recent neck surgery involving the thyroid and those with a family history of the condition. Certain autoimmune diseases and endocrine diseases such as Addison’s disease, also increase the risk of hypoparathyroidism.

Unborn babies of women with abnormally high blood calcium are at risk for chronic parathyroid suppression. If left untreated, hypoparathyroidism can cause severe complications, including painful muscle spasms, convulsions, delayed mental development, heart problems, teeth malformations, and stunted growth. Prompt diagnosis and treatment can prevent the development of these complications; however, the effects of certain complications are irreversible.

Symptoms & Complaints

The most common symptoms of hypoparathyroidism include:

Anyone experiencing these symptoms should seek medical attention as soon as possible to prevent serious complications, including seizures, difficulty breathing, and cardiac arrhythmias.

Causes

A person develops hypoparathyroidism when the parathyroid glands do not produce sufficient PTH or the hormone produced does not function properly. The parathyroid glands consist of four tiny glands located on the posterior side of the thyroid gland. Each gland is roughly the size of a grain of rice.

Hypoparathyroidism is rare since all four of the of the parathyroid glands would have to be affected in order for a person to develop the low blood calcium levels associated with the condition. Most cases of hypoparathyroidism occur when the parathyroid glands are damaged or removed during surgery to treat thyroid problems, neck cancer, or throat cancer.

Certain autoimmune diseases can cause the body to create antibodies that attack the parathyroid tissue. As a result, the glands stop producing the PTH hormone. Individuals may be born with hereditary hypoparathyroidism in which the glands are either missing or not functioning from birth. In cases where the disorder runs in the family, the disorder is typically linked to a recessive trait. Cancer radiation treatments involving the neck or face may destroy the parathyroid glands.

Abnormally low magnesium levels may also lead to the development of hypoparathyroidism since magnesium is required for the glands to secrete the PTH hormone. An overload of certain metals, including iron and copper can contribute to hyperparathyroidism. Patients undergoing hemodialysis for end-stage kidney disease may develop aluminum deposits within the parathyroid glands leading to primary hypoparathyroidism.

Diagnosis & Tests

The first step in diagnosing hypoparathyroidism is a thorough patient history. The doctor will focus on symptoms, such as muscle cramps and paresthesia, as well as any history of neck surgery. This is followed by a physical examination in which the doctor will look for signs such as dry skin, facial twitching, and brittle nails.

If the preliminary examination suggests hypoparathyroidism, the doctor may order blood tests to confirm the diagnosis. These tests look for low blood calcium levels, high blood phosphorous levels, low magnesium levels, and a low level of PTH hormone. A urine test may also be ordered to determine if the body is excreting excess calcium in the urine.

If the patient is a young child, the doctor will likely order tests to ensure that the child’s mental and physical development in on track and that the teeth are forming properly. If hypoparathyroidism is detected and treated early, the child can expect to grow and develop normally and lead a normal, healthy life.

Treatment & Therapy

The purpose of hypoparathyroidism treatment is to help the body maintain normal calcium and phosphorous levels. The treatment regimen typically involves:

  • Oral calcium carbonate tablets—These tablets help increase blood calcium levels. Some patients do experience constipation and other gastrointestinal side effects when taking high doses of calcium supplements.
  • Vitamin D—This vitamin, typically given in the form of calcitriol, promotes calcium absorption and helps the body eliminate phosphorous.
  • Thiazide diuretics—If a patient’s blood calcium levels remain too low while taking oral supplements, the doctor may add a thiazide diuretic, such as metolazone or hydrochlorothiazide, which can help increase blood calcium levels.

A synthetic version of parathyroid hormone, currently being used to treat osteoporosis, is being studied as a possible treatment for hypoparathyroidism; however, it has not been approved by the Food and Drug Administration at this time. If a patient is experiencing severe muscle spasms, also known as tetany, the doctor may order intravenous calcium infusions.

Since hypoparathyroidism is a life-long condition, the individuals will need to have regular blood tests to measure blood calcium and phosphorous levels. In the beginning, these tests may be performed monthly or even weekly. The frequency may decrease to twice a year as long as the condition remains well-controlled.

Individuals with hypoparathyroidism should eat a diet that is rich in calcium, including dairy, fortified juices and cereals, and green leafy vegetables. They should also avoid carbonated beverages, eggs, and meats, which are high in phosphorous. Most people with hypoparathyroidism are able to manage symptoms and maintain healthy calcium and phosphorous levels as long as the adhere to their treatment regimen.

Prevention & Prophylaxis

There is no way to specifically prevent hypoparathyroidism. Individuals who undergo neck or thyroid surgery, radiation treatment of the face or neck, or who have autoimmune conditions, should be aware of the symptoms of hypoparathyroidism and see their doctor immediately if they should occur. Individuals with the condition should be under the care of an endocrinologist so that symptoms can be monitored and managed.