Hyperparathyroidism - Types, Causes, Symptoms, and Treatment

Introduction:

Parathyroid glands are four pea-sized glands located in the neck behind the thyroid gland, two on each side. Parathyroid glands secrete a hormone called parathyroid hormone (PTH) or parathormone, which is responsible for regulating calcium, phosphorus, and vitamin D levels in the blood. Calcium is an essential mineral with a regulatory system that is monitored by the parathyroid glands. Calcium is not only responsible for bone health but also plays a vital role in the functioning of the heart, muscles, and nerves.

What Is Hyperparathyroidism?

Hyperparathyroidism is a disorder in which the parathyroid glands become overactive and secrete an excess of parathyroid hormone (PTH), leading to increased calcium levels in the blood which is known as hypercalcemia.

What Is the Role of Calcium in the Body?

The following are the functions of calcium in the body:

• Formation of solid bones and teeth.

• Channel for transmission of impulses along nerves.

• Maintenance of regular rhythmic activity of the heart.

• Muscle contraction.

• Formation of blood clots.

The average intake required for normal body functioning is 1000 to 1500 milligrams of calcium

per day.

What Are the Types of Hyperparathyroidism?

There are three types of hyperparathyroidism, namely primary, secondary, and tertiary.

• Primary Hyperparathyroidism: Primary hyperparathyroidism occurs due to the overactivity of one or more parathyroid glands which leads to excess secretion of parathyroid hormone (PTH). Sometimes, the symptoms of primary hyperparathyroidism can be really obvious like the presence of kidney stones, frequent headaches, depression, fatigue, and fast heartbeat (atrial fibrillation).

• Secondary Hyperparathyroidism: Secondary hyperparathyroidism occurs due to a decrease in blood calcium levels caused by underlying conditions and not due to an overactive parathyroid gland.

• Tertiary Hyperparathyroidism: Tertiary hyperparathyroidism is when the glands keep producing excess PTH even after the blood calcium levels have reached normal levels. Patients with kidney disorders may have tertiary hyperparathyroidism.

What Are the Causes of Hyperparathyroidism?

Causes of primary hyperparathyroidism include:

• A benign (harmless) growth called adenoma on one of the glands is the most common cause.

• Enlargement of two or more parathyroid glands that causes a release of excessive parathyroid hormone.

• Cancer of the parathyroid glands (a rare occurrence).

Causes of secondary hyperparathyroidism include:

• Chronic Kidney Disease: This is the most common cause of secondary hyperparathyroidism. Kidneys help the body convert vitamin D into a more usable form. Long-term kidney disease affects the functioning of vitamin D, thereby leading to calcium deficiency.

• Calcium Deficiency: Severe calcium deficiency occurs due to the inability of the body to absorb calcium from food or if there is an increase in the amount of calcium excreted.

• Vitamin D Deficiency: The body receives vitamin D when exposed to sunlight and also through diet. It helps the body absorb calcium from the intestines. The deficiency of vitamin D leads to a calcium deficit in the blood, thereby causing the parathyroids to secrete excess PTH.

What Are the Risk Factors for Hyperparathyroidism?

• A person is at increased risk for hyperparathyroidism in the following cases:

• A female who has gone through menopause.

• A calcium or vitamin D deficiency that has been present for a long time.

• Radiation therapy for the treatment of neck cancer.

• An inherited disorder called multiple endocrine neoplasia type 1 is a condition that causes multiple tumors in the pituitary, parathyroid glands, and pancreas.

• Lithium therapy used for the treatment of bipolar disorder (a serious mental illness that causes mood swings).

What Are the Symptoms of Hyperparathyroidism?

Hyperparathyroidism is diagnosed through blood tests before any visible symptoms occur. Symptoms start to appear when the condition has progressed and starts showing effects on various other body functions. There is a dysfunction of the other tissues or organs due to increased calcium levels in blood and loss of calcium from bones.

The symptoms that occur in hyperparathyroidism include:

• Kidney stones.

• Osteoporosis (a condition in which the bones become weak and tend to fracture easily).

• Pain in the abdomen.

• Excessive urination.

• Nausea and vomiting.

• Lack of appetite.

• Fatigue.

• Memory loss.

• Depression.

• High blood pressure.

Parathyroid disease and hyperparathyroidism are linked with weight gain.

What Are the Complications of Hyperparathyroidism?

Long-term effects that occur due to too little calcium in the bones and too much calcium in the blood include:

• Bones become weak and tend to fracture.

• High blood pressure leading to heart disease.

• Chronic kidney disease.

• Neonatal hypoparathyroidism (a condition in newborn babies who have very low levels of parathyroid hormone due to untreated hyperparathyroidism in pregnant mothers).

How Is Hyperparathyroidism Diagnosed?

The doctors advise specific diagnostic tests after they take the medical history and perform a physical examination. These tests help to know the cause of the condition. The following diagnostic tests are advised by the doctor, which includes:

• Blood Tests: Blood tests are used to determine the levels of calcium, phosphorus, vitamin D, and parathyroid hormone.

• Bone Mineral Density Test: This test is used to determine the bone loss that occurs due to hyperparathyroidism. The most common test that measures bone mineral density is dual-energy X-ray absorptiometry (DEXA).

• Urine Test: A 24-hour urine test is done to determine the calcium levels in urine over 24 hours. This test helps assess the severity of hyperparathyroidism or helps to know about an underlying kidney disease that could be causing the symptoms. If the calcium levels in urine are not too high, then the condition may not require treatment.

• Imaging Tests: The doctor may order X-rays or an ultrasound scan of the abdomen to detect kidney stones or any underlying kidney disorders.

• Sestamibi Parathyroid Scan: Overactive parathyroid glands absorb a radioactive compound called sestamibi. The doctors use a scanner to detect the radioactivity due to absorbed sestamibi. Apart from the parathyroid glands, the thyroid also can absorb sestamibi. Iodine is used to prevent the uptake by the thyroid gland. Therefore, the thyroid gets masked digitally, revealing the uptake of sestamibi by the parathyroids.

• Computerized Tomography (CT) Scan: A combination of CT scan and sestamibi scan may help detect the abnormality more clearly.

What Are the Treatment Options for Hyperparathyroidism?

Treatment for hyperparathyroidism can include a wait-and-watch approach, medications, or surgery.

Wait and Watch Approach:

The doctors recommend waiting before starting any treatment in cases where:

• The blood calcium levels are only slightly above normal.

• There are no kidney stones or kidney problems.

• Bone mineral density tests are almost normal or slightly below normal.

• The patient may need regular monitoring periodically to keep a check on the values.

Medications:

Medicines used for the treatment are:

• Calcimimetics: These drugs mimic the calcium circulating in the bloodstream and increase the blood calcium levels confusing the overactive parathyroids thereby resulting in lesser production of PTH.

• Hormone Replacement: Therapy gives good results in women with osteoporosis or those undergoing menopause. However, it does not solve the underlying problem with parathyroids. Headaches, tender breasts, and dizziness are the side effects noted in this therapy.

• Bisphosphonates: They work by preventing calcium loss from the bones and decreasing the chances of osteoporosis.

Surgery:

Surgery is done to remove the enlarged glands. It is an outpatient procedure where the patient receives local anesthesia and minor cuts (incisions) are made on the neck. Damage to the vocal cords and long-term low blood calcium levels are possible risks of surgery.

Lifestyle Changes:

Certain lifestyle changes improve the quality of life in patients with hyperparathyroidism. They include:

• Monitoring of blood calcium and vitamin D levels.

• Regular exercise to strengthen the bones and muscles.

• Drinking sufficient amounts of fluids to prevent the formation of kidney stones.

• Avoiding medicines that increase the levels of calcium (diuretics and lithium).

• Quitting smoking as it harms bone health.

Conclusion:

Parathyroid glands are one of the essential glands that secrete parathormone, which regulates calcium levels in the body. As calcium levels determine nerve, muscle, heart, bone, and brain health, the PTH levels need regular monitoring. A healthy diet, regular exercise, and follow-ups with the doctor play a pivotal role in maintaining good health. Hyperparathyroidism can be managed well in most cases with the help of medicines, lifestyle changes, and regular doctor check-ups. If surgery is advised, the doctor will recommend testing the calcium and PTH levels every six to eight weeks, followed by a yearly check-up.