What is hypoparathyroidism?

Hypoparathyroidism is a rare disease caused by an absent or low level of PTH (parathyroid hormone) in the body1. PTH is produced in the parathyroid glands of your neck, and it plays an important role in maintaining your body’s mineral balance (calcium and phosphate).2,3



Sites of PTH action

Kidneys

PTH tells your kidneys to keep calcium and remove phosphate

Gut

PTH activates vitamin D that helps your body absorb calcium in the gut

Bones

PTH helps your bones release calcium

If your body is not able to produce enough PTH, your blood calcium levels may be too low and your phosphate blood levels too high.2,3



How common is hypoparathyroidism?

Information on the prevalence of hypoparathyroidism is limited, but recent estimates are:

  • 24 per 100,000 inhabitants in Denmark1,4,5
  • 10.2 per 100,000 inhabitants in Norway6
  • 25-37 per 100,000 population in the US6-8

Causes

Let’s look at the causes and symptoms to help you understand why this rare condition occurs.

Surgery

Most common cause of acquired hypoparathyroidism

In most cases, patients with chronic hypoparathyroidism have had thyroid surgery (approximately 75% of cases).3,8,9

Any of the following surgeries can result in parathyroid damage:

  • Surgery on or the total removal of the thyroid or parathyroid glands
  • Surgery on structures near the parathyroid glands
  • Surgery to remove cancer in the neck

If you have had thyroid surgery, your doctor may test your blood calcium and PTH levels after surgery. If your levels have not returned to normal after 6 months, you may have chronic hypoparathyroidism.1,3

Autoimmunity

Second most common cause
in adults

Autoimmune hypoparathyroidism can occur alone or as part of a condition involving multiple autoimmune disorders associated with the endocrine glands.1

Radiation

Very rare cause

Radiation treatment for cancer of the head or neck (or radioactive iodine treatment for hyperthyroidism) can damage the parathyroid glands.

Heredity

Very rare cause

In two case reports, hypoparathyroidism was found to occur when cancer cells spread to the parathyroid glands.

Unknown

Very rare cause

Some cases of hypoparathyroidism appear due to unknown causes. Doctors refer to such conditions as “idiopathic.”

Signs and symptoms

Hypoparathyroidism may cause a wide range of symptoms that can be divided into three categories: physical, cognitive and emotional.9

Symptoms experienced by patients with chronic hypoparathyroidism

PHYSICAL SYMPTOMS

  • Fatigue
  • Muscle pain/cramps
  • Pins and needles (Paraesthesia)
  • Muscle spasm (Tetany)
  • Joint or bone pain
  • Pain/heaviness/weakness in hands and feet
  • Disturbance to bowel movements
  • Brittle nails
  • Heat intolerance
  • Headaches
  • Damage to skin/extreme dry skin
  • Cold sensations
  • Hair loss
  • Nausea

Cognitive Symptoms

  • “Brain fog”/mental lethargy
  • Inability to focus
  • Memory loss/forgetfulness
  • Sleep disturbance
  • Inability to think through a complicated task/multitask

Emotional Symptoms

  • Anxiety/fear
  • Feeling sad
  • Emotional sensitivities
  • Feeling misunderstood
  • Hyperirritability/being hypercritical
  • Social withdrawal/feeling isolated

How it is diagnosed

While taking into consideration your symptoms, past neck surgery and family history: 1,13

Physical

Your doctor may test you for signs and symptoms of hypocalcaemia.

Stethoscope
Blood Tests

Your doctor may ask you to get a blood test to check your levels of calcium, phosphate, magnesium, vitamin D and parathyroid hormone.

Test Tube
Urine Test

Your doctor may test your calcium levels in the urine to see how well your kidneys are working.

Beaker

If tests show that you have low levels of calcium in your blood and/or absent or low levels of PTH, hypoparathyroidism could be the cause of your hypocalcaemia.1