All There is to Know About Hyperparathyroidism
Hyperparathyroidism is a condition in which the parathyroid glands become overactive and begin to secrete too much parathyroid hormone.
In this article, we explore all you need to know about hyperparathyroidism, including its signs and symptoms, causes and how to treat it.
What is Hyperparathyroidism?
Hyperparathyroidism is a condition which affects the parathyroid glands. These are four small glands which are in the neck. The parathyroid glands are very tiny; just 3 to 4mm in diameter. This is around the same size as a grain of rice. Their function is to secrete a hormone known as parathyroid hormone, or PTH.
The role of PTH is to control calcium levels in the body. Most people know that calcium is needed for strong bones and teeth. However, it is also necessary for the nervous system to function properly, as well as heart and kidney health.
If calcium levels in the body get too low, the parathyroid glands produce PTH. This hormone raises calcium levels in three different ways:
- Releasing calcium that is stored in bones
- Increasing calcium absorption from food
- Allowing the kidneys to hold onto calcium that would otherwise be excreted in urine
If calcium levels are normal or too high, the parathyroid glands stop releasing PTH. However, in hyperparathyroidism, they continue to release this hormone regardless, causing excess calcium to build up in the body.
Signs and Symptoms of Hyperparathyroidism
In some cases, hyperparathyroidism may cause no symptoms at all. However, some people will experience the following hyperparathyroidism symptoms:
- Muscle weakness
- Frequent urination
- Nausea or vomiting
- Appetite loss
- Abdominal pain
- Poor concentration
If left untreated, hyperparathyroidism could cause:
- Severe dehydration
- Bone and joint pain
- Irregular heartbeat
- High blood pressure
Clinical signs of parathyroid can usually be detected by blood and urine tests. These may show raised PTH and calcium levels. A scan known as a DEXA scan may be used to see whether the body is breaking down bone too fast.
Hyperparathyroidism and Hypercalcemia
Many of the symptoms of Hyperparathyroidism are due to hypercalcemia, or too much calcium in the blood. Doctors may diagnose hypercalcemia if your blood serum level is over 2.6mmol/L.
Hypercalcemia can cause several long-term complications for people with hyperparathyroidism. These include the following:
- Osteoporosis (brittle bones) and increased risk of fractures
- Kidney stones
- Peptic ulcers
In severe cases, it can lead to kidney failure, coma and death.
Causes of Hyperparathyroidism
Hyperparathyroidism can be primary or secondary. Primary hyperthyroidism (PHPT) is caused by a problem with the parathyroid glands themselves. Secondary hyperparathyroidism (SHPT) is caused by issues elsewhere in the body.
Primary Hyperparathyroidism (PHPT)
The most common causes of PHPT include:
- A benign (non-cancerous) tumour known as an adenoma
- Hyperplasia (swelling) of the parathyroid glands
In some cases, hyperparathyroidism can be a result of cancer, although this is more unusual.
Secondary Hyperparathyroidism (SHPT)
Some common causes of SHPT include:
- Kidney failure
- Vitamin D deficiency
Hyperparathyroidism is most common in women who have already gone through menopause. Women are twice as likely to be affected by hyperparathyroidism than men.
Other risk factors include certain genetic disorders, exposure to high doses of radiation and medication such as lithium.
The most appropriate hyperparathyroidism treatment will depend on whether the condition is primary or secondary.
For PHPT, the most common treatment is to remove the affected glands. Since there are four parathyroid glands, three may be removed and sometimes even a portion of the fourth. This allows the body to retain some of its natural parathyroid function. Removing the parathyroid glands and any associated tumours should cure most cases of primary hyperparathyroidism.
If surgery is not possible for any reason, patients may be treated with a drug called cinacalcet. This drug works by reducing PTH secretion and therefore decreasing calcium levels in the blood. Some common side effects include:
- Appetite loss
- Back or muscle pain
- Nausea or vomiting
- Electrolyte imbalances
- Shortness of breath
- Low blood pressure
For SHPT, treatment involves correcting the underlying cause of the condition. This includes treating any kidney issues, possibly with dialysis and supplementing vitamin D if necessary.
Drugs called bisphosphonates can be used as a short-term treatment to help prevent bone loss associated with hyperparathyroidism. These drugs should be taken before food, along with a full glass of water. The patient will need to stand or sit upright for 30 minutes after their dose. This will ensure that the medication reaches the stomach and prevent side effects such as difficulty swallowing and irritation in the esophagus.
In addition to these hyperparathyroidism treatments, patients can manage their condition by making a few simple lifestyle changes.
Although they do not need to avoid calcium completely, people with hyperparathyroidism should avoid consuming too much in their daily diets. This means also being cautious of vitamin and mineral supplements which may contain calcium.
Some foods which are especially high in calcium include:
- Dairy products
- Leafy greens
- Soy products like tofu and soy milk
- Fortified bread and cereals
- Fish with edible bones such as sardines
It is also important for hyperparathyroidism patients to drink plenty of fluids to avoid dehydration. They should avoid certain types of diuretic (water tablet) which can cause dehydration and increase calcium levels in the blood.
Taking these measures should help to keep the symptoms of hyperparathyroidism under control and reduce the risk of developing serious complications.