what happens if parathyroid hormone is high

3 min read 08-03-2025

what happens if parathyroid hormone is high

Parathyroid hormone (PTH) is a vital hormone regulating calcium levels in the blood. When PTH levels are consistently elevated—a condition known as hyperparathyroidism—it can lead to a cascade of health problems. This article explores the consequences of high parathyroid hormone, its causes, and the importance of diagnosis and treatment.

Understanding Parathyroid Hormone and its Role

Before delving into the effects of high PTH, let's briefly review its normal function. The parathyroid glands, four tiny glands located behind the thyroid gland in your neck, produce PTH. This hormone plays a crucial role in maintaining calcium homeostasis. When blood calcium levels drop, PTH is released to increase them. It does this by:

Stimulating the release of calcium from bones: This process can weaken bones over time.
Increasing calcium absorption in the intestines: The intestines absorb more calcium from food.
Increasing calcium reabsorption in the kidneys: The kidneys retain more calcium that would otherwise be excreted in urine.

What Happens When Parathyroid Hormone is High? The Consequences of Hyperparathyroidism

Sustained high levels of PTH disrupt this delicate balance, leading to a range of symptoms and health complications. These can vary significantly depending on the severity and duration of hyperparathyroidism.

Common Symptoms of High Parathyroid Hormone

Many individuals with mild hyperparathyroidism experience no noticeable symptoms. However, as PTH levels rise, various symptoms may appear, including:

Bone pain and weakness: High PTH causes excessive calcium to be drawn from bones, leading to weakened bones and increased risk of fractures (osteoporosis). This can manifest as bone pain, particularly in the back, hips, and ribs.
Kidney stones: Increased calcium in the blood leads to a higher likelihood of calcium deposits forming in the kidneys, resulting in kidney stones. These can cause excruciating pain and potentially lead to kidney damage.
Fatigue and weakness: The disruption of calcium balance can lead to generalized fatigue and muscle weakness.
Mental changes: Some individuals experience cognitive impairment, including memory problems and confusion.
Gastrointestinal issues: Nausea, vomiting, constipation, and abdominal pain can occur.
High blood pressure: Elevated calcium levels can contribute to hypertension (high blood pressure).

Serious Complications of Untreated Hyperparathyroidism

If left untreated, hyperparathyroidism can cause serious long-term health problems:

Severe osteoporosis: This can lead to an increased risk of fractures, even from minor falls. These fractures can be debilitating and require extensive medical care.
Kidney failure: Persistent high calcium levels can damage the kidneys over time, potentially leading to chronic kidney disease and eventually kidney failure, requiring dialysis or kidney transplant.
Cardiovascular problems: Hyperparathyroidism is associated with an increased risk of heart problems, such as heart rhythm abnormalities and cardiovascular disease.

Causes of High Parathyroid Hormone

Hyperparathyroidism can be caused by several factors:

Primary hyperparathyroidism: This is the most common type and results from a problem within the parathyroid glands themselves. This often involves one or more overactive parathyroid glands producing excessive PTH. Often, this is due to a benign tumor (adenoma) on a parathyroid gland.
Secondary hyperparathyroidism: This develops in response to low blood calcium levels. Chronic kidney disease is a common cause of secondary hyperparathyroidism because the kidneys play a crucial role in regulating calcium and phosphorus balance. Vitamin D deficiency can also contribute.
Tertiary hyperparathyroidism: This occurs after prolonged secondary hyperparathyroidism. The parathyroid glands become autonomous, continuing to produce excess PTH even after the underlying cause (like kidney disease) is addressed.

Diagnosis and Treatment of High Parathyroid Hormone

Diagnosis of hyperparathyroidism typically involves blood tests to measure PTH levels and calcium levels. Further tests, such as imaging studies (ultrasound, CT scan), may be needed to pinpoint the cause of the high PTH.

Treatment for hyperparathyroidism depends on the underlying cause and severity of symptoms. Options include:

Medication: In some cases, medications can help manage symptoms and lower calcium levels.
Surgery: For primary hyperparathyroidism, surgery to remove the overactive parathyroid gland(s) or tumor is often the most effective treatment.

When to Seek Medical Attention

If you experience any of the symptoms mentioned above, it's crucial to consult a doctor. Early diagnosis and treatment of hyperparathyroidism are essential to prevent serious long-term complications. Don't hesitate to seek medical attention if you have concerns about your parathyroid hormone levels. Early intervention is key to preserving bone health, kidney function, and overall well-being.