Hyperparathyroidism

Hyperparathyroidism is a medical condition characterized by an overproduction of parathyroid hormone (PTH) by the parathyroid glands, which are four small glands located in the neck, behind the thyroid gland.

Causes and Risk Factors

• Primary Hyperparathyroidism: usually caused by a benign tumor (adenoma) on one of the parathyroid glands, which leads to an overproduction of PTH. Less commonly, it can be caused by hyperplasia (an increase in the number of cells) of all four parathyroid glands or, rarely, by a malignant tumor (carcinoma).
• Secondary Hyperparathyroidism: typically occurs as a result of vitamin D deficiency or chronic kidney disease. In these conditions, the body's ability to maintain normal calcium levels is impaired, leading to an increase in PTH production.
• Tertiary Hyperparathyroidism: usually develops from long-standing secondary hyperparathyroidism, where the parathyroid glands become overactive and start producing excess PTH even after the underlying cause has been treated.

Symptoms

Symptoms of hyperparathyroidism can vary widely among individuals. Some people may not experience any symptoms at all, while others may have:

• Fatigue and weakness
• Bone pain or osteoporosis due to increased calcium resorption from bones
• Kidney stones (nephrolithiasis) caused by high levels of calcium in the urine
• Abdominal cramps, nausea, and vomiting
• Depression or cognitive impairment
• Cardiovascular issues due to increased blood pressure and cardiac arrhythmias

Diagnosis

Diagnosis of hyperparathyroidism typically involves:

• Blood tests: to measure calcium, phosphorus, and PTH levels. Elevated calcium and PTH levels are indicative of primary hyperparathyroidism.
• Urine tests: to assess the level of calcium in the urine.
• Imaging studies: such as neck ultrasound, sestamibi scan, or CT/MRI scans to locate parathyroid adenomas or hyperplasia.

Treatment

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

• Surgery (parathyroidectomy): removal of the affected parathyroid gland(s) is often recommended for primary hyperparathyroidism, especially if symptoms are present or if calcium levels are very high.
• Medical management: for patients who cannot undergo surgery or have mild asymptomatic disease. This may include medications to manage symptoms and reduce calcium levels, such as bisphosphonates for bone protection and calcimimetics to lower PTH production.
• Vitamin D and calcium supplements: in cases of secondary hyperparathyroidism due to vitamin D deficiency or chronic kidney disease, correcting the underlying nutritional deficiencies can help manage the condition.

Complications

If left untreated, hyperparathyroidism can lead to several complications, including:

• Osteoporosis and increased risk of fractures
• Kidney damage and kidney stones
• Cardiovascular disease due to high blood pressure and altered lipid profiles
• Pancreatitis (inflammation of the pancreas) in rare cases, due to very high calcium levels

Prognosis

The prognosis for hyperparathyroidism varies depending on the underlying cause, severity of symptoms, and effectiveness of treatment. With appropriate management, many patients can experience significant improvement in their quality of life and reduction in the risk of complications.