Hyperparathyroidism – Symptoms and Causes

Primary Hyperparathyroidism

Primary hyperparathyroidism happens when there’s a problem with one or more of the four parathyroid glands themselves. These small glands are located in the neck near the thyroid, and they directly control calcium levels in your blood.

In this condition, the glands produce too much parathyroid hormone without a good reason. This extra hormone raises calcium levels in your blood above normal while lowering phosphorus levels.

The most common cause (about 80% of cases) is a benign tumor called an adenoma. This small, non-cancerous growth makes the gland overproduce hormone regardless of the body’s needs.

Other causes include:

• Gland Enlargement (Hyperplasia) – when two or more glands grow larger than normal.
• Parathyroid Cancer – extremely rare, accounting for less than 1% of cases.

Most cases of primary hyperparathyroidism occur randomly. However, some people inherit genetic changes that make them more likely to develop this condition.

Common symptoms may include:

• Bone pain or fractures
• Kidney stones
• Excessive urination
• Abdominal pain
• Fatigue or weakness
• Memory problems

Many patients, however, have no obvious symptoms. They find out they have the condition through routine blood tests that show high calcium levels.

Secondary Hyperparathyroidism

Secondary hyperparathyroidism develops when another condition causes low blood calcium levels. The parathyroid glands work correctly but must produce extra hormone to maintain normal calcium balance.

Think of it this way: the glands aren’t malfunctioning. They’re working overtime to fix a problem happening elsewhere in the body.

The most common causes include:

1. Chronic Kidney Disease: The leading cause of secondary hyperparathyroidism. Kidneys normally activate vitamin D, which helps absorb calcium. When kidneys fail, vitamin D levels drop, calcium levels fall, and parathyroid hormone rises.

2. Severe Vitamin D Deficiency: Without enough vitamin D from sunlight or diet, your body can’t properly absorb calcium from food.

3. Digestive Disorders: Conditions that prevent proper absorption of calcium or vitamin D, including:
   • Celiac disease
   • Crohn’s disease
   • Previous intestinal surgeries, including weight loss surgery

In severe cases of long-standing secondary hyperparathyroidism, the parathyroid glands may become permanently overactive. This condition is called tertiary hyperparathyroidism and often requires surgical removal of some parathyroid tissue.

Treatment approaches differ significantly between primary and secondary forms. Primary hyperparathyroidism usually needs treatment of the gland, whereas secondary hyperparathyroidism targets the underlying cause of low calcium levels.

Blood tests measuring calcium, phosphorus, and parathyroid hormone levels help doctors determine which type of hyperparathyroidism is present and guide appropriate treatment.