Osteitis fibrosa is a complication of hyperparathyroidism (too much parathyroid hormone) in which the bones turn soft and become deformed.

There are four parathyroid glands in the neck. They produce parathyroid hormone, which helps control calcium levels in the body. Parathyroid hormone increases the break down of bone (bone metabolism). Too much parathyroid hormone (hyperparathyroidism) can lead to increased bone metabolism, which can cause bones to turn soft.

Rarely, parathyroid cancer may cause osteitis fibrosa.

Before 1950, about half of people diagnosed with hyperparathyroidism had osteitis fibrosa. Now it is uncommon, because patients with hyperparathyroidism are diagnosed earlier, before bone softening has occurred.

People with severe hyperparathyroidism have a higher risk for developing osteitis fibrosa.

Osteitis fibrosa may cause bone pain or tenderness. There may be fractures (breaks) in the arms, legs, or spine, or other bone problems.

Hyperparathyroidism may cause kidney stones, kidney problems, nausea, constipation, fatigue, and weakness.

Blood tests show a high level of calcium, parathyroid hormone, and alkaline phosphatase (a bone chemical). Phosphorus may be low.

X-rays may show thin bones, fractures, bowing, and cysts. Teeth x-rays may also be abnormal.

A bone x-ray may be done. People with hyperparathyroidism are more likely to have osteopenia (thin bones) or osteoporosis (very thin bones) than to have full-blown osteitis fibrosa.

Most of the bone problems of osteitis fibrosa are usually reversible with surgery.

Most patients with hyperparathyroidism have no symptoms, and many can be followed with blood tests and bone measurements. Others may need surgery to remove the abnormal parathyroid gland(s).

If surgery is not possible, drugs can sometimes be used to lower calcium levels.

The complications of osteitis fibrosa include bone fractures, pain, and deformities. There may be other problems stemming from the hyperparathyroidism itself, such as kidney stones and kidney failure.

A physician should be called if you notice bone pain, tenderness, or if you have a fracture or any of the symptoms of hyperparathyroidism.

Today, routine blood tests (done during a medical check up or for another health problem), usually detect high calcium levels before severe damage is done.