What is kidney disease?Kidney disease is when the kidneys don't work well. Normally, the kidneys filter blood and remove waste and excess salt and water .

What bone problems can be caused by kidney disease?Kidney disease can cause different types of bone problems. These problems usually start early in kidney disease. If they are not treated, they will get worse as the kidney disease gets worse.

Doctors might use the terms "renal osteodystrophy" or "chronic kidney disease-mineral and bone disorder" for the bone problems caused by kidney disease.

How does kidney disease cause bone problems?When the kidneys don't work normally, the levels of certain substances in the body can get too high or too low.

Kidney disease commonly causes:

●High levels of phosphate (also called phosphorus) – Phosphate is a mineral found in many foods. Foods with high levels of phosphate include milk and other dairy foods, nuts, meat, eggs, beans, liver, and chocolate.

●Low levels of vitamin D

●Low levels of calcium

●High levels of parathyroid hormone (also called "PTH") – PTH is a hormone made by a gland in the neck called the parathyroid.

Phosphate, vitamin D, calcium, and PTH all affect each other. Bone problems happen when the levels of these substances get out of balance.

What are the symptoms of bone problems caused by kidney disease?Early in kidney disease, people usually have no symptoms from their bone disease. But they do have a higher chance of breaking a bone. Later, people who get a treatment for kidney disease called "dialysis" might have symptoms from their bone disease, such as:

●Bone, joint, or muscle pain

●Weakness

Will I need tests?Yes. Your doctor will order blood tests to measure the levels of phosphate, calcium, vitamin D, and PTH in your blood. People usually need to have these blood tests repeated on a regular basis.

Other tests that people might have include:

●X-ray

●Bone density test – Bone density testing measures how strong your bones are. It involves a special kind of X-ray.

●Bone biopsy – For this test, a doctor takes a small sample of your bone (usually from your hip). Then, another doctor looks at it under a microscope.

How are bone problems caused by kidney disease treated?Your treatment will depend on:

●How severe your kidney disease is

●Your age

●Whether you get dialysis treatment for your kidney disease

●Your levels of phosphate, calcium, vitamin D, and PTH

In general, treatment for bone disease involves different parts.

The first part of treatment often involves lowering your phosphate level. This can include:

●Diet changes – You might need to avoid eating foods that are high in phosphorus. But your doctor might recommend that you keep eating meat and eggs. Even though these foods are high in phosphorus, they are a good source of protein. To help you plan your meals, you will probably work with a dietitian (food expert).

●Medicines – Medicines called "phosphate binders" can help lower phosphate levels in the blood. There are different types of phosphate binders. Some contain calcium. Examples of these include calcium carbonate and calcium acetate. Others do not contain calcium. Examples of these include sevelamer (brand names: Renagel, Renvela) and lanthanum. Phosphate binders should be taken with food.

Other treatments for bone problems caused by kidney disease can include:

●Vitamin D medicines – These treat or prevent low levels of vitamin D.

●A "calcimimetic" medicine – This is a type of medicine that works like calcium in the body.

These treatments will usually help lower the level of PTH in your body. But if they don't, your doctor will talk with you about other treatment. This might involve surgery to remove your parathyroid glands.