Phosphorus blood test

Phosphorus - serum; HPO4^-2; PO4^-3; Inorganic phosphate; Serum phosphorus

A blood sample is needed.

Your health care provider may tell you to temporarily stop taking medicines that may affect the test. These medicines include water pills (diuretics), antacids, and laxatives.

DO NOT stop taking any medicine before talking to your provider.

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.

Phosphorus is a mineral the body needs to build strong bones and teeth. It is also important for nerve signaling and muscle contraction.

This test is ordered to see how much phosphorus is in your blood. Kidney, liver, and certain bone diseases can cause abnormal phosphorus levels.

Normal values range from 2.4 to 4.1 mg/dL.

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

A higher than normal level (hyperphosphatemia) may be due to many different health conditions. Common causes include:

• Diabetic ketoacidosis (life-threatening condition that may occur in people with diabetes)
• Hypoparathyroidism (parathyroid glands do not make enough of their hormone)
• Kidney failure
• Liver disease
• Too much vitamin D
• Too much phosphate in your diet
• Use of certain medicines such as laxatives that have phosphate in them

A lower than normal level (hypophosphatemia) may be due to:

• Alcoholism
• Hypercalcemia (too much calcium in the body)
• Hyperparathyroidism (parathyroid glands make too much of their hormone)
• Too little dietary intake of phosphate
• Very poor nutrition
• Too little vitamin D, resulting in bone problems such as rickets (childhood) or osteomalacia (adult)

Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)