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Alkaline Phosphatase

Medically reviewed by Drugs.com. Last updated on Feb 21, 2024.

What is it?

Alkaline phosphatase (FOS-fah-tays) is also called Alk Phos. It is an enzyme (EN-zeyem) found in your bones and liver. An enzyme is something that helps speed up a chemical reaction in your body. This blood test measures the amount of alkaline phosphatase in the blood.

Why do I need it?

This is a test to help caregivers see how well your bones are healing or growing, and how your liver is working. The amount of alkaline phosphatase in your blood may go up if you have a bone problem such as a fracture, bone cancer or Paget's disease. Young children have higher levels of alkaline phosphatase because their bones are growing. Hepatitis or liver cancer are other conditions that make your alkaline phosphatase level increase. This test may be used to see how medicines are working if you have liver or bone disease.

How do I get ready for the test?

Your caregiver will tell you when to have your blood test done. Do not eat or drink anything, except water, for at least 12 hours before the test. You may need to stop taking some medicines before the test. Ask your caregiver if you should take your usual medicines before your blood is taken.

How is the specimen collected?

A caregiver will put a wide rubber strap around your arm and tighten it. Your skin will be cleaned with alcohol. A small needle attached to a special test tube will be put into a vein (blood vessel) in your arm or hand. The tube has suction to pull the blood into it. When the tube is full, the rubber strap, needle and tube are removed. The caregiver will press a piece of cotton where the needle was removed. You may be asked to hold the cotton on the site for a few minutes to help stop the bleeding. Tape may then be put over the cotton on your arm.

What should I do after the test?

You may remove the tape and cotton in about 20 to 30 minutes. Take your usual medicines as instructed by your caregiver. Call your caregiver to get the results of your test. Your caregiver will explain what your test results mean for you. Follow the instructions of your caregiver.

Care Agreement

You have the right to help plan your care. To help with this plan, you must learn about your lab tests. You can then discuss the results with your caregivers. Work with them to decide what care may be used to treat you. You always have the right to refuse treatment.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.