All of your body tissues contain a protein called alkaline phosphatase, or ALP for short. Your bones, liver and bile ducts contain especially high amounts. Your doctor primarily orders an ALP test to help detect liver disease. He may also order one if a bone disorder is suspected. Liver and bone diseases elevate your ALP blood levels. Your doctor can evaluate your ALP levels and discuss any concerns.
Blocked Bile Ducts
Checking for bile obstruction is a common reason for ordering an ALP test. Your liver makes a substance called bile and stores it in your gallbladder, a small organ. When you eat fat-containing food, your gallbladder contracts and releases bile to emulsify and digest the fat. Bile ducts carry bile from the liver to the gallbladder and intestines. Conditions such as gallstones and pancreatitis can cause bile blockage. When this happens, bile builds up in your liver and can cause abdominal pain, pale stools and vomiting.
Abnormally Low Levels
Normal ALP levels range from 44 to 147IU/L. Keep in mind that ranges vary depending on the lab. It is important to use the ranges from the lab that conducts your test. Your doctor is able to evaluate your test results. An abnormally low level can indicate zinc deficiency. Blood transfusions and heart bypass surgery can also cause ALP levels to drop.
Abnormally High Levels
An abnormally high ALP blood level can indicate liver or bone problems. If your levels are higher than normal, your doctor will order additional tests to help determine the cause. Liver cancer and hepatitis -- a liver disease -- can cause elevated ALP levels also. Ordering additional tests will help your doctor rule out other causes. Your doctor may order a bilirubin test to further evaluate liver function if he suspects a liver problem. Bilirubin is a substance your liver makes.
Symptoms to Watch
Your doctor will take a detailed account of your symptoms to help determine the problem. Conditions that affect your liver can cause appetite loss, nausea, fever, fatigue and yellowing of the skin, known as jaundice. You may also lose weight. Bone diseases such as Paget's disease can cause abnormal ALP levels also. Symptoms include joint pain, joint stiffness, hearing loss and headache. If you have abnormal ALP levels, discuss your concerns with your doctor.
