Alkaline Phosphatase Level Test

What does alkaline phosphatase level test mean?

An alkaline phosphatase level test is that which analyzes the concentration of alkaline phosphatase enzyme in a person’s blood. For this test to be performed, blood must be drawn from the subject. Other blood tests also require drawing blood from the subject.

If the levels of alkaline phosphatase are abnormal, then it may be an indication of disorders in some vital organs of the body such as the bones, the liver, and the gallbladder. It may also be an indication of kidney cancer tumors, issues with the intestine, malnutrition, an infection, or even pancreas disorder. There is a variation in the normal range of alkaline phosphatase. This variation depends on one’s age, gender, blood type, and pregnancy status.

Studies suggest that the normal level of serum alkaline phosphatase is about 2-140 IU/L. However, there may be variations among laboratories. The range is higher in children and decreases as one gets older. To know the normal level, one must discuss the test results with a physician. The physician will then be able to interpret the laboratory’s specific results and reference ranges.

What exactly is alkaline phosphatase?

Alkaline phosphatase is simply an enzyme. This enzyme is found in the bloodstream. It helps in protein metabolism. It is present in different forms, depending on its origin. One of the major sources of alkaline phosphatase is the liver. Some quantity is produced in the bones, kidneys, pancreas, and intestines. In women who are pregnant, alkaline phosphatase may also be made by the placenta.

Is it necessary to take an alkaline phosphatase level test?

Yes! It helps the clinician to determine the health of your liver or gallbladder or to check if your bone has some problems.

Gallbladder and liver

Analyzing the level of alkaline phosphatase in the blood helps check the functionality of the gallbladder and the liver. Jaundice, nausea, abdominal pain, and vomiting are symptoms that may prompt your physician to order an alkaline phosphatase level test.

Other conditions that may be identified with the alkaline phosphatase level test include:

An alkaline phosphatase level test is also necessary if one is taking medications that have the potential to hurt the liver. Such medication includes acetaminophen, also known as Tylenol. Alkaline phosphatase level test can be used alongside other liver function tests to check for damage to the liver.


Alkaline phosphatase level test can also be used to diagnose bone disorders such as:

  • Osteomalacia
  • Rickets
  • Paget’s disease.

The test also proves helpful in checking for the presence of cancerous tumors, deficiency of vitamin D, and unusual bone growth. It may also be used to monitor the progress of treatment for the conditions that have been mentioned above.

Preparing for the alkaline phosphatase level test

It is a routine to have one’s blood drawn for an alkaline phosphatase level test. The test is usually done in combination with other kidney and liver function tests. The subject may have to undergo a 10-12 hour fast prior to the test. Aside from the fast, there is nothing else to do in preparation for the test. If the results are inconclusive, then the physician may order a follow-up test.

The alkaline phosphatase level can be altered by eating. Medications also cause a change in the level of one’s alkaline phosphatase. When going on a consultation visit, be sure to inform your physician of the medications you are taking.

How is an alkaline phosphatase level test done?

For the test to be done, a small quantity of blood will be drawn from your arm. This can be done in a clinical laboratory or a physician’s office. The skin on your elbow front will be cleaned with an antiseptic, and an elastic band applied to allow blood to pool in the vein. A needle will then be inserted into the vein to draw the blood into a tube. This is a quick process and very little discomfort or pain is experienced.

Any risks associated with an alkaline phosphatase level test?

Drawing blood carries very few risks. A little bruise may be experienced at the site of the puncture. This can, however, be avoided by applying some pressure on the wound. In some cases, the vein may be inflamed. If this complication shows up, then you may apply a warm compression until the swelling decreases. If you have been using blood thinners, or have any bleeding disorders, then be sure to inform your physician before the blood is drawn.

Results of an alkaline phosphatase level test

Upon getting your test results, your doctor will discuss with you what they mean, and advise you on the next line of action.

High levels

If the level of alkaline phosphatase in your blood is higher than normal, then it may be a sign of a problem with your gallbladder or liver. This may include cirrhosis, hepatitis, and cancer of the liver, and obstruction of the bile ducts or even gallstones.

High levels of ALP may also be an indication of bone disorders such as rickets, bone cancer, Paget’s disease, or a hyperactive thyroid gland. Sometimes, it may indicate cancer of the kidney, heart failure, or infection by a bacteria.

Low levels

Low blood ALP levels are quite rare. However, when it does occur, it may be a sign of malnutrition, which may be caused by a deficiency of some minerals or vitamins, and celiac disease.