Serum Alkaline Phosphatase

An Alkaline Phosphatase, serum test (ALP test) measures the amount of alkaline phosphatase enzyme in your blood. It is an enzyme found in all body tissues with maximum concentration in liver, bones and bile duct. Elevated levels of ALP indicate bone or liver disorder.
This test is done as a part of the liver function test or if one experiences symptoms of a liver disorder like loss of appetite, vomiting, abdominal pain, and jaundice. It is also often prescribed in case of a possible bone disorder such as bone pain, susceptibility to bone fractures, or abnormal bone shape.
Higher than normal levels of ALP may indicate a problem with your liver or gallbladder like hepatitis, cirrhosis, liver cancer, and gallstones.

The alkaline phosphatase, serum test measures the alkaline phosphatase levels in the blood. Alkaline phosphatase (ALP) is an enzyme which is found in various tissues throughout the body. The maximum concentrations of ALP are present in cells of bone and liver. Usually, raised levels of ALP are caused due to liver disease or bone disorders.

ALP is found in the liver on the cell edges that join to form bile ducts. The bile ducts are the tiny tubes which drain bile from the liver to the bowels. The bile juice formed is required by the small intestine to help digest fat in the diet.

ALP is produced by osteoblasts cells in the bone which are involved in bone formation. The various tissue types produce distinct forms of ALP which are known as isoenzymes.

The levels of ALP generally increase to a great extent if one or more bile ducts get blocked. The reason could be inflammation of the gallbladder which is known as cholecystitis or presence of gallstones. Small amount of increase of ALP in blood can be seen in liver cancer and cirrhosis. These high levels can also be observed if there is intake of medications toxic to the liver and hepatitis.

In conditions, where there is formation of excessive bones such as Paget’s disease one can also have increased levels of ALP. Along with that, higher blood ALP levels can be seen in children and adolescents, as they are in the growing stage and so are their bones.