Alkaline Phosphatase » Diseases, Functions and Values

Alkaline Phosphatase » Diseases, Functions and Values
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The alkaline phosphatase is an enzyme hydrolase that runs through the blood system, its function is defophorylation, this discards various types of phosphates such as proteins and alkaloids, alkaline phosphatase is found in all tissues of the body but more than anything in liver, kidneys, placenta, intestinal system and others.

A test to understand alkaline phosphatase scenarios is commonly done by medication, performing a blood test. For the purpose of tracking various pathologies related to bone marrow, liver, intestine, bones. This substance plays a metabolic role of fats in the blood system, which is why when showing signs such as stomach upset, it is necessary to perform a hemogram to understand and interpret the values of the enzyme.

Although in lower proportions, alkaline phosphatase is also found in the placenta, kidney and intestine, so it may be elevated in pregnancy or in cases of kidney failure.

Main characteristics

Characteristics of Alkaline Phosphatase
FunctionElimination of phosphates rooted in various molecules, such as nucleotides, proteins and alkaloids.
Latin nameAlkaline phosphate
Cell typeHydrolase enzyme


Alkaline phosphatase test

What is the alkaline phosphatase test?

The alkaline phosphatase test measures alkaline phosphatase (ALP) scenarios in the blood. This enzyme is found throughout the body, but primarily in the bones, liver, kidneys, and intestinal system. When an organ such as the liver is damaged, ALP can leak into the bloodstream. Higher alkaline phosphatase scenarios have the potential to signal possible liver problems or bone-related pathologies.

Why do I need an alkaline phosphatase test?

The alkaline phosphatase test should be performed at the onset of symptoms or signs of a liver disorder, such as jaundice, pain on the right side of the abdomen, generalized itching. On the other hand the APL test is suggested to people who have a bone disease, usually at the level of the bones, such as deformities or people who have suffered a fracture.

It is the duty of your health care professional to request an alkaline phosphatase test, making it part of a routine check-up or if you have harmful symptoms in the liver region or a pathology in the bone area. Some symptoms or pathologies in the liver are the following:

  • Weight Loss
  • jaundice
  • Abdominal swelling
  • General strong itching
  • Nausea, vomiting
  • Fatigue
  • Weakness
  • Inflammation

Symptoms in the bony area may be manifested with pain in the bones or joints, deformed or elongated bones, as well as frequent fractures.


Is any kind of prior preparation necessary?

The alkaline phosphatase test does not require any previous or particular preparation. Depending on the requirements of the physician or professional, additional tests may be required. The doctor may ask you not to eat any food for hours before the test. It is important that you tell your doctor about your diet and the type of medication you are taking before the test. So all this happens around any test, there are some drugs that help raise the enzymes of alkaline phosphate.

Medications such as cortisone, chlorpromazine, propanol and other analgesics raise alkaline phosphatase.

Tranquilizers, antidepressants, hormones, and some arthritis drugs have an elevating effect on the APL enzyme. The dangers of an alkaline phosphatase test are minimal, you may feel a slight swelling or pain in the area where the needle is inserted, these disappear quickly.


How to interpret the results

Higher alkaline phosphatase scenarios would have the potential to be a sign of liver inconvenience or some kind of bone pathology. The liver inconvenience creates a different type of ALP than a bone disease. If the results indicate higher alkaline phosphatase scenarios, your physician or health care professional may request additional tests to learn the origin of the increased alkaline phosphatase. Symptoms of having elevated alkaline phosphatase in the liver may be:

  • Hepatitis
  • Inflammation in the liver
  • Cirrhosis
  • Blockage in the bile ducts

There are several blood tests to find out about the performance of the liver. Tests on alanine transaminase or bilirubin. In the event that the results of these are normal, and those of the alkaline phosphatase test are superior, the disadvantage would be a case like Paget’s pathology, causing bone deformation, weakness, and exposure to fractures.

Balanced upper alkaline phosphatase scenarios have the potential to signal drawbacks such as lymphomas, bacterial disease, or heart failure.

Low alkaline phosphatase scenarios have the potential to be a sign of hypophosphatase, an unusual genetic pathology that harms bones and teeth. Low scenarios also have the potential to be due to zinc deficiency or malnutrition. To grasp the concept of your results, consult your doctor or health care professional.



Reference values for the enzyme alkaline phosphatase vary with human growth and age.

The normal values of blood AF in our environment, with the sample at 37 C. are shown in Table.


Normal alkaline phosphatase values in the laboratory
1 days<600
2 – 5 days<553
6 days – 6 months<1076
7 months – 1 year<1107
2 – 3 years<673
4 – 6 years<644
7 – 12 years<720
13 – 17 years
> 18 years


Recommended values
Recommended blood test resultsFrom 120- 220 U/L (International units per liter)


Symptoms showing unevenness of alkaline phosphatase

The alkaline phosphatase test is commonly ordered by doctors to administer liver and bone health, but these have to be linked to prior indications that there is some inconvenience with these organs. If you have these signs, it is advisable to go to a doctor because you probably have alkaline phosphatase values that are too high or too low.

  • Vomiting
  • Weight loss
  • Jaundice problems, or changes in skin color
  • Nausea
  • Swelling in the abdomen
  • Weakness and extreme tiredness
  • Joint pain


High alkaline phosphatase

Sometimes, the values increase due to causes that are not related to particular pathologies, they have the possibility of indicating intestinal inconveniences. One of the main causes that we have the possibility of feeling are abdominal pains, vomiting, dizziness, and different inconveniences that directly damage the liver.


 What causes elevated alkaline phosphatase?

The enzyme alkaline phosphatase can be found in much of the tissues of the body, is a substantial section of the blood system, so it is required to take into account when the values are elevated. This increase directly suggests hepatic inconveniences, such as hepatitis or cirrhosis. This is why a doctor must be informed of this elevation. Some symptoms that arise when there is an ALP elevation.

  • Leukemia

    The leukemia virus seen from a microscope
  • Hypothyroidism
  • Liver diseases: hepatitis, fatty liver, cirrhosis, cholangitis
  • Rickets (due to lack of vitamin C)
  • Arthritis
  • Tumors: testicular, ovaries, lung
  • Bone metastasis


Why do alkaline phosphatases increase?

Alkaline phosphatase may be elevated if there are actions in the liver. An obstruction of the bile flow, caused by cancer or gallstones. There is also an increase in enzymes if you suffer from hepatitis, which inflames the liver caused by bacteria or toxic products. Diseases such as Cirrhosis, kidney failure and consumption of fatty foods contribute to a high level of alkaline phosphatase.


The enzyme may be very high at times when there is an increase in bone formation activities, such as deformities or some types of bone cancer, in people with Paget’s pathology. This pathology develops an abnormal state in some parts of the bone.

There is also the possibility of mild changes occurring throughout pregnancy healing cycles, fractures, HIV, Hodgkin’s lymphoma, intestinal infections or even after an excessive meal in fat.

Low alkaline phosphatase

Among the main symptoms of low levels of alkaline phosphatase in the body, are fatigue and weakness, breathing problems, causes of having low levels of the enzyme can be:

Leukemia: Leukemia is a type of cancer of the blood that begins in the bone marrow, the soft tissue located in the center of bones, where blood cells form.

The term leukemia means white blood. White blood cells, or leukocytes, are produced in the bone marrow and are used by the body to eliminate infections and other foreign symptoms.

Zinc deficiency: Zinc deficiency is caused in people with a genetic disorder, not in all cases. A malabsorption of zinc from the food you eat or in circumstances where there are large losses of Zinc, such as diarrhea or burns. This deficiency of Zinc causes lesions in the sight, diarrhea, loss of the hair and diminishes the appetite. Weight loss is consequent, problems with wound healing, among others. 

Magnesium deficiency

Poor nutrition

Congenital diseases

Deformation in the osseous system

Hypothyroidism: Occurs when the thyroid gland does not produce the necessary thyroid hormone to stabilize the body. Hypothyroidism is recurrent in women, in people with various thyroid problems, and in people over 60 years of age.

Severe diarrhea

Hypophaspathy: A genetic disease that deforms and fractures the osseous system.


In addition to this, some medications, including birth control pills and hormone replacement therapy medications used at menopause, may also cause a slight decrease in alkaline phosphatase levels.


Alkaline phosphatase increases or decreases according to the person’s growth and health status. Here are some answers.

What is alkaline phosphatase in the blood?

Alkaline phosphatase in the blood is an enzyme present throughout the bloodstream. Problems arise when this enzyme is elevated or decreases in amounts above recommended normal values. With a blood test we have the possibility to measure the scenarios of the enzyme that inhabits every tissue of our body. Alkaline phosphatase represents the health of the kidneys, intestine and bones. With a blood test we have the possibility of locating hepatic pathologies.


What is alkaline phosphatase normal values?

The normal values of alkaline phosphatase represent the balance and the appropriate percentage that this enzyme should have in the bloodstream of the human body. Values vary depending on the person’s growth status and age. Normal ranges may vary depending on the laboratory where the test is done.

The recommended values for the enzyme in adults aged 22 and older are 120-230 U/L .


High alkaline phosphatase causes cancer?

High alkaline phosphatase levels may be signs of damage to the intestines, liver, pharynx, or some type of bone disease. Being consequent to disease or imbalance may be caused by cancer of the organs or bones. Any disease increases its resistance over time and deteriorates the body, thus becoming a cancer difficult to treat. It is advisable to perform the APL test to detect the causes of an elevation of phosphatase enzymes or deficiencies of it. A medical professional may order additional tests in order to know what causes the increase in alkaline phosphatase.

Alkaline phosphatase in children

High levels of alkaline phosphatase are usually seen in children who have a sudden increase in growth and in pregnant women.                                                                                     

APL values in children vary:

  • under to 2 years: 500 – 600 U / L
  • 2 to 9 years: 590 – 700 U / L

It is preferable to know if the child suffers any symptom or disease related to alterations or deficiencies of alkaline phosphatase.

You can consult the reference ranges and measurements for blood tests:  Reference ranges for blood.


Alkaline phosphatase in pregnancy

During pregnancy, the blood values of alkaline phosphatase have the possibility of being subtly altered, due to the development of the newborn child and because this enzyme is also found in the placenta.

In addition to this test, the evaluation of other enzymes that are in the liver such as total and fractionated bilirubin, AST, ALT, in addition to imaging tests or in fact a liver biopsy may be requested.


Alkaline Phosphatase considerations of normal range, nursing and laboratory values

Alkaline phosphatase (ALP) is an enzyme that can be found in several places in the body. Liver, bile ducts, bone, intestine, and placenta each contain a different ALP isoenzyme. These isoenzymes are used to diagnose and monitor bone disease, liver disease, gallbladder and bile duct diseases as well as determining bone turnover in postmenopausal women.


Health professionals, medical test: Reference ranges for blood test.

Martin P. Approach to the patient with liver disease: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia

Clinical and biological significance of an isozyme tumor marker–PLAP. Clin Biochem

Table of Normal Values:  Normal values are based on medical laboratory investigations attached to the