What is an Alkaline Phosphatase (ALP) Blood Test? (2023)

An alkaline phosphatase (ALP) blood test evaluates a group of enzymes found in many parts of the body. Elevations in ALP may indicate a problem with the liver,Gall bladder, bile ducts, bones or other organ systems.

What is an Alkaline Phosphatase (ALP) Blood Test? (1)

Purpose of the trial

The ALP test technically measures the activity of a group of related enzymes (alkaline phosphatases). ALP can be used as a kind of medical marker of certain potential medical problems.

What is Alkaline Phosphatase?

These enzymes speed up certain chemical reactions in the body. The most common version of the ALP test evaluates multiple versions of these enzymes with a single value.

Scientists do not fully understand the physiological role of these enzymes, although they do know that ALP plays a role in bone mineralization.In medicine, alkaline phosphatases are important because their presence in the blood can provide information about damage to specific parts of the body.

Alkaline phosphatase is active in many different tissue types. The most important of these are the bones, liver, gallbladder and bile ducts. However, ALP can also come from other sources, such as the intestines, kidneys, or placenta during pregnancy.

So it's no surprise that measuring ALP can sometimes give clues to problems in these body systems. Abnormalities in ALP can be used along with symptoms, additional tests, and other clinical factors to help diagnose many different medical conditions.

(Video) Alkaline Phosphatase (ALP) | Lab Test 🧪

Medical significance

A number of different medical conditions in the liver and throughout the bile duct system can lead to elevated ALP. High ALP levels may indicate a problem with bile duct obstruction. These ducts normally transport bile produced by the liver and stored in the gallbladder to the intestines.

ALP is also elevated in certain diseases that affect the bones or the amount of calcium in the blood. Examples include;Paget's disease, hyperparathyreoïdie ofvitamin D deficiency.

Less commonly, other groups of medical conditions can reduce ALP, including malnutrition, hypothyroidism, and pernicious anemia.

Often, but not always, ALP is tested at the same time as several blood tests commonly used to diagnose liver disease, such asaspartate aminotransferase (AST) en (alanine aminotransferase (ALT). These tests may be done if you have liver disease or if you have symptoms suggestive of liver or gallbladder disease.

This may be necessary, for example, if you have jaundice, abdominal pain and nausea. Your doctor may also ask you to take ALP if you have symptoms that could be due to a bone disorder, such as bone pain.

Risks and contraindications

ALP is a simple blood test. Therefore, there are few contraindications. You may experience pain and bruising at the site of the blood draw. Contamination is also a minimal risk.

If you have a bleeding disorder or are taking a medicine that inhibits blood clotting, such as Coumadin, you may have an increased risk of bleeding. Before the test, make sure your doctor knows about all your medical conditions and medications.

For the trial

An overnight fast is usually recommended before taking an ALP test because fatty meals can affect the results by temporarily raising ALP levels.You may want to wear a loose shirt so that the phlebotomist can easily assess a vein in your upper arm.

(Video) Alkaline Phosphatase (ALP) Test - Diagnosing Bone and Liver Disorders

The test can be performed in a hospital or an outpatient clinic. Usually the process only takes a few minutes.

During the test

To perform the test, a healthcare provider must take a blood sample. First they clean the area. A tourniquet is then applied over the vein to be used, usually in the upper arm.

You may be asked to clench your fist while your phlebotomy finds a good vein to use. The needle is inserted into a vein in your arm. This usually only hurts for a moment or two.

The sample is drawn into a labeled tube to be sent to the laboratory. The needle is removed and the blood collection site is covered with a bandage or tape.

After the trial

The sample is immediately sent to a medical laboratory for analysis. You can usually resume your normal activities right away.

If you feel dizzy after the blood draw, you may need to sit down or have something to eat or drink before continuing with the rest of your day. You may have pain or bruising where your blood was drawn.

Interpretation of results

The test results should come back fairly quickly, within a day or so. Different laboratories may have different reference ranges. Roughly speaking, however, levels between 44 and 147 international units per liter (IU/L) are considered normal.

However, interpretation is sometimes a challenge. Normal ALP levels vary with factors such as age, gender, and even blood type. Adolescents may have elevated levels compared to adults due to active bone growth. ALP may also be slightly elevated in smokers compared to non-smokers.

(Video) Alkaline phosphatase (ALP) test and its significance

Pregnancy can temporarily raise ALP levels, even if there is no medical problem. ALP can also be temporarily increased by bone fractures or by certain medications.

These factors should be considered when making a diagnosis. Your healthcare provider can help you interpret your lab results and tell you if there is anything to worry about.

High ALP levels

Clinicians consider the degree of elevation when evaluating ALP levels in a medical context. For example, ALP is often four times higher than normal, or even higher in medical conditions that block the flow of bile out of the body. For example, this could be due to cancer blocking the ducts, gallstones in the bile ducts, or other causes.

Very high levels can also be found if significant liver damage causes bile to flow poorly from the ducts. This can happen due to an autoimmune diseaseprimary biliary cholangitisliver damage from drug use or severe hepatitis from alcohol use. Diseases that invade the liver can also cause this problem, such as cancer,sarcoidosisof amyloidosis.

If the height isn't that high, then other possibilities are more likely. This can be done, for example, by:

  • Cirrhosis of the liver
  • Viral hepatitis
  • Congestive heart failure
  • Abdominal infections
  • Hodgkin lymphoma
  • Hyperparathyreoïdie
  • Hyperthyroidism
  • Osteomyelitis
  • Bone cancer, or cancer that has spread to the bones
  • Osteomalacia

Low ALP levels

While high ALP levels are more common than low levels, low levels can be medically significant in some cases. For example, low ALP levels are sometimes found in the following medical conditions:

  • Hypothyroidism
  • Wilson's disease
  • Zinc deficiency
  • Pernicious anemia
  • celiac disease
  • Congenital hypophosphatasia

ALP can be used in the diagnosis of these and related conditions. It is also sometimes used to monitor these conditions after treatment.

I follow

You may not need a comprehensive medical evaluation if your ALP is only slightly elevated. Instead, your doctor may choose to monitor you with repeat blood tests. A slightly elevated ALP can occur in some people, even though there is no real problem. However, high levels require further medical investigation.

(Video) Causes Of High Alkaline Phosphatase In Blood | Symptoms Of High ALP |

Follow-up testing depends on the medical context: your symptoms and physical exam, other past and present medical conditions, other test results, etc. You may have taken the ALP test as part of itother tests to help evaluate the liver, which can provide more information about what your test results mean. If not, other blood tests that are often given to evaluate the liver may be needed.

Sometimes it is helpful to have a specific blood test called γ-glutamylpeptidase (GGTP) if someone's ALP is elevated. This test can help determine if the liver is the source of the growth or if it comes from somewhere else.

Sometimes it is also helpful to perform another type of ALP test (electrophoresis). This test provides information on the fraction of ALP coming from different organs, indicating the likely organ of concern.Usually these tests find the increase due to bone disease or problems with the liver or gallbladder.

Other blood tests may also be needed, depending on the context. For example, if your doctor is concerned that hepatitis may be the cause of your symptoms and ALP results, you may need to be tested for the hepatitis B and hepatitis C virus. Additional blood tests, such as anti-mitochondrial antibody (AMA), may also be needed. . AMA is a blood test that helps diagnose primary biliary cholangitis, a disease that damages the bile ducts in the liver and mainly affects women.

Abdominal ultrasoundit may also be useful as the first imaging modality to evaluate the liver, gallbladder and related structures.If necessary, other techniques can be performed, such as endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP).

Other tests, such as a liver biopsy, may be necessary in certain circumstances. Your doctor will work with you to identify the underlying cause.

A word from Verywell

ALP can be a useful diagnostic test, especially when performed in conjunction with other related tests. But your ALP may be slightly elevated, even if there's no real cause for concern. Talk to your doctor about all your questions. Together you can draw up the best possible diagnostic and treatment plan.


What is an Alkaline Phosphatase (ALP) Blood Test? ›

An alkaline phosphatase (ALP) test measures the amount of ALP in your blood. ALP is an enzyme found in many parts of your body. Each part of your body produces a different type of ALP. Most ALP is found in your liver, bones, kidneys, and digestive system.

What happens if alkaline phosphatase ALP is high? ›

High alkaline phosphatase (ALP) levels may indicate that there's damage to your liver or that you have a type of bone disorder. Liver damage creates a different type of ALP than bone disorders do.

When should I worry about alkaline phosphatase? ›

Values above 130 U/L are usually considered to be high.

Its major function is to protect your intestinal tract against bacteria, aid in digestion, breakdown fats and some B vitamins, and promote bone formation [1]. High levels of ALP in the blood may indicate bone, liver, or bile duct disease.

What does it mean when ALP is high in blood? ›

If your liver isn't working right, the amount of ALP in your blood may be high. Doctors often use the test to look for blocked bile ducts. Other conditions that can cause problems with your liver include: Liver cancer.

What is the normal range for ALP alkaline phosphatase? ›

The normal range is 44 to 147 international units per liter (IU/L) or 0.73 to 2.45 microkatal per liter (µkat/L). Normal values may vary slightly from laboratory to laboratory. They also can vary with age and sex. High levels of ALP are normally seen in children undergoing growth spurts and in pregnant women.

What disease causes high ALP? ›

High ALP levels can be caused by bone diseases, such as Paget's disease, osteomalacia, rickets, bone tumors, or tumors that have spread from another part of the body to the bone, or by overactive parathyroid glands (hyperparathyroidism). Normal healing of a bone fracture can also raise ALP levels.

How can I lower my ALP levels quickly? ›

How to naturally reduce Alkaline Phosphatase?
  1. Support Your Liver. If your alkaline phosphatase levels are high, you could look into natural ways to support the health of your liver. ...
  2. Omega-3 Fatty Acids. ...
  3. Stop Smoking. ...
  4. Coffee. ...
  5. Resistance Exercise. ...
  6. Sun Exposure/Vitamin D.
Dec 2, 2022

Can stress cause high ALP? ›

The short answer is yes — stress and anxiety can possibly cause elevated levels of liver-produced enzymes.

Does high alkaline phosphatase mean fatty liver? ›

A high alk phos level does not reflect liver damage or inflammation. A high alk phos level occurs when there is a blockage of flow in the biliary tract or a buildup of pressure in the liver--often caused by a gallstone or scarring in the bile ducts.

Can vitamin D deficiency cause high alkaline phosphatase? ›

Elevated serum alkaline phosphatase (ALP) level is an essential marker for the diagnosis of vitamin D deficiency (1). Some cases of vitamin D deficiency are diagnosed accidentally on the basis of elevated ALP levels. Therefore, cases without high ALP may be excluded from a diagnosis of vitamin D deficiency.

What organ does ALP affect? ›

What do the results mean? High alkaline phosphatase (ALP) levels may be a sign of a liver problem or a bone disorder. Liver problems and bone disorders cause different types of ALP. But your test results can't tell which type of ALP is high.

Can dehydration cause elevated liver enzymes? ›

In conclusion, hepatic enzymes can be temporary elevated in patients with uncomplicated acute AGE with severe dehydration.

What cancers cause high liver enzymes? ›

High levels can indicate tissue damage, such as liver or kidney disease, injury to the heart or other muscles, pancreatitis, some infections and some cancers, including lymphoma and leukemia.

What is normal range alkaline phosphatase by age? ›

ALP levels start to decline after 12 years of age in girls and after 14 years of age in boys, with upper ranges approaching the upper ranges of adults (240 U/L for females, 270 U/L for males) in girls (293 U/L), but not in boys (430 U/L) until they reach the ages of 16 to 18 years.

Can B12 cause high alkaline phosphatase? ›

Vitamin B12 in the concentration range from 10(-12) to 10(-8) mol/L concentration-dependently increased alkaline phosphatase activity in both hBMSC and UMR106 cells.

What vitamins help low alkaline phosphatase? ›

Focus on correcting the nutritional deficiency that is lowering your alkaline phosphatase levels. Get enough protein, B vitamins, zinc, and magnesium.

Does drinking water detox your liver? ›

Water helps the liver filter and remove all the toxins that it has absorbed from what we ate, drank, inhaled, or put on our skin. Not drinking enough water can cause these toxins to build up in the liver which can as a result affect the rest of your body and put you at risk of illnesses.

How much water should I drink to flush my liver? ›

Flush out with plenty of water intake: Water is the best flushing agent. It flushes your liver and kidney when taken optimally. Make sure you have 8-10 glasses of water daily.

Does drinking a lot of water help lower liver enzymes? ›

Hydration makes it easier for your blood to pass through the liver and thus, be filtered. Basically, the less hydrated you are, the less efficient your liver is at filtering out toxins like alcohol or chemicals.

What is ALP in liver failure? ›

ALP is an enzyme found in the liver and bone and is important for breaking down proteins. Higher-than-normal levels of ALP may indicate liver damage or disease, such as a blocked bile duct, or certain bone diseases.

Is 33 alkaline phosphatase low? ›

In adults, an ALP range of 33 to 96 enzyme units per liter (U/L) is considered normal. For children, this range is under 350 U/L. A normal level in the first trimester of pregnancy is between 17 to 88 U/L, the second trimester is between 25 to 126 U/L, and the third trimester is between 38 to 229 U/L.

What are the signs of a bad liver? ›

If signs and symptoms of liver disease do occur, they may include:
  • Skin and eyes that appear yellowish (jaundice)
  • Abdominal pain and swelling.
  • Swelling in the legs and ankles.
  • Itchy skin.
  • Dark urine color.
  • Pale stool color.
  • Chronic fatigue.
  • Nausea or vomiting.

Is ALP a kidney or liver? ›

Alkaline phosphatase (ALP) is an enzyme measurable in most body fluids and usually originates from the liver or bone.

What cancers cause low ALP? ›

Patients with solid cancer and bone lesions have a higher mean level of ALP (187.1 U/L) compared with MM (123.8 U/L) while the lowest levels of ALP can be found in patients with bone metastatic kidney cancer (that shows a mean level of ALP of 83.9U/L).

Is low ALP bad? ›

Occasionally, low alkaline phosphatase levels can indicate rare genetic conditions like: Hypophosphatasia – a genetic disorder that impairs bone growth and mineralization. Wilson disease – a genetic disorder that causes the accumulation of copper in the liver and other organs.

Is low alkaline phosphatase OK? ›

Low ALP is rare. It wouldn't be unusual for a doctor to disregard a low ALP result. But if you have low ALP, you should be aware that in some people it is a sign of hypophosphatasia—HPP—a rare disease that affects bones and teeth.


1. Alkaline Phosphatase Nursing Considerations, Normal Range, Nursing Care, Lab Values Nursing
(NURSINGcom w/Jon Haws, RN)
2. All about Alkaline phosphatase test?
(Basics of Biology)
3. ALP Blood Test | Alkaline phosphatase Test-Diagnosing Bone and Liver disorders
(Exclusive Lab Test)
4. Alkaline Phosphatase Test | ALP Test | Normal Range | Low ALP Causes | High ALP Causes
5. Is it okay to have increased ALP with other normal reports? - Dr. Anantharaman Ramakrishnan
(Doctors' Circle World's Largest Health Platform)
6. Alkaline Phosphatase Test | ALP Test, ALP Normal Range, Causes of Low ALP/High ALP & Its Functions?


Top Articles
Latest Posts
Article information

Author: Ouida Strosin DO

Last Updated: 26/10/2023

Views: 6647

Rating: 4.6 / 5 (76 voted)

Reviews: 83% of readers found this page helpful

Author information

Name: Ouida Strosin DO

Birthday: 1995-04-27

Address: Suite 927 930 Kilback Radial, Candidaville, TN 87795

Phone: +8561498978366

Job: Legacy Manufacturing Specialist

Hobby: Singing, Mountain biking, Water sports, Water sports, Taxidermy, Polo, Pet

Introduction: My name is Ouida Strosin DO, I am a precious, combative, spotless, modern, spotless, beautiful, precious person who loves writing and wants to share my knowledge and understanding with you.