Alkaline Phosphatase Blood Test: What Does Elevated Alkaline Phosphatase Mean?

What is alkaline phosphatase (ALP)?

Alkaline phosphatase (ALP) is an important enzyme found throughout the body including the intestines, kidneys, liver, bones, and in the placenta of pregnant women. However, the bone and liver contain the highest concentrations of ALP in the body because they are the organs that greatly manufacture the enzyme. ALP is needed in liver physiology and bone development. (1)
The blood contains ALP, which amount is maintained at a particular range of values. Gradual increase or decrease in blood ALP can indicate problems in the liver or bones. However, there are people that have high blood ALP but don’t have any liver or bone problems. They are children, adolescents, and pregnant women. Blood ALP is high in children and adolescents because their bones are growing. High blood ALP is natural to pregnant women because ALP is needed by the developing fetus. (2)


What is ALP blood test? When it is ordered?

ALP blood test measures blood alkaline phosphatase to detect liver and bone problems. It is ordered by the doctor if the patient has symptoms of liver or bone diseases.

The signs and symptoms of liver disease include itching, dark urine, light colored feces, jaundice, abdominal swelling and pain, nausea, vomiting, appetite loss, fatigue, and weakness. (2)

For bone disorders, signs and symptoms can include bone and/or joint pain, bone deformity, and increased frequency of fractures. (2)

ALP blood test is also ordered to monitor improvement in patients receiving medications for a particular liver or bone disease.

What is the normal range of blood alkaline phosphatase (ALP)?

The normal range of blood ALP in adults is 44 to 147 international units per liter (IU/L) according toMedline Plus Medical Encyclopedia. (3) However, according to WebMD the 30-126 IU/L is the normal range for adults and 30-300 IU/L for children. (4) The range can vary with gender and age, and from laboratory to laboratory. As discussed above, children, adolescents, and pregnant women have higher blood ALP. (3)

What does elevated alkaline phosphatase mean?

When the test results show that the patient has an elevated alkaline phosphatase, it means that either the liver is damaged or something is causing increased bone cell activity. ALP test does not tell which of the two (liver or bone) is causing increased ALP. To find out, the doctor orders more laboratory tests for the liver (e.g. bilirubin, aspartate aminotransferase (AST), GGT and alanine aminotransferase (ALT), 5-nucleotidase) and the bones (e.g. calcium and phosphate levels). (2)

If blood levels of bilirubin, AST, ALT, 5-nucleotidase, and GGT are high, ALP is coming from the liver. ALP is coming from the bone if calcium and phosphate levels in the blood are elevated. (2)

Liver problems that cause very high levels of blood ALP may include hepatitis, blockage of bile ducts, cirrhosis, gallstones, liver cancer, or cancer that has spread to the liver from another part of the body. (4)

Bone disorders that cause high levels of blood ALP can include Paget’s disease,  rickets, osteomalacia, bone cancer, or cancer that has spread to the bone from another part of the body. Overeactive parathyroid gland (hyperthyroidism) and healing bone fracture can also elevate blood ALP. (4)

What causes low ALP levels?

Low ALP levels can be caused by certain disorders including hypophosphatasia, anemia, leukemia, enteritis, hypothyroididsm, osteoporosis, malnutrition, magnesium deficiency, achondroplasia, cretinism, and protein deficiency.

What drugs can affect blood ALP levels?

Certain drugs can affect blood ALP levels. The doctor usually instructs the patient to stop taking the medications hours/days before the test. Drugs that can increase or decrease ALP levels include antibiotics, allopurinol, anti-inflammatory drugs, contraceptives, arthritis drugs, diabetes medications, chlorpromazine, cortisone, male hormones, narcotic pain relievers, methyldopa, tranquilizers, propanolol, and tricyclic antidepressants. The patient should not stop taking these medications without first talking to his doctor. (3)[ad#afterpost]

References and Further Reading

  1. ALP: Test Sample. Lab Test Online
  2. ALP: The Test. Lab Test Online
  3. ALP: MedlinePlus Medical Encyclopedia
  4. Alkaline Phosphatase. WebMD

{ 9 comments… read them below or add one }

Susan Lyle April 16, 2011 at 11:34 am

I have been diagnosed with extremely high Alkaline phosphate levels,within a month I have gained 40+ pounds in my abdominal area only,severe stabbing pains in my right side..running very high temp. Any suggestions?? I have a new prescription that i have just started taking.

Lloyda Hosman May 4, 2011 at 2:55 am

I am in one year of remission from stage 3 colon cancer and have a mild, persistent discomfort on my right mid side. Recent pet scan did not light up, but did show small lung nodules in both lungs, which we are monitoring, and a new ovarian cyst. CA 125 is elevated and Alk Phos is quite high. Could be the Cymbalta I am taking? This “discomfort on my right side is concerning me as it is .the same discomfort as when igot my cancer dx. Doctor does not seem concerned but should I be?

admin May 4, 2011 at 7:51 am


Trust your doctor. He/She knows what is best for you.

Thanks for visiting this site.

alicia May 10, 2011 at 3:20 am

my baby girl ( shes 18mnts old) had blood test done last friday with very high ALP 4950 :-( can anyone tell me what is that mean ???? please , I am very worried, other test are fine.

admin May 10, 2011 at 7:13 am


Please ask your doctor about this. Thank you.

Jamie June 9, 2011 at 2:40 am

Hi Alicia,

Have you heard anything else on your daughters results? My daughter is going through the same thing and we see a GI specialists in two weeks. Just wondering what the outcome has been for your lil one! My daughter is 17 months old and her ALP was 4700.

hare krishna money June 30, 2011 at 8:27 am

29th June 2011
Hi! Sorry to hear this news on ALP. Elevated ALP has common factor nowadays. People have various levels in their blood test. Nothing to worry. There are natural medications available in California Unfortunately the link has now gone from our net and we could not connect. Continuous activities and exercise possibly one of the solutions to control this factor subject to discussing with doctors. I am facing the same problem for the last 27 years elevated ALP. All tests have done so far no luck to control this. God only knows what is this and how it has come. On research of my life since birth, we noticed an incident of lifting 79 kgs and I laid down immediately. Right side bone affected. Doctors needed me to go for surgery. Avoided it. Eventually ALP has increased since then. Now it is 780. In case u can catch hold of this company in California they have suitable natural medications to control ALP. I am still trying to contact them.

May God Bless You
hare krishna money

H June 17, 2011 at 10:53 am

My daughter is 13 months and all tests were fine except ALP, which was 7000. Have either Alicia or Jamie gotten any answers as to what is causing the the elevated ALP in their little ones? We are currently waiting on more test results. I suspect celiac disease, but her celiac bloodwork was negative.

Francis - Mr June 18, 2011 at 6:25 pm

Last week my Liver Function Tests showned I have Alikaline Phospahatase of 128 IU/L — of range 39 – 117 IU/L. which is just above . What action should I take to prevent for it level to excdeed further. I am 73 year of age.