What Level Of Alkaline Phosphatase Is Dangerous? Complete Guide

What Level Of Alkaline Phosphatase Is Dangerous

Alkaline Phosphatase (ALP) is an enzyme found in various tissues of the body, including the liver, bones, kidneys, and intestines. It has numerous bodily processes, most notably the breakdown of proteins.

However, a high level of ALP in the blood can be indicative of serious health conditions, like liver disease or bone disorders. Understanding the implications and dangers of elevated ALP levels is important to maintaining optimal health.

This comprehensive guide explores the question, “What Level of Alkaline Phosphatase is Dangerous?” We also discuss the importance of ALP in the body, what can cause it to change, and how these changes can affect our health.

Alkaline phosphatase (ALP) is a hydrolase enzyme that is found throughout the body. It is responsible for dephosphorylating many substances, including proteins, nucleotides, and alkaloids.

The enzyme is present in some tissues mainly include in the liver but it also exits in other body parts like:

  • Your bones.
  • Your kidneys.
  • Your bile duct.
  • Your intestines.
  • The placenta in pregnant people.

Abnormal changes in ALP levels in your blood can indicate tissue damage or disruption of normal bodily processes.

In healthy adults, ALP levels usually range between 20 to 140 units per liter (U/L). High levels of ALP can cause medical conditions such as liver disease, bone disorders, or certain cancers.

In contrast, low levels might reveal malnutrition or a deficiency in certain vitamins. Therefore, it’s important to maintain a balanced ALP level which is crucial for overall health.

Note that ALP levels can vary depending on factors such as age, gender, blood type, and even pregnancy.

Causes of an elevated alkaline phosphatase

Elevated levels of alkaline phosphatase (ALP) in the blood usually show that there may be an issue with the liver or bones.

These heightened levels may be a result of liver diseases like hepatitis, cirrhosis, or liver cancer. Hepatitis in particular can cause liver inflammation and damage which results in increased ALP levels.

On the other hand, bone disorders like Paget’s disease, osteomalacia, or bone cancer can also cause a rise in ALP levels. Paget’s disease, for instance, is a condition that disrupts the normal cycle of bone renewal which causes bones to become larger, weaker, and more susceptible to fractures.

Additionally, there are some other medical conditions that can also cause elevated ALP levels. These can include:

  • Biliary atresia
  • Heart disease
  • Lymphoma
  • Cancer
  • Amyloidosis
  • Hyperthyroidism

Note that physiological causes, like pregnancy, can also cause an elevation in ALP levels, particularly in the third trimester due to increased activity in the placenta.

If you observe any abnormal or persistent changes, seek medical advice from a healthcare professional for better examination.

Symptoms of high alkaline phosphatase levels

People with high levels of alkaline phosphatase (ALP) might not always display symptoms which makes it crucial for regular check-ups and routine blood work. However, when symptoms do occur, they are usually related to the underlying cause of the elevated ALP.

In the case of liver diseases, symptoms can range from:

  • Jaundice (a yellowing of the skin and eyes)
  • Itchy skin — Due to the buildup of bilirubin (a yellow pigment in your blood) as a result of liver dysfunction.
  • Swelling or Abdominal pain — This can be caused by fluid retention in the abdominal area.
  • Unexplained weight loss
  • Having dark-colored pee and/or light-colored poop.
  • Nausea
  • Fatigue

For bone disorders, symptoms might include:

  • Bone pain
  • Deformities in bone structure
  • Fractures
  • Muscle weakness

Further, in cases of some types of cancer or cardiac conditions, additional symptoms might manifest such as:

  • Unusual fatigue
  • Persistent fever
  • Unintentional weight loss
  • Chest pain or discomfort

Note: Early detection and diagnosis can lead to more effective treatment and better management of the condition.

What are normal alkaline phosphatase levels?

Normal levels of alkaline phosphatase (ALP) can vary depending on factors like age, gender, blood type, and whether you’re pregnant.

The ALP range can differ from person to person and depends on factors like age, blood type, gender, and pregnancy status.

A 2013 research review showed that the normal range for a serum ALP level in healthy adults is 20 to 140 units per liter (U/L). It is important to note that these values can vary slightly depending on the lab that analyzes the blood sample.

Children and adolescents often have higher ALP levels due to bone growth, and pregnant people may also see an increase in ALP, especially in the third trimester.

Keeping within this range is important for maintaining balanced body functions. If your ALP levels are not within the normal range, it could mean there is an underlying health issue. It’s best to get further medical evaluation to be sure.

Related: What Level of Alkaline Phosphatase is Dangerously Low?

What level of alkaline phosphatase is dangerous?

what level of alp is dangerous

When alkaline phosphatase levels in the body significantly exceed the normal range, it can be dangerous.

High ALP levels can become dangerous if left unchecked and may cause serious problems with the liver, bones, or overall health.

According to NIH, a normal level of ALP in human blood typically falls between 25 and 100 IU/L. However, when the ALP concentration exceeds 300 IU/L, it may indicate various diseases such as liver diseases, liver cancer, bone disease, hepatitis, kidney cancer, and osteoblastic bone cancer.

According to Science Direct, pregnant women with the lowest ALP levels (≤116 U/L) in late pregnancy had a higher risk of VTE postpartum compared to those with the highest levels (≥199 U/L) (OR, 2.83 [1.32, 6.05]).

Importantly, a single high reading doesn’t always mean there’s a long-term health problem. Fluctuations can happen because of temporary factors like certain medicines or short-term illnesses. It’s when ALP levels stay consistently high that it might suggest a more serious underlying issue.

Must Read This: 7 Foods to Avoid If Alkaline Phosphatase Is High

What is an alkaline phosphatase (ALP) blood test?

The Alkaline Phosphatase (ALP) blood test is used to determine the level of ALP enzyme in your bloodstream. The test is quick, simple, and relatively painless.

ALP is found in different parts of your body, but the liver and bones are the main sources of ALP in your blood. If your ALP levels are high, it could be a sign of liver disease or certain bone disorders. However, an ALP test alone cannot diagnose a specific condition.

A general ALP test is usually a part of a blood test known as a CMP and a liver panel (HFP or LFT).

During this test, a doctor will draw a small quantity of blood, usually from a vein in your arm. This sample is then sent to a lab for analysis. An ALP blood test can give important information about a person’s health. It helps detect and treat diseases early.

Keep in mind that the ALP test is often part of a routine liver panel, and it may be accompanied by other tests to give a complete picture of a person’s liver function.

Why do I need an alkaline phosphatase blood test?

An alkaline phosphatase (ALP) blood test may be required for many reasons. Doctors usually order this test as part of routine check-ups or when there are symptoms suggesting liver and biliary diseases or bone disorders.

It is also used to monitor the effectiveness of prescribed treatments for these conditions. For example, if you have been diagnosed with a liver disease like hepatitis, an ALP test can help your doctor understand how well your treatment plan is working.

In some cases, the test might be ordered if you have symptoms like severe itching, persistent fatigue, abdominal pain, or if you notice a yellowing of the skin and whites of the eyes (jaundice).

These symptoms may indicate a possible liver dysfunction. Similarly, if you experience bone pain, have sustained fractures easily, or notice changes in the shape of your bones, an ALP test could help investigate the potential cause.

Remember, while an ALP test is a reliable indicator of bone and liver health, it is not definitive. Abnormal ALP levels could be a result of other factors like medication or a temporary illness. It’s always recommended to talk with your provider for a complete understanding of your results.

Do I need to fast for an alkaline phosphatase blood test?

No, fasting is not usually required for an alkaline phosphatase test. You can eat and drink normally before the test.

But if your doctor asks for a comprehensive metabolic panel (CMP), which includes ALP, it might be better to fast so that they can get accurate measurements of your glucose and lipid levels.

There are some medications that can affect the results of the ALP test, so it’s crucial to inform your healthcare provider about any prescription or over-the-counter drugs, vitamins, or supplements you’re taking.

When getting an ALP blood test, what can you expect?

During an alkaline phosphatase blood test, you can expect a quick and simple procedure that is not very painful. Here’s what you can expect:

Preparation for an ALP Blood Test

Before getting an ALP blood test, your doctor will give you clear instructions on how to prepare for it. It might include fasting (not eating or drinking) for 10 to 12 hours before the test.

Certain medications and supplements may also affect test results, so be sure to discuss any medications you’re taking with your doctor.

The Procedure

During the ALP blood test, your provider first clean the area where the needle will be inserted. A tourniquet (a stretchy band) will be placed around your upper arm to make the veins easier to see.

The needle used to draw blood will be inserted into a vein in your arm. A small amount of blood is then drawn into a vial or syringe. After the blood is collected, the needle is removed, and a small bandage is applied to the puncture site.

The Results

ALP blood test results are usually available within a few days. Normal ALP levels range from 20 to 140 IU/L, but these values can vary depending on the laboratory.

High ALP levels might indicate liver disease or damage, bone conditions, or certain infections. Lower than normal ALP levels could suggest malnutrition or certain genetic disorders.

Keep in mind that ALP levels alone cannot definitively diagnose a condition. Your doctor will consider your overall health and other test results to interpret the results accurately.

CMP vs. ALP: What is the Difference?

A CMP, or Comprehensive Metabolic Panel, and ALP, Alkaline Phosphatase, are both blood tests, but they measure different things and are used for different purposes.

A CMP is basically a collection of 14 tests that give information about the health of your kidneys, liver, electrolyte levels, acid/base balance, blood sugar, and blood proteins.

In contrast, an ALP test measures the amount of the enzyme alkaline phosphatase in your blood. Abnormal levels of ALP can indicate liver disease or damage, blockage of the bile ducts, certain types of cancer, or bone disease, among other conditions.

The CMP gives a big picture of your overall health that includes markers of liver function, while the ALP test focuses on specific organs like the liver or bones when there are concerns.

Remember that while these tests can indicate possible issues, further tests are usually needed to make a definitive diagnosis.

What does it mean when your alkaline phosphatase is high?

High levels of Alkaline Phosphatase (ALP) in your blood can indicate a problem with your liver or bones. Certain conditions like liver cirrhosis or hepatitis, gallstones, or a blockage in your bile ducts can cause elevated ALP.

Plus, bone diseases like rickets, Paget’s disease, or osteomalacia might be a possible cause. Furthermore, increased levels can also be seen in certain blood cancers, heart failure, mononucleosis, and during the healing process of a bone fracture.

Liver damage causes a different kind of ALP compared to bone disorders. If your test shows high ALP levels, your doctor may ask you to take additional tests, like an ALP isoenzyme test, to find out where the extra ALP is coming from.

High alkaline phosphatase levels in the liver may indicate the following conditions:

  • Liver disease (hepatitis, cirrhosis)
  • Cholestasis of pregnancy: A liver condition that can occur later in pregnancy.
  • Bile duct obstruction or injury
  • Mononucleosis (mono): A contagious infection that can occasionally lead to liver swelling.
  • Biliary atresia: A rare condition that occurs in infants when there is a blockage in the tubes that carry bile from the liver to the gallbladder.
  • Infection in the liver (hepatitis A, hepatitis B, hepatitis C)

If your ALP levels are high due to bone disorders, it might mean:

  • Paget’s disease: A condition that causes your bones to grow abnormally large, soft, and brittle.
  • Rickets: Weak and soft bones in children caused by a deficiency of vitamin D, calcium, or phosphate.
  • Bone cancer that affects osteoblasts (cells responsible for bone formation).
  • Osteomalacia: A condition in which bones become weak due to a lack of vitamin D and calcium absorption.
  • Hyperparathyroidism: It occurs when the parathyroid glands produce an excess of parathyroid hormone, leading to elevated levels of calcium in the blood.

What are the dangers of high alkaline phosphatase levels?

High alkaline phosphatase (ALP) levels can indicate problems with the liver or bones. If not properly treated, these issues can cause serious complications.

Liver-Related Complications

High ALP levels due to liver diseases may result in complications like:

  • Liver Failure: Chronic liver diseases like hepatitis or cirrhosis can cause liver failure, a life-threatening condition where the liver stops functioning properly. This can result in complications like jaundice, bleeding disorders, increased risk of infection, kidney failure, and even brain dysfunction.
  • Portal Hypertension: This condition involves high blood pressure in the portal vein system, which carries blood from the digestive organs to the liver. This can lead to complications like esophageal varices and ascites.

Bone-Related Complications

High ALP levels associated with bone disorders can result in complications such as:

  • Bone Pain and Fractures: Conditions like Paget’s disease or osteomalacia weaken the bone structure, resulting in pain and increased susceptibility to fractures.
  • Bone Deformities: In children, conditions like rickets can cause bone deformities like bowed legs or curved spine.

What are the risks of an alkaline phosphatase (ALP) test?

The risks related to the Alkaline Phosphatase (ALP) test are minimal and usually relate to the blood draw procedure. These might include slight pain or bruising at the injection site, lightheadedness, or, in rare cases, infection. However, these risks are generally outweighed by the diagnostic benefits the test provides in identifying liver or bone-related health issues.

Treatment of high alkaline phosphatase

The treatment for high alkaline phosphatase (ALP) levels mainly focuses on addressing the underlying cause.

For liver-related issues, approaches can include lifestyle modifications like a balanced diet, regular exercise, and avoidance of alcohol and non-prescription drugs. Medications may also be required to manage specific conditions like hepatitis or cirrhosis.

For bone-related diseases, therapies often include supplementation of deficient nutrients like calcium and Vitamin D, along with specific treatments for conditions like Paget’s disease or osteomalacia. This could include using bisphosphonates, which are a type of medicine that helps slow down the process of breaking down old bone.

In severe cases, surgical intervention may become necessary. For instance, bile duct obstructions might require surgery to clear the blockage, and certain bone disorders may necessitate orthopedic procedures.


In conclusion, the alkaline phosphatase (ALP) test is a critical diagnostic tool that helps detect conditions related to the liver and bones. High ALP levels can signal liver and bone diseases, each with its own potential complications if left untreated. The risks associated with the test are minimal and far outweighed by its diagnostic benefits. Treatment for high ALP levels primarily targets the underlying cause, whether it be a liver or bone disorder, with lifestyle modifications, medications, and in severe cases, surgical interventions being among the various approaches deployed.


How do doctors determine the cause of elevated ALP levels?

Doctors use diagnostic tests to find the cause of high alkaline phosphatase (ALP) levels. Initially, an ALP test is performed to measure the level of ALP in the blood. If the levels are high, an ALP isoenzyme test is usually ordered. This helps identify the source of the excess ALP, as different forms of this enzyme are associated with different tissues, like the liver or bones. To further pinpoint the cause, additional tests may be ordered based on the suspected underlying condition. For example, if there is a suspicion of liver disease, liver function tests or imaging studies such as ultrasound or CT scan may be done. If there is a suspicion of a bone disorder, bone scans or X-rays may be used.

Are elevated alkaline phosphatase levels always a cause for concern?

No, elevated alkaline phosphatase levels aren’t always a cause for concern. These levels can occasionally rise due to temporary conditions like stress or pregnancy. However, persistent high levels may indicate an underlying health issue that are related to the liver or bones and should be investigated with further diagnostic tests.

Can lifestyle factors affect alkaline phosphatase levels?

Yes, lifestyle factors can affect alkaline phosphatase levels. For example, consumption of alcohol or certain medications can affect the health of the liver, causing increased ALP levels. Similarly, lack of physical activity or poor diet, especially the deficiency of calcium and Vitamin D can contribute to bone disorders, thereby elevating ALP levels.

Can alkaline phosphatase levels fluctuate over time?

Yes, alkaline phosphatase (ALP) levels can fluctuate over time due to various factors. Temporary conditions like pregnancy, certain medications, or stress can cause short-term increases in ALP levels. In contrast, lifestyle changes, treatment of underlying conditions, or natural variations can result in decreases.

Can I lower my ALP levels with diet?

Yes, a balanced diet can help lower ALP levels, especially if they’re elevated due to liver conditions. Consuming foods low in fat and high in fiber, like fruits, vegetables, whole grains, and lean proteins can support liver health. Plus it’s very important to limit or completely avoid alcohol intake because it can seriously and permanently damage your liver.

Are there any symptoms of high ALP levels?

High ALP levels often do not show any noticeable symptoms. However, depending on the cause, symptoms may occur. For liver diseases, you might experience jaundice (yellowing of the skin and eyes), abdominal pain, dark urine, and fatigue. For bone illnesses, symptoms could include bone pain, deformities, and increased frequency of fractures.

How often should I check my ALP levels?

The frequency of checking your ALP levels depends on several factors like your current health status, age, and whether you have a history of liver or bone conditions. It’s often included in routine blood work, but if you’re at higher risk or experiencing symptoms of liver or bone disease, more frequent testing may be necessary.

What level of alkaline phosphatase is dangerous low?

A dangerously low level of alkaline phosphatase (ALP) can vary depending on the lab, but it’s generally considered low if it’s less than 30 U/L in adults. A low ALP level could indicate health problems like malnutrition, celiac disease, or a deficiency in vitamins like B6, B12, or C. But remember to talk to a healthcare professional for help understanding test results.

Is 400 alkaline phosphatase high?

Yes, an alkaline phosphatase level of 400 U/L is considered high. Normal ALP levels usually range from 20 to 140 U/L in adults, so a level of 400 U/L is significantly elevated. This could show a problem with your liver, bile ducts, or bones. However, it’s important to note that ALP levels can also increase due to factors like recent meals or medications.

Can ALP levels return to normal?

Yes, ALP levels can return to normal. The important thing is to treat the root cause of the high levels. When the condition is properly taken care of or resolved, ALP levels usually go down. However, some factors like age or pre-existing liver or bone disorders may affect how quickly the levels return to normal.

Can vitamin D deficiency cause high alkaline phosphatase?

Yes, vitamin D deficiency can potentially cause high alkaline phosphatase levels. A shortage of vitamin D can cause conditions like osteomalacia or rickets, which can stimulate the overproduction of ALP in the bones. Hence, adequate vitamin D intake is crucial for maintaining healthy ALP levels.

What foods to avoid if alkaline phosphatase is high?

If your alkaline phosphatase levels are high, it could be beneficial to avoid foods that are hard on your liver. These include processed foods, foods high in sugar, fried foods, excessive amounts of red meat, and alcoholic beverages. Instead, go for a well-rounded diet with plenty of fruits, vegetables, lean proteins, and whole grains.



The information provided in this article is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Don’t ignore professional medical advice or put off seeking it just because of something you read here. Although we aim to offer precise and current information, we do not guarantee its completeness, accuracy, reliability, suitability, or availability for any purpose. Using the information in this document is at your own risk. We are not responsible for any losses or damages caused by our content.

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