Q: What does a high Alkaline Phosphatase mean?

The first thing to do is checking your laboratory’s reference ranges. As mentioned previously, ranges may vary by a considerable margin across different age groups. A high ALP is foreseeable during the second and third trimesters of pregnancy due to ALP production in the placenta; similarly, bone growth during childhood or adolescence may result in higher ALP levels than those seen in adults.[3][4] ALP levels may also increase when you are recovering from a bone fracture.[3] If you have a high ALP, it means that your tissues are producing and releasing more ALP than usual; typically, this is caused by problems of the liver or the bones. To confirm this, your GP would have to examine you and maybe request other tests to identify the source. ALP test is usually included with other liver function tests, which helps to determine if the problem comes from the liver or the bones. If ALP is high when compared with other liver function tests, it probably comes from the bones. If ALP and other liver function tests are increased to the same extent, it likely comes from the liver.[1] In some cases, a high ALP is observed in conditions that require surgical intervention, such as bile duct obstruction. It can also be seen in people with acute and chronic liver disease, bone diseases, and many types of bone and liver cancer.[1] According to recent studies, having high ALP levels could: Increase the risk of developing diabetes in people with hypertension.[6] Increase the risk of cardiovascular disease in people with chronic kidney disease.[7] Predict the risk of liver fibrosis in patients with obesity and non-alcoholic fatty liver disease.[8]

Question 1

What is an Alkaline Phosphatase blood test?

Accepted Answer

Alkaline Phosphatase (ALP) is an enzyme that can be measured in the blood through an ALP blood test, which is very useful during the differential diagnosis of conditions that affect the liver or bones. As an enzyme, ALP is in charge of speeding up certain chemical reactions in different parts of the body. It is commonly found in the liver, bones, intestines, kidneys, and placenta;[1][2] however, the majority of the ALP measured in the blood comes from the liver and bones.[1][3]

It is recognised that ALP plays a role in bone mineralization, and it may also participate in the intestinal transport of phosphate[2] and contribute during bile production.[4] Nonetheless, most of the functions that ALP carries out in other tissues remain unknown.[2]

ALP has multiple forms (also known as &lsquo;isozymes&rsquo;) specific for each tissue. These include the placental ALP, intestinal ALP, germ cell ALP, and the tissue-nonspecific ALP; however, a general ALP test measures the tissue-nonspecific ALP, which is the most commonly needed.[2] Considering that isozyme testing is more expensive and unnecessary for most conditions, your GP may indicate an ALP isozyme test in very specific situations.[3]

The ALP test can be performed on its own, but you may need other tests to clarify any abnormalities. Typically, the ALP test is taken alongside other liver function tests.

Question 2

When should I take an Alkaline Phosphatase blood test?

Accepted Answer

You will usually need testing for ALP as part of a medical check or if your GP suspects that you have a liver or bone problem, both of which are the most frequent causes of high ALP.[4]

Signs and symptoms that may suggest liver problems include jaundice (yellowish skin), nausea, vomiting, dark urine, pale stools, or pain near the liver. On the other side, clinical findings that may be suspicious of bone problems include dull bone pain, fractures, kidney problems, and hyperthyroidism. If you present some of these symptoms, the sooner you consult your GP, the better your outcome might be.

A commonly overlooked reason to check your ALP levels is the use of antihypertensive medication (like enalapril, captopril, ramipril, and others) or hormones (like oestrogen).[4]

Question 3

What is considered a high Alkaline Phosphatase?

Accepted Answer

The ALP test usually measures your blood levels of ALP in units (U) per litre (L), but the reference ranges are different for each age group and, in some laboratories, for sex.[5] Different laboratories and regions may have slightly different ranges, too.


	3 &ndash; 10 years: 130 &ndash; 260 U/L.
	10 &ndash; 14 years: 130 &ndash; 340 U/L.
	14 &ndash; 18 years: 30 &ndash; 180 U/L.
	18 years or older: 30 &ndash; 130 U/L.


ALP is high when your values are over the upper limit, depending on your age. It is important to look for the reference ranges of your laboratory, especially when testing children and adolescents. The upper reference range may vary significantly during ages of high bone growth. Pregnant women may also have high ALP results.[3]

Note that when you take a Vitall liver function test your ALP results will always include current ranges for your age and sex.

Question 4

What does a high Alkaline Phosphatase mean?

Accepted Answer

The first thing to do is checking your laboratory&rsquo;s reference ranges. As mentioned previously, ranges may vary by a considerable margin across different age groups. A high ALP is foreseeable during the second and third trimesters of pregnancy due to ALP production in the placenta; similarly, bone growth during childhood or adolescence may result in higher ALP levels than those seen in adults.[3][4] ALP levels may also increase when you are recovering from a bone fracture.[3]

If you have a high ALP, it means that your tissues are producing and releasing more ALP than usual; typically, this is caused by problems of the liver or the bones. To confirm this, your GP would have to examine you and maybe request other tests to identify the source. ALP test is usually included with other liver function tests, which helps to determine if the problem comes from the liver or the bones. If ALP is high when compared with other liver function tests, it probably comes from the bones. If ALP and other liver function tests are increased to the same extent, it likely comes from the liver.[1]

In some cases, a high ALP is observed in conditions that require surgical intervention, such as bile duct obstruction. It can also be seen in people with acute and chronic liver disease, bone diseases, and many types of bone and liver cancer.[1]

According to recent studies, having high ALP levels could:


	Increase the risk of developing diabetes in people with hypertension.[6]
	Increase the risk of cardiovascular disease in people with chronic kidney disease.[7]
	Predict the risk of liver fibrosis in patients with obesity and non-alcoholic fatty liver disease.[8]

Question 5

Should I be worried if my Alkaline Phosphatase is high?

Accepted Answer

If your general condition is good, but you have a mildly elevated ALP, it may not be something to worry about too much; your GP may ask you to repeat the test and monitor your liver function for a few days to see if everything is normal.[1]

A moderate elevation (up to 4 times the upper limit) is observed during chronic conditions that affect the liver, such as cirrhosis and chronic hepatitis. However, Hodgkin lymphoma (a type of cancer) and acute abdominal infections may elevate ALP levels too. Bone-related problems that lead to high ALP levels include Paget disease, hyperparathyroidism, osteomalacia, osteosarcoma, and bone metastasis.[1]

However, a very high ALP could mean that you have a condition that requires medical attention, sometimes urgently. Very high levels of ALP (4 times the upper limit) usually reflect intense damage; these include acute and chronic conditions that may have severe consequences if left unresolved.[1] Bile duct obstruction (which can be caused by gallstones and some types of cancer) may drastically increase ALP levels and even require surgical intervention.[9]

Question 6

What causes a high Alkaline Phosphatase?

Accepted Answer

High ALP levels are caused by a wide variety of conditions, but the most common are related to liver and bone problems. A mild ALP elevation might occur without any significant reason; depending on the patient&rsquo;s condition, it may only warrant periodic monitoring of liver function.[1] If it persists, a throughout evaluation may be required, even when you are not showing any symptoms.[4]

Very high levels of ALP may reflect acute or significant damage, and it can be seen in the following conditions:[1]


	Choledocholithiasis.
	Drug-induced liver injury.
	Severe alcoholic hepatitis.
	Pancreatic head cancer.
	Liver and bile duct cancers.


Moderate to high ALP elevation is observed in people with conditions characterised by chronic liver damage, such as cirrhosis, chronic hepatitis, and heart failure. Similarly, acute infections (intra-abdominal infections or osteomyelitis) may also cause high ALP levels. Bone problems that produce high ALP levels include Paget disease, hyperparathyroidism, vitamin D deficiency,[1][2] osteomalacia, osteosarcoma, and bone metastasis.[1]

If you have high ALP, the reason might be a liver problem if you present some of the following symptoms:


	Jaundice (yellowish skin).
	Pain in the liver area.
	Dark urine.
	Pale stools.


On the other hand, these clinical findings are common in people with bone diseases:


	Bone pain, usually dull.
	Fragile bones or frequent fractures.
	Poor growth.
	Bone deformities.
	Cavities (dental caries).

Question 7

How can I decrease my Alkaline Phosphatase levels?

Accepted Answer

The best way to decrease your ALP levels begins with treating its cause. Your GP may need to request other tests before reaching the correct diagnosis. However, if your ALP levels are only slightly over the upper limit, you may not need special treatment. Depending on your case, your GP will guide you.

If you have high ALP or would like to prevent it, you can:


	Follow your treatment if you have an underlying condition.
	Avoid drinking alcohol or smoking.
	Have a balanced diet.
	Incorporate exercise into your routine.
	Take vitamin D or get more sun exposure.


You may ask your GP for advice before making any significant change in your lifestyle. Taking any drug without supervision, including not taking your medications as indicated, may lead to further liver damage and higher ALP levels.

Question 8

How long does it take for Alkaline Phosphatase levels to return to normal?

Accepted Answer

Depending on the severity of the cause, ALP levels will decrease over time after successful treatment. It will usually take at least a week because that is the time it takes for the body to clear up ALP from the blood.[4] Such is the case of patients with an acute bile duct obstruction due to gallstones (choledocholithiasis) or acute infections.

People with chronic conditions may need more time before a significant recovery. In these cases, ALP decreases more slowly and may persist slightly above the upper limit.

Question 9

What is the process for an Alkaline Phosphatase blood test?

Accepted Answer

The ALP test requires a sample taken by a fingerprick or directly from a vein with a needle. Most usually, you will be taking this test as part of a liver function test. Vitall offers the Liver Function Home Test Kit, a fingerprick test that includes ALP, gamma-glutamyl transferase (GGT), alanine aminotransferase (ALT), albumin (ALB), bilirubin, globulins, and total protein (TP).

The fingerprick Vitall tests are very simple to use and contain the instructions inside each box. It is a convenient way of testing yourself from home and getting reliable results online in 24 hours.

Wash your hands before taking your sample. Take one lancet and press it firmly against the skin of your little finger, although any finger will work. Wipe away the first drop of blood and fill your collection tube until it reaches the upper mark. Then, close the tube and gently turn it over between five to ten times. Do not forget to label your sample before sending it.

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The Alkaline Phosphatase test is also known as a Alk. Phos. test.

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