What Are the Symptoms of High Alkaline Phosphatase?

Alkaline phosphatase (ALP) is an enzyme that helps your body function at its best. But very high ALP levels can signal possible health problems. So, what are the symptoms of high alkaline phosphatase?

First, the basics: ALP is an enzyme found primarily in your liver, bones, kidneys and digestive system, according to the U.S. National Library of Medicine (NLM). But disease can spike ALP.

So what is the cause of high alkaline phosphatase levels? Often, conditions like liver disease or bone disorders are responsible for very elevated ALP, per the NLM.

And because underlying diseases are typically what cause alkaline phosphatase levels to be high, symptoms of these conditions can signal elevated ALP levels. Here are high alkaline phosphatase symptoms to look out for (including signs of high alkaline phosphatase in children).

If alkaline phosphatase is high, it can be a sign of liver disease, according to the NLM.

Other symptoms of that can signal high ALP from liver disease include:

• Nausea
• Vomiting
• Weight loss
• Fatigue
• Weakness
• Jaundice
• Swelling and/or pain in your abdomen
• Dark-colored urine and/or light-colored stool
• Frequent itchiness

Similarly, bile duct obstruction (also known as biliary obstruction) can be the cause of high alkaline phosphatase.

Bile is a liquid released by your liver that helps you digest, according to Mount Sinai. But if your bile duct is blocked, the substance can build up in your liver and cause issues, including high ALP.

Here are the other symptoms of elevated alkaline phosphatase from biliary obstruction:

• Abdominal pain in the upper right side
• Dark urine
• Fever
• Itching
• Jaundice
• Nausea
• Vomiting
• Pale-colored stools

What are other symptoms of high alkaline phosphatase? Bone problems.

That's because bone disorders can cause elevated ALP levels. According to the NLM, the following symptoms can indicate you have high ALP from a bone condition:

• Pain in the bones and/or joints
• Enlarged and/or abnormally shaped bones
• More frequent bone fractures

More specifically, bone tumors, osteomalacia, rickets and Paget's disease are some of the underlying conditions that may be responsible for elevated ALP, according to the UCSF Benioff Children's Hospitals.

If you're curious about symptoms that alkaline phosphatase is high in your child, the signs are much the same as those outlined above.

That's because the reasons for high alkaline phosphatase in children and teenagers are similar to adults: Typically, underlying liver, bile duct or bone conditions are at play, according to the UCSF Benioff Children's Hospitals.

Liver problems that cause alkaline phosphatase elevation in a child may be the result of hepatitis, liver disease or biliary obstruction, per the UCSF Benioff Children's Hospitals. These conditions can cause symptoms like those listed previously, including:

• Nausea
• Vomiting
• Fatigue
  
• Weakness
• Jaundice
• Abdominal pain
• Dark-colored urine and/or light-colored stool
• Itchiness

And if you're wondering what bone conditions cause high alkaline phosphatase in children specifically, rickets may be to blame. This disease causes bones to soften and weaken, often due to chronic vitamin D deficiency, according to July 2020 research in ​Kidney International Reports​.

Per the research, rickets causes elevated alkaline phosphatase in children. According to the Mayo Clinic, other symptoms include:

• Bowed legs or knock knees
• Abnormally curved spine
• Thick wrists and ankles
• Delayed growth
• Delayed motor skills
• Muscle weakness
• Pain in the pelvis, spine and legs
• Breastbone projection