Cholinesterase: What the Test Results Mean

What Is Cholinesterase?

Cholinesterase is an enzyme found mainly in the blood and liver. It helps break down certain chemicals that affect nerve and muscle function.

This biomarker is often used to assess liver function and to detect exposure to specific toxins. Cholinesterase levels can change when the liver is not working properly or when the body is exposed to substances that interfere with nerve signaling. Because the enzyme is produced in the liver, its level reflects how well the liver is functioning.

When Is Cholinesterase Testing Recommended?

Cholinesterase testing is ordered when liver health or toxin exposure is a concern.

Common reasons include:

• Suspected liver disease or liver damage
• Monitoring chronic liver conditions
• Possible exposure to organophosphates or similar toxins
• Unexplained weakness or nerve-related symptoms
• Occupational exposure risk, such as agricultural or industrial work
• Follow-up after known toxin exposure

How Is Cholinesterase Testing Conducted?

Cholinesterase is measured through a blood test. A blood sample is taken from a vein in your arm and analyzed in a laboratory.

The test evaluates enzyme activity in the blood rather than nerve tissue. It is not part of routine panels like CBC or CMP and is usually ordered separately.

In most cases, no special preparation is required. Your doctor may ask about recent exposures, supplements, or lifestyle factors that could affect enzyme activity.

What Are the Normal Cholinesterase Levels?

Typically, normal pseudocholinesterase values range between 8 and 18 units per milliliter (U/mL) or 8 and 18 kilounits per liter (kU/L).

Note: The units of measurement and the normal ranges can differ depending on the laboratory and the specific methods used.

What Do Low Levels Mean?

Low cholinesterase levels are more clinically significant. They often suggest reduced liver function or toxin exposure.

Possible causes include:

• Liver disease: Reduced enzyme production reflects impaired liver function.
• Organophosphate exposure: These substances block cholinesterase activity.
• Malnutrition: Poor nutrition can reduce enzyme synthesis.
• Chronic infections: Long-term illness may affect enzyme levels.
• Genetic variants: Some people naturally have lower enzyme activity.

Recommendations

• Avoid further exposure to potential toxins.
• Follow up with liver function testing if recommended.
• Support liver health through nutrition and lifestyle changes.
• Seek medical evaluation if neurological symptoms appear.

Which Specialist Should You Consult?

A hepatologist is the primary specialist for abnormal cholinesterase levels related to liver health.

Depending on the cause, you may also be referred to:

• An occupational medicine specialist for toxin exposure
• A neurologist for nerve-related symptoms
• A toxicologist for confirmed chemical exposure