normal ast levels by age

2 min read 17-03-2025

Meta Description: Discover normal AST levels by age and learn about factors influencing these liver enzyme tests. Understand what high or low AST levels may indicate and when to consult a doctor. This comprehensive guide provides valuable insights into interpreting your AST results.

Understanding your liver health is crucial for overall well-being. One key indicator is aspartate aminotransferase (AST), an enzyme primarily found in the liver and heart. This article will explore normal AST levels across different age groups, discuss factors influencing AST levels, and explain what high or low levels might signify.

What is AST?

Aspartate aminotransferase (AST), also known as serum glutamic-oxaloacetic transaminase (SGOT), is an enzyme found in various body tissues, most abundantly in the liver and heart. When these organs are damaged, AST leaks into the bloodstream, resulting in elevated levels. AST blood tests are commonly used to assess liver function and diagnose liver diseases.

Normal AST Levels by Age Group

It's crucial to understand that "normal" AST levels can vary slightly depending on the laboratory and the methods used. However, generally accepted ranges are as follows:

Note: These ranges are approximate and may vary slightly between labs. Always consult your doctor to interpret your individual results.

Infants and Children:

Newborns (0-1 month): 15-65 U/L
Infants (1-12 months): 20-50 U/L
Children (1-17 years): 10-40 U/L

Adults:

Adults (18+ years): 8-48 U/L (Some labs may give a slightly wider range)

Factors Affecting AST Levels

Several factors can influence AST levels, even in healthy individuals. These include:

Sex: Some studies suggest slight variations between males and females.
Race: Minor variations may exist across different racial groups.
Medications: Certain medications, like some statins and antibiotics, can temporarily elevate AST levels.
Physical Activity: Strenuous exercise can cause a temporary increase.
Recent Surgery: Surgical procedures can lead to a short-term rise in AST.
Certain Medical Conditions: Besides liver disease, other conditions like heart attacks, muscle damage (rhabdomyolysis), and pancreatitis can affect AST levels. These will necessitate further investigation.

High AST Levels (Hypertransaminasemia): What Could It Mean?

Elevated AST levels, often accompanied by elevated ALT (alanine aminotransferase), can point towards various health issues, including:

Liver disease: Alcoholic liver disease, viral hepatitis, non-alcoholic fatty liver disease (NAFLD), autoimmune hepatitis, cirrhosis.
Heart Conditions: Heart attack, heart failure.
Muscular Damage: Rhabdomyolysis (breakdown of muscle tissue)
Pancreatitis
Certain Cancers

If your AST levels are significantly elevated, your doctor will likely conduct further tests to pinpoint the underlying cause.

Low AST Levels: What Does This Indicate?

Low AST levels are less common and may not always indicate a problem. However, exceptionally low levels can sometimes suggest:

Severe Liver Damage: In some cases of advanced liver disease, AST levels can be unusually low due to extensive liver cell damage and a reduction in AST production.
Malnutrition: Nutritional deficiencies can impact liver function.
Rare Genetic Disorders: Some genetic conditions affect liver enzyme production.

When to See a Doctor

If you have concerns about your AST levels or experience symptoms like jaundice, abdominal pain, fatigue, or dark urine, consult your physician immediately. Your doctor will assess your overall health, review your medical history, and order further tests to provide an accurate diagnosis.

Conclusion

Understanding your AST levels can be a valuable tool in monitoring your liver health. While normal ranges vary slightly, consistently high or low levels require medical attention. Remember, this information is for educational purposes only, and it's essential to consult with your doctor for personalized advice and diagnosis. Regular checkups and open communication with your healthcare provider are crucial for maintaining optimal health.