Substance guides

Blood tests for alcoholism: What doctors look for

Published January 28, 2025 · 7 min read · Updated April 2026
Reviewed for accuracy by licensed clinical professionals.

Several blood tests can indicate heavy alcohol consumption, even when the person denies or minimizes drinking.

Tests

GGT: most sensitive marker, elevated in 75% of heavy drinkers. MCV (mean corpuscular volume): enlarged red blood cells from folate deficiency. CDT (carbohydrate-deficient transferrin): highly specific for heavy drinking over 2+ weeks. Liver enzymes (ALT, AST): elevated with liver damage. Complete metabolic panel: liver function and nutritional status.

Clinical use

These tests help diagnose AUD, monitor treatment progress, and provide objective evidence of abstinence or continued use.

Authoritative sources

This article references guidelines from: NIDA · SAMHSA · CDC

Frequently asked questions

How do I find help?
Call SAMHSA at 1-800-662-4357 or search our directory at treatmentassociation.com/directory.
Does insurance cover treatment?
Yes. Most insurance covers substance abuse treatment under the Mental Health Parity Act.
Is this treatable?
Yes. Addiction is a treatable medical condition. Recovery is possible at any stage.

Disclaimer: Informational only. Not medical advice. SAMHSA: 1-800-662-4357.