CDT, low-carbohydrate transferrin.

Test your long-term alcohol consumption

A CDT test is a blood test used to assess long-term alcohol consumption. If you are concerned about your alcohol habits, or simply want to gain a better understanding of how your alcohol intake may affect your body, a CDT test can provide valuable insight. The biomarker CDT (carbohydrate-deficient transferrin) increases in the blood with regular consumption of larger amounts of alcohol over an extended period.

By analyzing CDT levels in the blood, the test can provide an objective indication of alcohol consumption during the past few weeks. CDT is therefore often used in healthcare as a marker of risky alcohol use or when monitoring changes in drinking habits. The test can help you better understand how your lifestyle affects your health and support efforts toward a more balanced and healthier alcohol consumption pattern.

When you order a CDT test through us, you receive a clear and confidential test result that is shared only with you. The result is not registered in your regular medical record. This allows you to check your levels privately and calmly decide whether your alcohol habits may need adjustment.

What Is considered a high CDT level?

CDT normally represents a very small proportion of the total transferrin in the blood. In individuals with low or moderate alcohol consumption, CDT levels are typically below approximately 2.0 percent of the total transferrin in serum.

With regular consumption of larger amounts of alcohol over several weeks, CDT levels may rise above this threshold. An elevated CDT value may therefore indicate risky or harmful alcohol use. However, it is important to interpret the result in context, as individual variation can occur.

By analyzing the biomarker S-CDT, the test provides a reliable indicator of prolonged alcohol consumption. Many people use the CDT test as a tool to monitor changes in their alcohol habits over time, for example after reducing alcohol intake or during periods of abstinence.

Can an elevated CDT test affect your driver’s license?

A CDT test is primarily used as a medical tool to assess long-term alcohol consumption. In some cases, the test may be included as part of medical evaluations in healthcare, for example when investigating alcohol-related health problems or suspected alcohol dependence.

According to regulations from the Swedish Transport Agency (Transportstyrelsen), driver’s license decisions are not based on a single laboratory value alone. Since January 2026, an isolated test result is not used as an independent basis in driver’s license matters. Instead, decisions related to driving eligibility are made through a comprehensive medical assessment in which physicians consider multiple factors, such as overall health status, medical history, and possible follow-up testing.