Dr Saal Seneviratne Expert Witness in Psychiatry

CDT Test

Information About Carbohydrate Deficient Transferrin (CDT) Test And Links To Where To Get A Blood Test


  • Medical assessment, alcohol consumption, transferrin:How long should you abstain from alcohol before a CDT test? It is generally recommended to abstain from alcohol for at least two weeks before a CDT test to obtain accurate results.
  • What is a CDT test for?It is a blood test used in Driving licence fitness-to-drive medical assessments of alcohol consumption 
  • A CDT (Carbohydrate-Deficient Transferrin) test is used to measure the levelsof a specific protein in the blood that indicates heavy or chronic alcohol consumption over a prolonged period. It helps in assessing alcohol-related health risks and monitoring alcoholism treatment.
  • What is CDT for alcoholism?CDT (Carbohydrate-Deficient Transferrin) is a biomarker used to identify and monitor alcoholism. Elevated CDT levels in the blood indicate heavy or chronic alcohol consumption, and it can be helpful in diagnosing alcohol abuse disorders.
  • What is a CDT blood test UK?A CDT blood test in the UK is a laboratory analysis that measures the levels of Carbohydrate-Deficient Transferrin (CDT) in the blood. It is commonly used to assess alcohol consumption patterns and alcohol-related health risks.1.6% or less would satisfy a Magistrates Court or the DVLA of no recent alcohol intake, but ove 1.7 suggests there is recent or ongoing abuse. %How long do I have to stop drinking before DVLA medical? The Driver and Vehicle Licensing Agency (DVLA) in the UK does not specify a specific duration for alcohol abstinence before a medical assessment. However, it is generally recommended to abstain from alcohol for at least 48 hours before the medical examination to ensure accurate results.
  • Does binge drinking affect CDT levels?Yes, binge drinking can temporarily elevate CDT levels. However, CDT is more indicative of sustained heavy alcohol consumption over an extended period rather than occasional binge drinking episodes.
  • Does smoking raise CDT levels?No, smoking does not significantly affect CDT levels. CDT is primarily influenced by alcohol consumption and is not directly associated with smoking habits.
  • How long does alcohol stay in blood?The duration alcohol stays in the blood varies depending on various factors such as the amount consumed, individual metabolism, and liver function. On average, alcohol can be detected in the blood for up to 12 hours after the last drink, but it can be longer in some cases.


·       Medichecks

·       Atkinson Lewis

·       AlphaBiolabs

·       DrinkDriving.org – DVLA Medical

·       DVLA Medical Questionnaire