Does alcohol use disorder cause thrombosis (blood clots)?

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Last updated: March 9, 2025View editorial policy

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From the Guidelines

Alcohol use disorder can contribute to an increased risk of thrombosis, particularly in cases of excessive consumption, due to its effects on liver function, inflammation, and blood clotting factors. The relationship between alcohol consumption and thrombosis is complex, with moderate alcohol intake potentially reducing platelet aggregation and providing an antithrombotic benefit, as suggested by studies such as 1 and 1. However, excessive alcohol consumption can lead to liver damage, which impairs the production of proteins essential for normal blood clotting, potentially resulting in both bleeding problems and increased clot formation. Chronic heavy drinking also causes inflammation throughout the body, including blood vessel walls, making them more prone to clot formation. Additionally, alcoholism raises levels of fibrinogen, a protein involved in clot formation, and can increase platelet activation and aggregation.

Key factors to consider in the relationship between alcohol use disorder and thrombosis risk include:

  • The level of alcohol consumption, with excessive intake being more likely to contribute to thrombosis risk
  • The presence of comorbid conditions such as high blood pressure, diabetes, or poor nutrition, which can independently increase clotting risk
  • The potential for alcohol withdrawal to trigger a hypercoagulable state
  • The importance of reducing alcohol consumption and seeking professional help for safe withdrawal and treatment of underlying addiction for those concerned about blood clot risk related to alcohol use. According to 1, excessive alcohol intake increases the risk of bleeding, but the context of thrombosis risk suggests that the balance between bleeding and clotting risks needs careful consideration.

Given the potential for alcohol use disorder to contribute to thrombosis risk, reducing alcohol consumption is advisable for individuals concerned about blood clot risk, and those with alcoholism should seek professional help for safe withdrawal and treatment of the underlying addiction. This approach prioritizes minimizing morbidity, mortality, and improving quality of life by addressing the underlying factors that contribute to thrombosis risk in the context of alcohol use disorder.

From the Research

Association Between Alcohol Use Disorder and Thrombosis

  • The relationship between alcohol use disorder and thrombosis is complex, with some studies suggesting a decreased risk of venous thrombosis associated with moderate alcohol consumption 2.
  • A study published in the Journal of Thrombosis and Haemostasis found that alcohol consumption was associated with a reduced risk of venous thrombosis, with 2-4 glasses per day resulting in the largest beneficial effect 2.
  • Another study found that chronic alcohol consumption was associated with a low risk of deep vein thrombosis (DVT) in trauma patients 3.
  • However, the effects of alcohol on coagulation and fibrinolytic factors are not entirely clear, with some studies suggesting that alcohol intake may decrease plasma fibrinogen and increase factor VII and plasminogen activator inhibitor-1 (PAI-1) 4.

Effects of Alcohol on Coagulation and Fibrinolytic Factors

  • Alcohol intake has been shown to decrease plasma fibrinogen, which may contribute to the apparent protection against ischemic coronary and cerebral events 4.
  • However, alcohol intake may also increase factor VII and PAI-1, which could attenuate the beneficial effects of alcohol on coagulation and fibrinolysis 4.
  • The balance of anticoagulant and procoagulant and fibrinolytic effects in individuals may vary depending on the quantity and type of alcoholic beverage ingested, as well as genetic and other variables 4.

Risk of Pulmonary Embolism and Deep Vein Thrombosis

  • A study published in the Journal of Thrombosis and Haemostasis found that alcohol consumption was not associated with an increased risk of pulmonary embolism (PE) 5.
  • Another study found that the prevalence of DVT was lower in alcoholics compared to non-alcoholics, although the overall incidence of PE was not significantly different between the two groups 3.
  • A study published in Thrombosis and Haemostasis found that alcohol consumption was associated with a reduced risk of venous thrombosis, which may be in part mediated by decreased fibrinogen levels 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The effects of alcohol on coagulation and fibrinolytic factors: a controlled trial.

Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, 1998

Research

Alcohol consumption and the risk of incident pulmonary embolism in US women and men.

Journal of thrombosis and haemostasis : JTH, 2018

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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