My Mum takes Blood Thinners as instructed by her doctor and she is always telling me that if her blood gets too thin and she gets a small cut she could bleed to death.

I know that when we get a cut sticky blood cells called platelets are used to prevent an extended amount of blood loss from the wound, so how do Blood Thinners prevent this?

  • As Pobrecita stated in their answer there are several types of medicines which can inhibit coagulation or break down a thrombus and they have different mechanisms of action. For a more targeted answer it would help a lot if we knew which medicine/medicine group we were talking about. Thanks! – Lucky Jun 25 '16 at 17:33
  • In general, people taking anticoagulants don't die from small cuts. It's bleedings in the skull and abdomen we're mostly worried about, but even that risk can be acceptable depending on the risk of thrombosis (i.e. the indication) – Jasper Feb 27 '17 at 11:57

There are 2 types of blood thinners anticoagulants and antiplatelets. Simply:


Anticoagulants work by interrupting the process involved in the formation of blood clots. They're sometimes called "blood-thinning" medicines, although they don't actually make the blood thinner


Vitamin K is essential for those reactions. Warfarin (Coumadin) works by decreasing the activity of vitamin K; lengthening the time it takes for a clot to form.


Antiplatelet drugs, such as aspirin, prevent blood cells called platelets from clumping together to form a clot.

A deeper understanding can be derived from looking up the individual medications: Clopidogrel (Antiplatelet) and Coumadin(Anticoagulant). I don't know which type your refering to, but they:

Anticoagulant and antiplatelet drugs work by stopping platelets from adhering to one another and clotting proteins from binding together.

  • Blood thinners can cause thrombocytopenia (low platelets). However, the platelets have to be severely low beneath 100,000 to cause spontaneous and uncontrollable bleeding that may cause death usually.

Many medications can cause low platelet count by causing immunologic reaction against platelets, called drug-induced thrombocytopenia.

So basically on this stuff it takes you longer to clot and therefore increased the time you bleed.

  • The new oral anticoagulants render this answer dated and incomplete. They don't work by affecting platelets or vitamin K function, and they are quickly supplanting warfarin and aspirin as anticoagulants for most purposes. – Carey Gregory Nov 29 '16 at 21:26

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.