Conversation: The conversation between human and AI assistant.
[|Human|] Why does my blood tend to clot quickly? I went to take a test and the nurse was injecting something into my vein. When she found the vein and pulled the vhamber back blood came in and then she lost it. Within minutes the blood that was already in the syringe clogged the needle and she had to take it out. Is that normal? Sincerely, Kelly
[|AI|]  Hello and welcome to Chat Doctor, While blood is being taken out from any blood vessel, it is important to transfer blood in appropriate anti-coagulant to prevent its clotting. However, when the time elapsed between taking out blood in syringe and transferring it to appropriate container with anti-coagulant is long enough, the blood will clot. Blood will clot if it does not contact with an anti-coagulant within time. Thus, clotting of blood is not an abnormality. However, if the clotting time is increased or decreased then it is an abnormality. You can get bleeding and clotting time to assess the functioning of coagulation system. Thanks and take care Chat Doctor.