clotting

clotting /clot·ting/ (klot´ing) coagulation (1).

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clotting.

See blood clotting.

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clotting

the formation of a jellylike substance over the ends or within the walls of a blood vessel, with resultant stoppage of the blood flow. Clotting is one of the natural defense mechanisms of the body when injury occurs. A clot will usually form within 5 minutes after a blood vessel wall has been damaged. The clotting mechanism is triggered by the platelets, which disintegrate as they pass over rough places in the injured surface. As they disintegrate they release serotonin and thromboplastin. Serotonin causes constriction of the blood vessels and reduction of local blood pressure. Thromboplastin unites with calcium ions and other substances which promote the formation of fibrin. When examined under a microscope, a clot consists of a mesh of fine threads of fibrin in which are embedded erythrocytes and leukocytes, small amounts of fluid (serum), and platelets.

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clotting defects

see coagulopathy.

clotting factors

a series of plasma proteins which are related through a complex cascade of enzyme-catalyzed reactions involving the sequential cleavage of large protein molecules to produce peptides, each of which converts an inactive zymogen precursor (factor II) into an active enzyme (Iia) leading to the formation of a fibrin clot. They are designated by Roman numerals, and an additional 'a' to indicate the activated state. They are: factor I (fibrinogen), factor II (prothrombin), factor III (tissue thromboplastin), factor IV (calcium), factor V (proaccelerin), factor VI (no longer considered active in hemostasis), factor VII (proconvertin), factor VIII (antihemophilic factor), factor IX (plasma thromboplastin component; Christmas factor), factor X (stuart factor), factor XI (plasma thromboplastin antecedent), factor XII (hageman factor), factor XIII (fibrin stabilizing factor).

clotting time

the time required for blood to clot in a glass tube; a measure of the intrinsic system of coagulation. In the Lee-White method, blood in test tubes is maintained at a constant temperature and examined regularly until clotting occurs; the test can be also be performed in capillary tubes. Called also coagulation time. Less sensitive and now less often used than the activated coagulation time.

tissue clotting factor

clotting factor III; tissue thromboplastin.

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Patient discussion about clotting.

Q. How can I prevent blood clots? I am 45 years old and am supposed to go on a business trip overseas. The flight itself is 12 hours long and then I have to continue traveling by bus. Could this cause me to have blood clots? If so, how can I prevent it?

A. Sitting or laying in one position for a long period of time can increase the risk of developing DVT- deep vein thrombosis. Here are some methods to prevent it:
Exercise your calf and foot muscles regularly:
Every half hour or so, bend and straighten your legs, feet and toes when you are seated.
Press the balls of your feet down hard against the floor or foot-rest every so often. This helps to increase the blood flow in your legs
Take a walk up and down the aisle every hour or so, when the aircraft crew say it is safe to do so.
If you are allowed, get off the plane and walk about if the plane stops for refueling.
Consider buying a leg exerciser for the journey.
Drink plenty of water (to avoid dehydration).
Do not drink too much alcohol. (Alcohol can cause dehydration and immobility.)
Do not take sleeping tablets, which cause immobility.
Consider wearing compression stockings.
Some people at high risk may also be advised to take anticoagulant medication by their Dr.

Q. very dark blood clots @ first sight of period? At first sight of period, instead of normal rosy spotting it's brownish spotting followed by small clots.

A. Hi Bonbolong.. I just need to ask you a few questions before I feel I can answer you to the best of my ability..Are you now, or have you ever been on birth control pills? How old are you? Have your periods always been like this? When I was young I had so many problems with my periods I wanted a hysterecomy. Of course at 14 years ols, my doctor wouldnt listen..LOL.. I would call your doctor just so he/she can assure you that you are ok..You said your blood was a browish color, I wouldnt worry about that, it is when the blood is black that means something is going on. DOnt worry abou t the clots, that is normal. Like I said, I had many problems when I was young, in fact my GYN had me on birth control at 14 years old. I hope I helped a little, but please get in touch with your doctor, it is amazing how much better you will feel when you find out you are fine

Shirley

Q. What causes blood clots? My father had a heart attack which was caused by a blood clot. Am I at risk for developing blood clots too? How do I prevent it from happening?

A. I found a website that checks your risks for inheriting your family's illness, including blood clots. They have a test you can do which is called "Free Risk Assessment for Thrombophilia":
http://www.dnadirect.com/patients/tests/blood_clotting/more_about/GH_Thr_Risk.jsp