Question: how do blood clots happen ?

Amy MacQueen answered on 10 Jun 2011:

Hey!

Right..say you bumped into someone on the stairs in school and you tripped and fell. You put out your hand to save yourself and you graze it on the floor. What happens? Well you start bleeding – the blood that comes out has red blood cells (hence the colour!), white blood cells and tiny little things called platelets. These platelets gather around the graze wound and interact with other things in the blood plasma (liquid) to form long sticky threads called fibrin which crisscross each other and form a sort of dam to stop the blood flowing out. Eventually this dam turns into a scab.

So why don’t we have blood clotting in our bodies all the time? well when we get cut the damage causes our cells to release special signals to attract the clotting factors and platelets and tell them to form a clot.

But some people do get clots in places they shouldn’t be and this can be dangerous – how does this happen? Well if you sit still for long periods of time (like really long plane journeys) your blood is moving slower and this allows it to clot more easily. If you have had an operation or damage to your blood vessels (like during a heart attack for example) then you can get a clot inside you from blood clotting around the damaged tissue. Some medication can also make you more likely to get blood clots. These clots can be dangerous because they can break off and move around the body in your blood and get stuck somewhere else – blocking the blood flow in places like the lungs or the brain.
But you shouldn’t worry about getting blood clots where you don’t want them – it’s not very common in young people and if you make sure you eat well, do lots of exercise and don’t smoke or drink a lot then you are not very likely to get them when you are old either!

And after all you DO want your blood to clot when you fall on the stairs…its a pretty neat system!
See ya later, if there’s anything you don’t understand just message me back!

Amy 😀