When you get a cut, your body stops the bleeding by forming a blood clot, which is a thickened mass of blood tissue. Substances in your blood called proteins work with tiny particles called platelets to form the clot. Forming a clot is called coagulation. Coagulation helps when you are injured because it slows blood loss. However, your blood shouldn't clot when it's moving through your body inside your blood vessels. The tendency to clot too much is called hypercoagulation (say: hi-per-co-ag-u-lay-shun). It can be very dangerous.
Certain proteins in your blood are supposed to keep your blood from clotting too much. Some people do not have enough of these proteins. In other people, these proteins are not doing their job properly, or there may be extra proteins in the blood that causes too much clotting.
Some people are born with a tendency to develop clots. This tendency is inherited (which means it runs in your family).
Certain situations or risk factors can make it more likely for your blood to clot too much. These situations include the following:
You may be at risk of hypercoagulation if any of the following are true:
If your doctor suspects you have hypercoagulation, tests can check the protein levels in your blood. The tests will also show if your proteins are working the way they should to properly clot your blood.
Yes. Several medicines can thin your blood and make it less likely to clot. Some people with hypercoagulation only need to take blood thinners when they're in a situation that makes them more likely to form clots (such as when they are in the hospital recovering from surgery, when they are in a car or airplane for a long time or when they are pregnant). Other people need to take medicine on an ongoing basis for the rest of their lives. Your doctor will decide what treatment is right for you.
The two most common blood thinners are called heparin and warfarin. Your doctor will probably give you heparin first, because heparin works right away. Heparin must be injected with a small needle under the skin. Once the heparin begins to work, your doctor will probably have you start taking oral warfarin. Warfarin takes longer to begin working.
Both medicines can cause you to bleed more easily. If you cut yourself, you might notice that the blood takes longer to clot than usual. You might also bruise more easily. Call your doctor if you have any unusual or heavy bleeding.
Warfarin has a stronger effect on some people than on others. If you take warfarin, your doctor will want to check you often with a blood test that shows how well the warfarin is working. Some other medicines can increase or decrease the strength of warfarin. Ask your doctor before you take a new medicine, including over-the-counter medicines, vitamins and herbal supplements. Also, talk to your doctor about foods you should avoid while taking warfarin.
If you're pregnant, you should not take warfarin. Warfarin can cause birth defects. Instead, you must use heparin until you deliver your baby. If you want to get pregnant and you're already taking warfarin, talk with your doctor about changing to heparin. Sexually active women who take warfarin should use birth control.
A clot inside a blood vessel is called a thrombus. Sometimes the thrombus can travel in the bloodstream and get stuck in your lungs. This kind of clot (called a pulmonary embolus) blocks blood from getting to your lungs. A pulmonary embolus can be life-threatening.
A clot that blocks a blood vessel in the brain can cause a stroke. A clot in a blood vessel in the heart can cause a heart attack. Blood clots can cause some women to have miscarriages. All of these conditions can also be life-threatening.
Written by familydoctor.org editorial staff