A blood clot is a clump of material your blood makes to plug up the bleeding from a cut. Blood clots are made of special clotting substances and platelets (very small blood cells).
After a cut heals, other substances in your blood dissolve the blood clot. Your blood has many different substances that work together to make and dissolve blood clots.
What is excessive clotting?
Excessive clotting is when your blood clots too easily or too much. Blood clots are good when they stop bleeding after an injury. But blood clots that happen when you're not bleeding can be dangerous.
Blood clots may form in your blood vessels when they're not supposed to
The blood clots may make your arm or leg swell up or cause a stroke Stroke A stroke is a sudden brain problem that happens when a blood vessel in your brain either gets blocked or breaks open and bleeds. Part of your brain stops getting blood. Brain tissue that doesn't... read more or heart attack Heart Attack A heart attack is when blood flow to part of your heart is suddenly blocked and some of your heart muscle dies. Doctors use the term myocardial infarction to refer to a heart attack. Myocardium... read more
Sometimes, clots break loose and float through your bloodstream and block blood vessels in another part of your body
Doctors do blood tests to measure the clotting substances and platelets in your blood
You may need to take a blood-thinning medicine to prevent clotting
What causes excessive clotting?
Usually, there's a problem with one of the clotting substances in your blood:
Sometimes, one of your clotting substances is overactive
Sometimes, one of the substances that dissolve blood clots is underactive
The problem is usually something that runs in your family
Sometimes, an illness such as cancer or a problem with your body's immune system Overview of the Immune System The immune system is your body's defense system. It helps protect you from illness and infection. The immune system's job is to attack things that don’t belong in your body, including: Germs... read more makes your clotting substances too active
Other factors increase the risk of excessive clotting:
Being unable to move around enough, such as if you're on bed rest or during a long car or plane ride
Having major surgery, particularly if it involves your lower body
Being pregnant or taking birth control pills
What are the symptoms of excessive clotting?
You don't usually have problems until you're an adult.
If you have excessive clotting in your veins, you may have:
Leg pain and swelling from a clot in your leg (deep vein thrombosis Deep Vein Thrombosis (DVT) Deep vein thrombosis is the formation of blood clots (thrombi) in the deep veins, usually in the legs. Blood clots may form in veins if the vein is injured, a disorder causes the blood to clot... read more )
Shortness of breath or chest pain from a blood clot that travels to your lungs (pulmonary embolism Pulmonary Embolism (PE) Pulmonary is a medical word that refers to the lungs. An embolism is a clump of material (usually a blood clot) moving through your bloodstream. An embolism usually gets stuck when it gets to... read more )
If you have excessive clotting in your arteries, you may have:
How will doctors know if I have excessive clotting?
Your doctor will suspect a clotting problem if you get blood clots and don't have any other problems known to cause blood clots, like cancer or major surgery.
Doctors will ask if you’ve had clots before and if clotting problems run in your family
They’ll do blood tests to measure clotting substances and platelets
How do doctors treat excessive clotting?
Treatment depends on where the clots are, but generally doctors will:
Have you take blood thinners
Make sure you do things to lower your risk of more clots, including stopping smoking and losing weight
Treat any medical problems that raise your risk of excessive clotting