Skip to content

Deep Vein Thrombosis Health Center

Font Size
A
A
A

Blood Clots

Blood has a seemingly impossible job: It must flow continuously and smoothly throughout your body for an entire lifetime, but quickly shut off to prevent spills when you get a cut or injury.

Blood clots are healthy and lifesaving when they stop bleeding. But they can also form when they aren't needed and cause a heart attack, stroke, or other serious medical problems.

Recommended Related to DVT (Deep Vein Thrombosis)

Taking Blood Thinners for Deep Vein Thrombosis (DVT)

Blood thinners (also called anticoagulants) are commonly used to treat deep vein thrombosis (DVT) usually in the upper part of the leg. Though they're called blood thinners, these DVT treatments do not actually thin your blood. Instead, they keep existing blood clots from getting larger or prevent new ones from forming. They do this by preventing the production of certain proteins needed for blood to clot. Common blood thinners include: Apixaban (Eliquis) Dabigatran (Pradaxa) Edox...

Read the Taking Blood Thinners for Deep Vein Thrombosis (DVT) article > >

How Does Blood Clot?

The life cycle of a normal blood clot depends on a series of chemical interactions.

1. Platelets form a plug. Tiny bits in your blood called platelets get "turned on" by triggers released when a blood vessel is damaged. They stick to the walls in the area and each other, changing shape to form a plug that fills in the broken part to stop blood from leaking out.

When activated, platelets also release chemicals to attract more platelets and other cells, and to set off the next step.

2. The clot grows. Proteins in your blood called clotting factors signal each other to cause a rapid chain reaction. It ends with a dissolved substance in your blood turning into long strands of fibrin. These get tangled up with the platelets in the plug to create a net that traps even more platelets and cells. The clot becomes much tougher and more durable.

3. Reactions stop its growth. Other proteins offset extra clotting factor proteins so the clot doesn't spread farther than it needs to.

4. Your body slowly breaks it down. As the damaged tissue heals, you don't need the clot any more. The tough fibrin strands dissolve, and your blood takes back the platelets and cells of the clot.

What Causes Blood Clots?

The process begins whenever flowing blood comes into contact with specific substances in your skin or in blood vessel walls. When they touch, it usually means the skin or blood vessel wall is broken.

Waxy cholesterol plaques that form in arteries have these things inside, too. If the plaque breaks open, they'll start the clotting process. Most heart attacks and strokes happen when a plaque in your heart or brain suddenly bursts.

Blood clots can also form when your blood doesn't flow properly. If it pools in your blood vessels or heart, the platelets are more likely to stick together. Atrial fibrillation and deep vein thrombosis (DVT) are two conditions where slowly moving blood can cause clotting problems.

Today on WebMD

TAG dvt blood clot
Symptoms, causes, risk factors, and more.
businesswoman in airport
Tips to prevent another clot.
 
blood thinners
Tips for DVT.
Blood clots in artery
Causes and treatments.
 
Simple Steps to Lower Cholesterol
Slideshow
Having Surgery Tips To Reduce DVT Risk And More
Slideshow
 
New DVT Therapies On The Horizon
Video
Atrial Fibrillation Guide
Slideshow
 

WebMD Special Sections