A blood clot is a gel-like clump of blood.
Blood clots form when blood hardens from a liquid to a solid. Usually, a blood clot forms when you are cut or injured. Blood clots help stop the bleeding from an injury by plugging an injured blood vessel.
Blood clots can also form inside veins without a cut or injury. When a blood clot forms without a good cause and does not dissolve naturally, it may require medical attention.
Vascular care at WashU Medicine
Vascular surgeons at WashU Medicine see patients at Barnes-Jewish Hospital, one of the top hospitals in the nation for heart and vascular care, as well as convenient locations across the St. Louis area. Our team has expertise in minimally invasive procedures to treat vascular problems ranging from common to complex.
What is a blood clot?
A blood clot is a mass of blood cells that forms in your blood vessels. Blood clots can protect your body from bleeding too much by blocking the flow of blood from a cut or injury. Blood clots that form to prevent excessive bleeding after an injury can be normal, and are often nothing to worry about for many people.
People with certain medical conditions may develop blood clots inside their veins and arteries, even when they are not injured. These blood clots can cause symptoms and can be life- threatening.
What is a thrombus?
A blood clot that forms inside a vein or artery is called a thrombus.
When a blood clot forms in the arteries, it is called arterial thrombosis.
Arterial thrombosis is often linked to heart attacks and strokes.
When a blood clot forms in the veins, it is called venous thrombosis.
Venous thrombosis can cause deep vein thrombosis (DVT) or pulmonary embolism (PE).
Causes and risk factors
Blood clots can form due to many factors. Normal blood clots form in response to injury, such as if you cut yourself shaving. These blood clots are the reason you stop bleeding after a little while.
Blood clots can also form due to:
- Injury to blood vessels
- Prolonged immobility, such as from a long flight or being on bed rest
- Medical conditions including cancer, heart disease, obesity
- Lifestyle factors, such as smoking, being pregnant, or taking certain medications including birth control or hormone therapy
- Genetic factors, such as blood clotting disorders that cause your body to make more blood clots than normal
- Age—people 65 and older are at increased risk
Blood clots vs. deep vein thrombosis: What’s the difference?
Symptoms
Blood clots that form in the veins and arteries (called thrombosis) can produce noticeable symptoms. These may include:
DVT (usually in legs)
- Swelling
- Pain or tenderness
- Warmth and redness
Learn more about deep vein thrombosis (DVT)>>
Pulmonary embolism (in lungs)
- Sudden shortness of breath
- Chest pain (worsening with deep breaths)
- Rapid heartbeat
- Coughing up blood
Symptoms of deep vein thrombosis or pulmonary embolism can be signs of a serious medical emergency requiring immediate medical attention.
Prevention
Some factors cannot be prevented, such as a genetic blood clotting disorder. There are steps people can take to reduce their risk of forming blood clots:
- Seeing your health care provider for regular physical exams
- Maintaining a healthy weight
- Not smoking
- Staying hydrated
- Staying active
- Avoiding prolonged immobility
Read more: 5 ways to improve circulation>>
Frequently asked questions about blood clots
A blood clot is a semi-solid mass of blood that can block blood flow. Blood clotting is a natural process that is not always dangerous. If a blood clot forms in the arteries or veins, then travels to the lungs (pulmonary embolism) or brain (stroke), it can be life-threatening.
Common symptoms include swelling, pain, redness, and warmth in the leg (DVT) or sudden shortness of breath and chest pain (PE). If you suspect you have a blood clot, a health care provider can help diagnose the problem with tests.
Risk factors include prolonged immobility, surgery, trauma, cancer, pregnancy, birth control pills, smoking, obesity, and genetic conditions.
Treatment usually involves anticoagulants (blood thinners) like heparin, warfarin, or newer oral medications. Severe cases may need thrombolytic therapy or surgery. Vascular surgeons at WashU Medicine specialize in minimally invasive procedures for people with blood clots in St. Louis.
The main risk is bleeding. A blood thinner makes it so your blood does not clot, even when it normally should, such as when you get a cut or injury. Other possible effects include hair loss, feeling cold, and interactions with certain foods or medications.
