Blood clots are gel-like clumps of blood. They are beneficial when they form in response to an injury or a cut, plugging the injured blood vessel, which stops bleeding.
Some blood clots form inside your veins without a good reason and don't dissolve naturally. These may require medical attention, especially if they are in your legs or are in more critical locations, such as your lungs and brain. A number of conditions can cause this type of blood clot.
Blood clots form when certain parts of your blood thicken, forming a semisolid mass. This process may be triggered by an injury or it can sometimes occur inside blood vessels that don't have an obvious injury.
Seek emergency care if you experience:
- Cough that produces bloody sputum
- A fast heartbeat
- Difficult or painful breathing
- Chest pain or tightness
- Pain extending to your shoulder, arm, back or jaw
- Sudden weakness or numbness of your face, arm or leg
- Sudden difficulty speaking or understanding speech (aphasia)
- Sudden changes in your vision
Consult your doctor if you develop these signs or symptoms in an area on an arm or leg:
To reduce your risk of developing blood clots, try these tips:
- Avoid sitting for long periods. If you travel by airplane, walk the aisle periodically. For long car trips, stop and walk around frequently.
- Move. After you've had surgery or been on bed rest, the sooner you get up and move around, the better.
- Drink plenty of fluids when traveling. Dehydration can contribute to the development of blood clots.
- Change your lifestyle. Lose weight, lower high blood pressure, stop smoking and exercise regularly.
May 29, 2020
- Blood clots. American Society of Hematology. http://www.hematology.org/Patients/Blood-Disorders/Blood-Clots/5233.aspx. Accessed April 18, 2016.
- Your guide to preventing and treating blood clots. Agency for Healthcare Research and Quality. http://www.ahrq.gov/patients-consumers/prevention/disease/bloodclots.html. Accessed April 18, 2016.
- Longo DL, et al., eds. Bleeding and thrombosis. In: Harrison's Principles of Internal Medicine. 19th ed. New York, N.Y.: McGraw-Hill Education; 2015. http://accessmedicine.com. Accessed April 18, 2016.
- Understand your risk for excessive blood clotting. American Heart Association. http://www.heart.org/HEARTORG/Conditions/More/Understand-Your-Risk-for-Excessive-Blood-Clotting_UCM_448771_Article.jsp. Accessed April 18, 2016.
- What causes excessive blood clotting? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/ebc/causes. Accessed April 18, 2016.
- Barbara Woodward Lips Patient Education Center. Preventing blood clots in the veins and lungs. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2012.
- Longo DL, et al., eds. Arterial and venous thrombosis. In: Harrison's Principles of Internal Medicine. 19th ed. New York, N.Y.: McGraw-Hill Education; 2015. http://accessmedicine.com. Accessed April 18, 2016.
- Papadakis MA, et al., eds. Blood vessel & lymphatic disorders. In: Current Medical Diagnosis & Treatment 2016. 56th ed. New York, N.Y.: The McGraw-Hill Companies; 2016. http://accessmedicine.com. Accessed April 18, 2016.
- Lip G, et al. Overview of the treatment of lower extremity deep vein thrombosis (DVT). http://www.uptodate.com/home. Accessed April 18, 2016.
- AskMayoExpert. COVID-19: Myocardial injury (adult). Mayo Clinic; 2020.