What Are the Signs of a Blood Clot?

Having a blood clot can be an unpredictable and life-changing event. Each year, nearly one million Americans are affected by deep vein thrombosis (DVT), just one type of clot, says the American Society of Hematology. You can't self-diagnose blood clots, but if you're aware of the common symptoms and health risks, you will be more likely to know if and when to talk to your doctor.

What Is a Blood Clot?

Blood clots are jellylike clusters of blood that develop when platelets and plasma proteins thicken to stop bleeding caused by an injury, cut, or damage to a blood vessel. Essentially, they act like plugs, and when the injured area is healed, the body reabsorbs the clot back into the bloodstream.

Occasionally clots can form without reason or don't dissolve entirely. Many conditions and risk factors can cause blood clots throughout the body. The American Heart Association reports the common risk factors of blood clots include advanced age, family history, a sedentary lifestyle, pregnancy, some birth control pills, fractures or severe muscle injury, major surgery, being a smoker or obese, heart or lung disease, and cancer.

Types and Symptoms

The symptoms of blood clots depend on the type and location of the clot. A clot that stays in place but blocks blood flow is called a thrombus, and an embolus is a clot that breaks free and travels via your circulatory system to other areas. Both have a high potential to become dire medical emergencies. Here are some of the common locations and their symptoms.

• Leg: DVT is a clot in the deep veins of the thighs and calves that causes pain, redness, and inflammation. It can break off and travel to the heart, lungs, or brain.
• Arm, leg, or feet: An arterial embolism is a clot in an artery affecting the arms, legs, or feet that can cause pain, pale color, and coolness to the touch.
• Intestines: Acute mesenteric ischemia is a blood clot in an artery supplying blood to the intestines. These types of clots are common in people with an irregular heartbeat or heart disease and cause sudden abdominal pain, nausea, and vomiting.
• Lung: Pulmonary embolism occurs when a blood clot, usually resulting from a DVT, prevents blood flow to the lungs, causing chest pain, coughing, shortness of breath, and rapid pulse.
• Brain: An ischemic stroke occurs when a clot forms in an artery that supplies blood flow to the brain, causing tissue damage or death. Symptoms include loss of speech, vision, and weakness on one side of the body.
• Heart: A heart attack can be caused by a blood clot in a coronary artery, leading to chest pain, shortness of breath, sweating, and nausea.

Treatment and Prevention

Diagnosing blood clots can be difficult — according to the CDC, nearly 50 percent of people with DVT show no symptoms. So, if you develop swelling, redness, or pain in your arm or leg, call your doctor immediately. They can examine you and order additional tests — like a noninvasive ultrasound of your veins and/or arteries — to establish the exact cause of concern and make a diagnosis.

There are many ways to prevent and treat blood clots. Lifestyle changes like quitting smoking, maintaining a healthy weight, staying physically active, and eating a heart-healthy diet can lower your blood clot risks. Blood thinners (anticoagulants) or other medications can help to dissolve a clot that's already formed.

Talk to your doctor about how to improve your well-being and lower your chances of future blood clots.