The signs and symptoms of a blood clot vary with the location of the clot—whether it's in a vein or an artery—and its size. They can include swelling, skin tenderness and warmth, and even chest pain, shortness of breath, and dizziness. The severity of symptoms also varies depending on their cause.

When symptoms indicate a heart attack or stroke, it is critical to get immediate attention.

blood clot symptoms — Illustration by Verywell

Frequent Symptoms

It is possible to have a blood clot and not experience symptoms (as with pulmonary hypertension or a clot in the kidney). But more often than not, blood clots in major veins or arteries will cause symptoms, often serious ones that require immediate attention.

Blood clots can occur in different veins and arteries throughout the body, and symptoms are specific to where they are located.

Symptoms of a blood clot indicating deep vein thrombosis (DVT) include:

Warmth in the area of the clot
Swelling, possibly making one leg larger than the other
Tenderness when you touch the area around the clot
Mild to moderate pain that increases over hours or days

Symptoms of a blood clot that may suggest a heart attack:

Chest pain or discomfort: Most heart attacks involve discomfort in the center or left side of the chest. The discomfort usually lasts for more than a few minutes or goes away and comes back. It can feel like pressure, squeezing, fullness, or pain. It also can feel like heartburn or indigestion.
Upper body discomfort: You may feel pain or discomfort in one or both arms, the back, shoulders, neck, jaw, or upper part of the stomach.
Shortness of breath: This may be your only symptom, or it may occur before or along with chest pain or discomfort. It can occur when you are resting or doing a little bit of physical activity.
Breaking out in a cold sweat
Feeling unusually tired for no reason, sometimes for days (especially if you are a woman)
Nausea and vomiting
Lightheadedness or sudden dizziness

Symptoms of a blood clot that may suggest a stroke:

Sudden weakness or numbness in the face, arm, or leg on one side of the body
Sudden loss, blurring, or dimming of vision
Slurred speech or inability to speak
Sudden, severe headache
Dizziness, drowsiness, falling, or lack of coordination
Nausea or vomiting, especially if accompanied by any of the above symptoms

Complications and Sub-Groups

Blood clots can, but don’t always, cause the following complications. You may or may not experience any of the common symptoms of a clot before these occur, if they do:

Pulmonary embolism: Sometimes a clot in the limbs or pelvis (DVT) breaks loose and travels to the lungs, obstructing the flow of blood to the lung. Symptoms include sudden, severe shortness of breath, rapid breathing, chest pain, profuse sweating, loss of consciousness, bluish color to the lips and fingertips, and a cough that may produce bloody sputum (mucus).

Pulmonary hypertension: It is possible to have several blood clots that block smaller pulmonary arteries yet cause no symptoms. This can lead to high blood pressure in the pulmonary arteries, which, in turn, puts extra stress on the heart, potentially resulting in heart failure.

Several health conditions, including diabetes and atherosclerosis, increase the risk of developing a blood clot, as does being a smoker. It is especially important to be on the alert if you use birth control pills, are pregnant or postpartum, on hormone replacement therapy (HRT), or have recently had surgery.

When to See a Doctor

If you have symptoms of DVT, call your doctor right away. If symptoms suggest a heart attack, stroke, or pulmonary embolism, call 911 or go to the emergency room, as these are life-threatening conditions.