A blood clot in the upper arm is not life-threatening unless it breaks free and becomes lodged in the lung, according to Cleveland Clinic. Blood clots are produced by the body to plug holes in veins in response to an injury. Sometimes these clots become lodged in a vein. If clots become trapped in a vein deep within the body, it is called deep vein thrombosis, or DVT. Deep vein thrombosis usually occurs in the thighs and lower legs but DVT in the upper arm still poses a threat of traveling to the lungs where it could cause the deadly condition known as pulmonary embolism.
No Symptoms
More than half of the people with deep vein thrombosis have no symptoms at all, according to Merck Manuals Online Medical Library. In cases in which the clot has traveled to the lung, the shortness of breath associated with a pulmonary embolism is the first sign that something is wrong.
Pain
A blood clot in the upper arm can cause tenderness and pain in the arm or neck. This symptom is caused by the increased pressure on the vein and lack of blood flow to tissue.
Swelling
Swelling in the arm or neck can be a sign of a blood clot. This swelling may occur suddenly soon after the clot becomes trapped or swelling may come on slowly and become permanent if the affected vein is destroyed.
Redness
Redness may occur near the site of the blood clot, according to MayoClinic.com. The blood clot may be partially or completely blocking the vein, causing a backlog of blood in the arm. There may even be a bluish skin discoloration near the affected area of the arm. This is caused by blood cells escaping the damaged vein and leaking into the surrounding tissue.
Warmth
Increase in temperature when compared to the other arm. It is easier for a second person to touch both arms at the same time to detect if one is warmer than the other.
Bulging veins
Enlargement of veins close to the surface of the skin is caused by blood backing up in the arm because blood cannot get past the clot. A clot in the upper arm may cause bulging of the veins in the hand and lower arm.
Discolored skin
Eventually, if the clot does not dissolve or become dislodged, it may become covered in scar tissue. This destroys the vein and the surrounding tissue which may become oxygen starved and die. Dry, discolored skin may be noticed on the arm.
Superficial clot
A clot in a vein close to the surface of the arm usually causes symptoms similar to deep vein thrombosis. A superficial clot, also called superficial thrombophlebitis, does not usually cause the same complications as deep vein thrombosis but pulmonary embolism is still possible, according to MedlinePlus.
