A blood clot, or thrombus, occurs when blood coagulates as part of hemostasis. There are two components in a blood clot: the red blood cells forming a plug and aggregated platelets. When the clot occurs, there is a mesh of cross-linked fibrin protein.
In normal cases, a blood clot is a healthy response to injuries as it functions to prevent excessive bleeding. However, when it occurs in a blood vessel, it can be dangerous as the clot obstructs the flow of blood to the other healthy blood vessels. Causes of a blood clot formation can be attributed to endothelial injury, blood stasis, and hypercoagulability.
Blood clots occur less commonly in arms and legs. Only 10 percent of blood clots involving deep veins occur in the arms. It is important to recognize blood clot symptoms as it helps you to seek immediate medical attention.
Symptom #1: Swelling
Swelling is most evident when the blood clots occur in the deep veins. The clots are usually located in the subclavian and axillary veins. These large veins are veins that extend through the upper arm, going through the armpit, shoulder, and into the chest. These veins are important as they carry most of the blood from the arm back to the heart. When there is obstruction, the blood is unable to flow back to the heart and results in obvious swelling of the arm and hand.
If the blood clot occurs in the superficial vein, the swelling is usually localized and can be attributed to the inflammation of the vein. In arterial blood clots, swelling is uncommon and usually appears when there is extensive cell death.