Unilateral upper limb edema refers to the swelling of the soft tissues of either the right or left arm or hand. Edema is more common in the legs and feet. If it occurs in the upper extremity, it is usually due to problems with drainage of the blood or lymph from the arm.
Deep Vein Thrombosis
A deep vein thrombosis is a blood clot in one of the deep veins of the arms. They are more common when the limb is immobile for long periods of time. Some inherited blood disorders that predispose a person to clotting and some other diseases such as cancer. The blood clot impedes the return of blood to the heart from the arm, and fluid leaks out of the blood vessels into the tissues.
SVC syndrome is the abbreviation for superior vena cava syndrome. The superior vena cava is the vein that drains blood from the upper body back to the heart. In SVC syndrome, the vein is narrowed. The typical culprit is cancer. For example, the right lung abuts the superior vena cava. Lung cancer growing near the vein can compress it, causing blood to back up into the arm. In addition, the slow flowing blood can can cause blood to clot in an arm.
The lymphatic system drains fluid from the tissues and returns it to the venous system. Any disorder that interferes with the drainage of lymphatic fluid from the arm will cause unilateral upper extremity edema. In breast cancer, the lymph nodes of the arm and chest wall may be removed during surgery to look for the spread of cancer. Radiation therapy can also damage the lymph nodes. Cancer cells can spread to the lymphatics and interfere with the flow of lymphatic fluid. Infections, typically with parasites, can do the same.
Reflex Symphathetic Dystrophy
Reflex sympathetic dystrophy is also known as complex regional pain syndrome. It is a rare disorder characterized by dysfunction of the nerves and blood vessels in the affected area. It can cause intense burning pain and sensitivity. It often occurs after trauma. In addition to pain, the affected limb may change color, swell with fluid and have limited motion.