What is lymphedema?
Lymph is fluid that oozes out of your tiniest blood vessels. The fluid goes between your cells and brings nourishment and carries away damaged cells, cancer cells, and germs. Lymph then travels through tiny tubes called lymphatic vessels. The vessels carry lymph from your tissues to collection points called lymph nodes.
Lymphedema is swelling of an arm or leg because lymph flow is blocked.
Lymphedema usually results from having lymphatic vessels or lymph nodes removed or damaged (such as during surgery or radiation for cancer)
It can rarely result from a birth defect
Lymphedema has no cure, but special massages along with pressure stockings and bandages can help with the swelling
Doctors and nurses avoid drawing blood, taking blood pressure, or starting an IV in an arm or leg with lymphedema
What causes lymphedema?
Lymphedema results when part of your lymphatic system Overview of the Lymphatic System The lymphatic system is a network of lymphatic vessels and lymph nodes that carry fluid called lymph. The lymphatic system is part of your immune system, which helps defend against infection... read more is blocked. Then, lymph builds up in your tissues, causing swelling.
Rarely, children are born without enough lymph vessels.
Usually, your lymph vessels are normal, but something happens that blocks them, such as:
Surgery, such as when doctors remove lymph nodes from the armpit of women having surgery for breast cancer Surgery Cancer is when cells grow abnormally. Cancer cells don't look or work like normal cells and keep multiplying out of control. Cancer cells can invade and destroy nearby healthy tissue. Sometimes... read more
Severe injury to an arm or leg
In developing countries, a certain kind of worm infection called lymphatic filariasis Lymphatic Filariasis Lymphatic filariasis is infection of the lymphatic system caused by one of three species of roundworms. People have a fever, swollen lymph nodes, pain in the limbs and groin, and, if the infection... read more 
causes lymphedema. Rarely, a cancer blocks your lymphatic vessels.
What are the symptoms of lymphedema?
One arm or leg swells up and looks puffy but has a normal color. It may feel tight, but it doesn't hurt. After you've had lymphedema for a while, the skin where the lymphedema is may be a darker brown color than your normal skin.
How can doctors tell if I have lymphedema?
Doctors can tell you have lymphedema by doing a physical exam. Usually, the cause is obvious, like surgery you've had. If doctors aren't sure why you have lymphedema, they may do imaging tests, such as CT (computed tomography) scan Computed Tomography A CT scan uses a large machine shaped like a large donut to take x-rays from many angles. A computer then takes the x-rays and creates many detailed pictures of the inside of your body. Each... read more or MRI Magnetic Resonance Imaging (MRI) MRI is a test that uses a machine with a powerful magnet to make pictures of the inside of your body. A computer records changes in the magnetic field around your body. The computer then uses... read more 
(magnetic resonance imaging), to locate a blockage in your lymphatic system.
How do doctors treat lymphedema?
Lymphedema has no cure. The following may help lessen your swelling:
Elevating the swollen limb to help the fluid drain (for example, keeping your foot up on a stool)
Special massages to help drain fluid
Arm or leg movements suggested by your doctor to help move the fluid
Pressure bandages or stockings to wear on the swollen arm or leg
Rarely, surgery to remove the swollen tissues under the skin and to help lymph drain
It's important to avoid injuring an arm or leg with lymphedema. Also, if you have an arm with lymphedema, don't have your blood pressure taken on or blood drawn from that arm. That could make your lymphedema worse.
