The lymphatic system helps coordinate the immune system's function to protect the body from foreign substances and includes an extensive network of lymph vessels and lymph nodes. Here's how the lymphatic system works:

Excess fluid is collected from the space between tissues in the body and moves through the lymph vessels. The fluid (now called lymph) isn't pumped through the body like blood, but instead is "pushed" through the lymph system as the vessels are compressed by surrounding muscles.

Filters called lymph nodes remove certain harmful substances from the lymph fluid, such as bacteria and debris. The fluid from most tissues or organs is filtered through one or more lymph nodes before draining into the bloodstream.

Lymphedema is an abnormal buildup of fluid that causes swelling, most often in the arms or legs. The condition develops when lymph vessels or lymph nodes are missing, impaired, damaged, or removed.

There are two types of lymphedema: primary and secondary. Primary lymphedema is rare and is caused by the absence of certain lymph vessels at birth, or abnormalities in the lymphatic vessels. Secondary lymphedema occurs as a result of a blockage or interruption that alters the flow of lymph through the lymphatic system and can develop from an infection, malignancy, surgery, scar tissue formation, trauma, deep vein thrombosis (blood clot in a vein), radiation, or other cancer treatment.

People who have had any of the following procedures may be at risk for developing lymphedema:

• Simple mastectomy in combination with axillary (arm pit) lymph node removal.
• Lumpectomy in combination with axillary lymph node removal.
• Modified radical mastectomy in combination with axillary lymph node removal.
• Combined cancer surgery and radiation therapy to a lymph node region (such as the neck, armpit, groin, pelvis or abdomen).
• Radiation therapy to a lymph node region.

Lymphedema can occur within a few days, months, or years after surgery. A small amount of swelling is normal for the first four to six weeks after surgery.

Lymphedema develops after breast surgery because there is an alteration in the pathway that drains the fluids involved in the immune system. It can occur at any time after the surgery. If untreated, it can become worse.

Following surgery, a physician will examine you and take arm measurements. Sometimes, there may be redness or pain in the arm, which may be a sign of inflammation. Depending on your symptoms, your physician will then consider the best treatment options for you.

If you suspect any of the symptoms listed below, call your healthcare provider right away. Prompt treatment can help get the condition under control.

• Swelling in the arms, hands, fingers, shoulders, chest, or legs. The swelling may occur for the first time after a traumatic event (such as bruises, cuts, sunburn, and sports injuries), after an infection in the part of the body that was treated for cancer, or after an extended (more than three hours) airplane trip (due to the sudden change in cabin pressure).
• A "full" or heavy sensation in the arms or legs.
• Skin tightness.
• Decreased flexibility in the hand, wrist, or ankle.
• Difficulty fitting into clothing in one specific area.
• Tight-fitting bracelet, watch, or ring that wasn't tight before.

Lymphedema is diagnosed after a careful evaluation of your medical history, including past surgeries and treatments, an evaluation of current medications and symptoms, and a complete physical examination. Sometimes, additional tests may be needed.

To help decrease the risk of further swelling, continue following the recommendations for preventing lymphedema listed above. In addition:

• Avoid extreme temperature changes. Do not use hot tubs, whirlpools, saunas or steam baths. Use warm, rather than very hot, water when bathing or washing dishes. Always wear sun protection (at least SPF 15) when going outdoors.
• When traveling by air, ask your healthcare provider if you should wear a compression sleeve on your affected arm or a stocking on your affected leg. For long flights, additional bandages may be needed. Talk to your healthcare provider before traveling.
• When sitting or sleeping, elevate your affected arm or leg on pillows. Avoid prolonged lying on your affected side.
• Your physician may refer you to an occupational therapist who specializes in managing lymphedema. The therapist will assess your condition and develop an individual treatment plan to manage your lymphedema.
• Therapy may include specific exercises or a complete exercise program, limitation of certain activities that are vigorous or repetitive, and recommendations for a compression sleeve, bandages, manual lymph drainage and possibly a pump.
• Continue to see your health-care provider for frequent follow-up visits, as recommended.

Lymphedema cannot be cured. However, with proper care and treatment, the affected limb can be restored to a normal size and shape. In addition, lymphedema can be treated and controlled so that it does not progress further.

If left untreated, lymphedema can lead to increased swelling and a hardening of the tissue, resulting in decreased function and mobility in the affected limb. It can also lead to chronic infections and other illnesses.

It is important to receive treatment promptly if you recognize symptoms of lymphedema.