Symptoms

• Swelling of part of your arm or leg or your entire arm or leg, including your fingers or toes
• A feeling of heaviness or tightness in your arm or leg
• Restricted range of motion in your arm or leg
• Aching or discomfort in your arm or leg
• Recurring infections in your affected limb
• Hardening and thickening of the skin on your arm or leg

The swelling caused by lymphedema ranges from mild, hardly noticeable changes in the size of your arm or leg to extreme swelling that can make it impossible to use the affected limb. If your lymphedema is caused by cancer treatment, you may not notice any swelling until months or years after treatment.  

Causes

Your lymphatic system is crucial to keeping your body healthy. It circulates protein-rich lymph fluid throughout your body, collecting bacteria, viruses and waste products. Your lymphatic system carries this fluid and harmful substances through your lymph vessels, which lead to lymph nodes. The wastes are then filtered out by lymphocytes — infection-fighting cells that live in your lymph nodes — and ultimately flushed from your body.

Lymphedema occurs when your lymph vessels are unable to adequately drain lymph fluid, usually from an arm or leg. Lymphedema can be either primary or secondary. This means it can occur on its own (primary lymphedema) or it can be caused by another disease or condition (secondary lymphedema). Secondary lymphedema is far more common than primary lymphedema.

Causes of secondary lymphedema
Any condition or procedure that damages your lymph nodes or lymph vessels can cause lymphedema. Causes include:

• Surgery. Lymphedema can develop if your lymph nodes and lymph vessels are removed or cut. For instance, surgery for breast cancer may include the removal of one or more lymph nodes in your armpit to look for evidence that cancer has spread. If your remaining lymph nodes and lymph vessels can't compensate for those that have been removed, lymphedema may result in your arm.
• Radiation treatment for cancer. Radiation can cause scarring and inflammation of your lymph nodes or lymph vessels, restricting flow of lymph fluid.
• Cancer. If cancer cells block lymphatic vessels, lymphedema may result. For instance, a tumor growing near a lymph node or lymph vessel could become large enough to block the flow of the lymph fluid.
• Infection. An infection of the lymph nodes can restrict the flow of lymph fluid and cause lymphedema. Parasites also can block lymph vessels. Infection-related lymphedema is most common in tropical and subtropical regions of the globe and is more likely to occur in developing countries.

Causes of primary lymphedema
Primary lymphedema is a rare, inherited condition caused by problems with the development of lymph vessels in your body. Primary lymphedema occurs most frequently in women. Specific causes of primary lymphedema include:

• Milroy's disease (congenital lymphedema). This is an inherited disorder that begins in infancy and causes your lymph nodes to form abnormally, leading to lymphedema.
• Meige's disease (lymphedema praecox). This hereditary disorder often causes lymphedema in childhood or around puberty, though it can occur in your 20s or early 30s. It causes your lymph vessels to form without the valves that keep lymph fluid from flowing backward, making it difficult for your body to properly drain the lymph fluid from your limbs.
• Late-onset lymphedema (lymphedema tarda). This occurs rarely and usually begins after age 35.

Tests and diagnosis

Your doctor may try to rule out other causes of swelling when diagnosing lymphedema. Swelling can have many causes, including a blood clot or an infection that doesn't involve your lymph nodes.

If you're at risk of lymphedema — for instance, if you've recently had cancer surgery involving your lymph nodes — your doctor may diagnose lymphedema based on your signs and symptoms.

If the cause of your lymphedema isn't as obvious, your doctor may order imaging tests to determine what's causing your signs and symptoms. To get a look at your lymphatic system, your doctor may use an imaging technique, such as:

• Magnetic resonance imaging (MRI). Using a magnetic field and radio waves, an MRI produces 3-D, high-resolution images. An MRI gives your doctor a better look at the tissues in your arm or leg. He or she might be able to use an MRI to see characteristics of lymphedema.
• Computerized tomography (CT). A CT scan — also called computerized tomography, or just CT — is an X-ray technique that produces detailed, cross-sectional images of your body's structures. CT scans can reveal areas of the lymphatic system that may be blocked.
• Doppler ultrasound. This variation of the conventional ultrasound looks at blood flow and pressure by bouncing high-frequency sound waves (ultrasound) off red blood cells. Ultrasound can be helpful in finding obstructions.
• Radionuclide imaging of your lymphatic system (lymphoscintigraphy). During this test you're injected with a radioactive dye and then scanned by a machine. The resulting images show the dye moving through your lymph vessels, highlighting areas where the lymph fluid is blocked.

Treatments and drugs

There's no cure for lymphedema. Treatment focuses on reducing the swelling and controlling the pain. Lymphedema treatments include:

• Exercises. Light exercises that require you to move your affected arm or leg may encourage movement of the lymph fluid out of your limb. These exercises shouldn't be strenuous or make you tired. Instead, they should focus on gentle contraction of the muscles in your arm or leg. Your doctor or a physical therapist can teach you exercises that may help.
• Wrapping your arm or leg. Bandages wrapped around your entire limb encourage lymph fluid to flow back out of your affected limb and toward the trunk of your body. When bandaging your arm or leg, start by making the bandage tightest around your fingers and toes. Wrap the bandage more loosely as you move up your arm or leg. A lymphedema therapist can show you how to wrap your limb.
• Massage. A special massage technique called manual lymph drainage may encourage the flow of lymph fluid out of your arm or leg. Manual lymph drainage involves special hand strokes on your affected limb to gently move lymph fluid to healthy lymph nodes, where it can drain. Massage isn't for everyone. Avoid massage if you have a skin infection, active cancer, blood clots or congestive heart failure. Also avoid massage on areas of your body that have received radiation therapy.
• Pneumatic compression. If you receive pneumatic compression, you'll wear a sleeve over your affected arm or leg. The sleeve is connected to a pump that intermittently inflates the sleeve, putting pressure on your limb. The inflated sleeve gently moves lymph fluid away from your fingers or toes, reducing the swelling in your arm or leg.
• Compression garments. Compression garments include long sleeves or stockings made to compress your arm or leg to encourage the flow of the lymph fluid out of your affected limb. Once you've reduced swelling in your arm or leg through other measures, your doctor may suggest you wear compression garments to prevent your limb from swelling in the future. Obtain a correct fit for your compression garment by getting professional help — ask your doctor where you can buy compression garments in your community. Some people will require custom-made compression garments.

When several of these treatments are combined, this therapy may be referred to as complete decongestive therapy (CDT). Generally, CDT isn't recommended for people who have high blood pressure, diabetes, paralysis, heart failure, blood clots or acute infections.

In cases of severe lymphedema, your doctor may consider surgery to remove excess tissue in your arm or leg. While this reduces severe swelling, surgery can't cure lymphedema.

Prevention

If you're at risk of developing secondary lymphedema, you can take measures to help prevent it. If you've had or are going to have cancer surgery, ask your doctor whether your particular procedure will involve your lymph nodes or lymph vessels. Ask if your radiation treatment will be aimed at any of your lymph nodes, so you'll be aware of the possible risks.

To reduce your risk of lymphedema, try to:

• Protect your arm or leg. Avoid any injury to your affected limb. Cuts, scrapes and burns can all invite infection, which can result in lymphedema. Protect yourself from sharp objects. For example, shave with an electric razor, wear gloves when you garden or cook, and use a thimble when you sew. If possible, avoid medical procedures, such as blood draws and vaccinations, in your affected limb.
• Rest your arm or leg while recovering. After cancer treatment, avoid heavy activity with that limb. Early exercise and stretching are encouraged, but avoid strenuous activity until you've recovered from surgery or radiation.
• Avoid heat on your arm or leg. Don't apply heat, such as with a heating pad, to your affected limb.
• Elevate your arm or leg. When you get a chance, elevate your affected limb above the level of your heart, if possible.
• Avoid tight clothing. Avoid anything that could constrict your arm or leg, such as tightfitting clothing and, in the case of your arm, blood pressure readings. Ask that your blood pressure be taken in your other arm.
• Keep your arm or leg clean. Make skin care and nail care high priorities. Inspect the skin on your arm or leg every day, keeping watch for changes or breaks in your skin that could lead to infection. Don't go barefoot outdoors.