Lymphedema: The Basics

Author: OncoLink Team
Content Contributor: Andrea Branas, MSE, MPT, CLT and Joy Cohn, PT, DPT, CLT
Last Reviewed: July 11, 2022

What is lymphedema?

Lymphedema is swelling that builds up over time and doesn’t go away quickly (chronic swelling). It happens when lymph fluid is not moving well through a part of the body and protein-rich fluid collects in the tissues.

The lymph system is made up of lymph nodes and vessels. The lymph vessels are next to the blood vessels. The lymph system helps manage fluid volume and fight disease. Lymph nodes and vessels drain extra fluid from the body and return it to the blood near the heart. Lymph nodes filter viruses, dying cells, foreign matter, and bacteria to fight infection. The lymph system also recycles proteins through the body. Lymphedema happens slowly unless there is an injury or infection to the area of the body where your lymph nodes and vessels are not working.

Types of Lymphedema

Some people are born with (inherit) a poorly working lymph system. This is called primary lymphedema. Lymphedema can also happen when lymph nodes or vessels are damaged from trauma, or surgery or radiation for cancer treatment. Damaged leg veins or a history of blood clots can cause a backup of blood and fluid in the small vessels of the body. These are all causes of secondary lymphedema.

Lymphedema Risk

Things that increase your risk of lymphedema are:

  • Lymph node removal.
  • Receiving radiation therapy.
  • Being overweight.
  • Having active cancer.
  • Infection/injury to the body part at risk for lymphedema.

Not all swelling in the body is lymphedema. Talk to your provider if you notice any new or worsening swelling. For more information on lymphedema risk, see the article on risk reduction for lymphedema.

What are some signs of lymphedema development?

Signs of lymphedema are:

  • Swelling that often begins at the far end of your limb (hands and feet) and then moves up the arm or leg. The swelling does not get better over time and may slowly get worse.
  • Skin can be pitting (when a finger is pressed into the area the indentation remains).
  • Swelling may or may not go down with elevation (keeping the affected body part above the level of your heart).
  • Hardening of the tissues in the affected area.

What skin changes are seen with lymphedema?

Skin changes can happen with lymphedema, such as:

  • Local infections, often called "cellulitis," may cause the limb to become red, hot, painful, and swollen. This infection can spread quickly, so early diagnosis can keep the infection and swelling under control.
  • Lymphedema can be pitting or non-pitting edema (swelling). Pitting edema is when a mark is left in the skin after applying pressure from a finger, hand, or object. This is often seen with a recent collection of fluid and protein.
  • Hyperkeratosis and papillomas may also be seen in someone with lymphedema. Hyperkeratosis is an overgrowth of the skin like a very thick callus. Papillomas are raised wart-like growths that can show up on the skin of people with lymphedema.

How is lymphedema diagnosed?

Your medical history is the key to the diagnosis of lymphedema. Your provider will look at your history from cancer diagnosis to treatment along with any past surgeries or medical history. These factors will be used to help determine your risk for lymphedema

Providers will use clinical and diagnostic tools to determine a diagnosis of lymphedema. Some of these tests are also used to rule out other causes of swelling:

  1. Look and feel of the skin.
  2. Stemmer sign is when the folds of skin on the top of the toes and fingers becomes hard or loses flexibility. The skin cannot be pinched and lifted or is difficult to lift. A negative Stemmer sign does NOT mean that there is no lymphedema.
  3. Swelling in the limb. Most providers will measure around your arm or leg at standard spots along both limbs. For example, patients with arm lymphedema may be measured at the knuckles, wrist, elbow, and upper arm. They will compare both sides to see if one is larger than the other.
  4. Diagnostic tests like ultrasound, lymphoscintigraphy, CT, and MRI may be used. These tests are also used to rule out local infection (phlebitis) or blood clot (DVT) as the cause of the swelling. X-rays, bone scans, or blood work may be done to rule out a recurrence of cancer.

When these tests are negative for other causes, the patient history and physical examination are usually enough to make the diagnosis of lymphedema.

Specific tests of the lymphatic system are used when the diagnosis is unclear or if more information about the lymphatic system is needed. Diagnostic tests may include lymphoscintigraphy, ultrasound, CT, or MRI.

  • Lymphoscintigraphy is a nuclear medicine test where a fluid is injected into the lymphatic system. This fluid is then followed as it is carried through the body. It shows what the lymphatic system looks like and how it’s working.
  • Ultrasound can look at enlarged lymph nodes.
  • Computerized tomography (CT) scans are useful to look for soft tissue growths in the lymph nodes or to find metastatic disease.

What are the stages of lymphedema?

There are 4 stages of lymphedema based on how long the fluid has been in the body part and what type of changes are seen because of the fluid.

In the pre-stage (latency stage), the body is starting to have trouble moving the lymphatic fluid in the damaged area. You may start to have symptoms like clothing feeling too tight or pain in the area. The lymphedema is treatable and reversible at this stage.

In Stage I, there is very little swelling. The swelling that does exist may come and go. At this stage, the lymphedema is said to be reversible. There may be times when there is no swelling.

In Stage II, there is more swelling, because the fluid is in the tissues. The skin may feel tighter and may be shiny. The tissue may also feel thick and firm to the touch. The tissue may form pits when pressed. These changes are caused by scar tissue, or fibrosis, beginning to form. The fluid can be moved out of the tissue, but it won't happen without help from the outside.

Stage III lymphedema is a severe and prolonged collection of edema or swelling in the body part. The skin can become hardened with a leathery feel. The color of the skin can become darker with a brownish tint. There may also be papillomas of the skin, which are small bumps that form on the skin and may leak fluid. This stage is called lymphostatic elephantiasis. It is not possible for the body to clear the fluid on its own. Even with intense therapy, this fluid is hard to remove. Tissue changes and softening may be seen with treatment. Learn more about lymphedema treatment.

If you notice any new or worsening swelling, it is important to talk to your provider. Diagnosing and treating lymphedema early on leads to better outcomes.

Resources for More Information

National Lymphedema Network

Australasian Lymphology Association

Lymphatic Education & Research Network

Next Article: Understanding and Decreasing Lymphedema Risk »


American Cancer Society. What is Lymphedema.


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