Lymph

Lymph (pronounced “limf”) is a colorless, watery fluid that flows through your lymphatic system. Lymph helps your lymphatic system support your overall health. It provides nutrients to cells and tissues. It also sweeps up harmful intruders, like viruses, bacteria and cancer cells, so your body can destroy them. And that’s just some of what it does.

Lymph is an essential body fluid. It’s as important to your lymphatic system as blood is to your circulatory system.

What does it do?

To understand what lymph does, it may help to know where it comes from. That story starts with your circulatory system, which partners with your lymphatic system. Your circulatory system is a network of arteries, veins and capillaries that carry blood throughout your body. Blood contains fluid called plasma.

As blood flows through your capillaries, some plasma seeps through tiny holes in the capillary walls. This plasma — now called lymph — moves into your tissues and the spaces around your cells. It delivers oxygen, proteins and other nutrients to cells and tissue.

At the same time, lymph sweeps up debris, like damaged and cancerous cells, bacteria and viruses. Lymph also picks up extra fluid from your tissues and cells that your blood capillaries can’t absorb.

Loaded down with extra fluid and harmful organisms, lymph moves into lymphatic capillaries that transport lymph to larger lymphatic vessels. As it travels, lymph eventually flows through bean-shaped tissue called lymph nodes. Lymph nodes trap harmful organisms and cancer cells, so they can be destroyed by white blood cells (lymphocytes).

The filtered lymph exits your lymph nodes and eventually returns to your bloodstream. The newly added fluid helps maintain a healthy blood pressure.

Where is lymph located?

Lymph is anywhere you have lymphatic capillaries. And there are lymphatic capillaries in the tissues of nearly every organ in your body. Your liver and digestive system produce 80% of lymph in your body. That lymph is called chyle.

What does lymph look like?

It’s typically clear or colorless, but it can also be yellow. Chyle contains a mixture of white blood cells and fat that makes it look milky.

What is lymph made of?

Lymph fluid is mostly made of plasma that oozes out from your blood capillaries. Depending on where it’s located in your lymphatic system, lymph may also contain white blood cells and plasma cell proteins. It may carry germs, cancerous cells and cell debris.

Chyle contains these parts, plus fats and cholesterol. 

What are common conditions and disorders that affect lymph?

Lymph needs to keep moving to carry out its jobs. If there’s a blockage in your lymph nodes, fluid can build up in nearby soft tissue instead of flowing freely. This leads to swelling, the most common sign of lymph fluid issues.

Conditions that can cause this include:

• Lymphedema happens when lymph can’t flow into lymphatic capillaries. It usually shows up as swelling in your arms and legs. This most often happens after you’ve had radiation or surgery to remove lymph nodes.
• Elephantiasis blocks your lymphatic system so lymph can’t flow through the system. It can lead to swelling in your arms, legs or genitals.
• Cancerous tumors that block lymphatic ducts or lymph nodes may affect how lymph moves around your body.

How can I take care of my lymph fluid?

Taking care of your lymphatic system is the best way to take care of your lymph fluid. To keep your lymphatic system strong and healthy, you should:

• Avoid exposure to toxic chemicals, like those in pesticides or cleaning products. These chemicals can build up in your system and make it harder for your body to filter waste.
• Drink plenty of water to stay hydrated so lymph can easily move throughout your body.
• Maintain a healthy routine that includes regular exercise and eating nutritious foods.
• Stick to eating foods low in salt. Reducing your salt intake can lessen how much fluid you retain in your body. This can decrease the volume and pressure in your lymph vessels.

Is lymph fluid the same as a lymphocyte?

No, lymph fluid isn’t the same as lymphocytes. But there may be lymphocytes in your lymph fluid. Lymphocytes are white blood cells that fight infection. They’re found in lymph and other lymphatic tissues that make up your lymphatic system.

Can lymph be cancer?

No, but lymph can contain cancer cells. One of lymph’s jobs is to carry cancer cells to your lymph nodes. Your lymph nodes filter out the cancer cells, taking them out of circulation. This is why healthcare providers often check lymph nodes for cancer cells during diagnosis.

Lymphoma is cancer in your lymph system. It happens when normal lymphocytes (white blood cells) transform into cancer cells.