Lymph nodes are located throughout your body in areas such as your armpits, under your jaw, and on the sides of your neck.

These kidney-bean-shaped masses of tissue protect your body from infection and filter a clear fluid, called lymph, that circulates through your lymphatic system. Lymph contains a large number of white blood cells that protect your body against bacteria and viruses.

By trapping viruses and bacteria, lymph nodes prevent them from spreading to other areas of your body and causing illness. When your lymph nodes are swollen, it is an indicator they’re fighting an infection or illness.

If you have swollen lymph nodes, you shouldn’t immediately expect cancer. However, you should visit your doctor if:

  • your lymph nodes continue enlarging
  • swelling is present for more than two weeks
  • they feel hard and you can’t move them when you press them

Though rare, swollen lymph nodes can be a sign of cancer. Two primary cancers associated with swollen lymph nodes are lymphoma and leukemia.

Lymphoma

The two common types of lymphoma are Hodgkin’s lymphoma and non-Hodgkin’s lymphoma. Along with swollen lymph nodes, lymphoma has symptoms such as:

Risk factors include:

  • Sex. Males are more likely to develop lymphoma.
  • Age. Some types of lymphoma are common in those over age 55, while others are most often experienced by young adults.
  • Immune system. If you already have a condition associated with your immune system, or you take medication that impacts your immune system, you may be at a higher risk for lymphoma.

Leukemia

Leukemia causes an increase of abnormal white blood cells, which then crowd out the healthy ones that fight infection. One symptom of leukemia is swollen lymph nodes. Clusters of abnormal white blood cells collect in your lymph nodes, resulting in enlargement.

Other symptoms of leukemia that accompany swollen lymph nodes include:

  • anemia
  • easily bleeding or bruising
  • discomfort under your lower left ribs

You may have a higher risk of leukemia if you:

  • smoke cigarettes
  • have history of leukemia in your family
  • have had chemotherapy or radiation from previous cancer treatment

Swollen lymph nodes are often not a sign of cancer. Instead, you may be experiencing:

Your doctor can provide a proper diagnosis and treatment plan, as treatment will depend on the specific cause. Many cases of swollen lymph nodes fade on their own without treatment.

Swollen or enlarged lymph nodes aren’t always a sign of cancer, but you should seek medical attention if symptoms persist or appear unusual.

Your doctor may examine your medical history, perform a lymph node biopsy, or conduct imaging studies such as a chest X-ray or CT scan to further determine the underlying causes.