Reasons for Swollen Lymph Nodes: When Should You See the Doctor?
- The CDC reports that 11% of people who get a COVID-19 vaccine are experiencing swollen lymph nodes after one dose, and 16% do so after the second dose.
- Swelling after a COVID vaccine has gone away in 1-2 weeks in almost all cases
- Swelling from vaccination is the body’s response to the vaccine. This is very different from the longer term swelling that can be associated with cancer.
- Speak to your doctor if you develop swollen lymph nodes that are painful or persist for more than one to two weeks.
These areas that may become swollen after the COVID vaccines are called lymph nodes and play an extremely important role in our body’s immune system. Normally, we do not notice our lymph nodes as most of the time they are small, not swollen, and do not cause us any pain. But certain infections and conditions including cancer can cause these nodes to enlarge, swell, and become painful.
Read MoreWhat is a Lymph Node, Where Are They Located, and What Do They Do?
Lymph nodes, sometimes referred to as lymph glands, are a vital aspect of the body’s immune system. These glands filter the body’s lymphatic fluid and contain many lymphocytes or white blood cells that are used to fight off infections or attack cancerous cells. Another way to think about lymph nodes is a specialized filtration system designed to protect our bodies against invaders such as germs and viruses. Lymph nodes are located throughout the body including the neck, under the arm (armpit), throughout the abdomen, and into the groin. Lymph nodes are connected by lymph vessels, which function as a highway and allow the lymph fluid to move from one node to another. These vessels also allow the disease-fighting white blood cells to effectively ward off invaders. Usually, when our bodies are not fighting an infection or a cancer, we do not notice our lymph nodes. They are like a silent security system continuously monitoring our bodies for foreign invaders and responding quickly when an intruder is noticed. However, when white blood cells and lymph nodes became activated they can quickly enlarge and even become painful. This is when you may notice these areas.What Can Cause Lymph Nodes to Swell?
Many things can cause a lymph node to be swollen, including infection and cancer.
Many things can cause our lymph nodes to be swollen. The most common reason is infection. This is why your doctor may feel the outside of your neck when you are being evaluated for a sickness. He or she is feeling for any signs of swollen lymph nodes, which can be a clue that your body is fighting an infection. Another cause of swollen lymph nodes can be due to an inflammatory or immune response. This is the case with the COVID-19 vaccine.
Why Does The Body Swell After a COVID-19 Vaccine?
Following vaccine administration, the body starts to create memory white blood cells to be able to recognize and fight the virus if it becomes exposed at a future time. Because lymph nodes contain large amounts of white blood cells, some people will notice their lymph nodes swell following a vaccine as these cells are reacting to the vaccine. Typically, swollen lymph nodes should resolve following an infection or another stimulus such as a vaccine within a relatively short time period. If you notice swollen lymph nodes that last longer than one to two weeks you should contact your doctor.
Related: I'm In Active Cancer Treatment Can I Get the COVID-19 Vaccine?
What About Swollen Lymph Nodes and Cancer?
Another reason your lymph nodes can swell is because of cancer. Some cancers, such as lymphoma, involve the lymph nodes and cause them to grow and swell. Other cancers can spread or metastasize to lymph nodes which can also cause them to become enlarged. Sometimes, the nodes can enlarge in a person with cancer because the body is fighting the cancer and this does not mean that the cancer has spread into their lymph nodes. One common cancer that can often cause swelling in the armpit is breast cancer. These are the same lymph nodes that have been reported to swell after the COVID-19 vaccine. If you notice swollen nodes in this area that do not go away in one to two weeks you should discuss this with your doctor.
Related: Non-Hodgkin Lymphoma: Learning More About Your Tumor
When Should You Speak to Your Doctor?
You should call your doctor whenever you notice an enlarged and painful lymph node.
You should call your doctor whenever you notice an enlarged or painful lymph node. Other symptoms such as night sweats, weight loss, and fatigue should also prompt you to visit your doctor. While it may be normal for your lymph nodes to swell up following an infection or vaccine, it is not normal for them to remain swollen. Speak to your doctor if your nodes continue to be swollen for more than a week. You should also make an appointment if you have painful lymph nodes, as this may be a sign of cancer or another condition that requires treatment.
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