Why do people have a swollen lymph node when they are sick?

When you are sick, your body produces more white blood cells to fight the infection. These white blood cells can collect in the lymph nodes, causing them to swell. Lymph nodes are small, bean-shaped organs that are located throughout the body. They help to filter out bacteria, viruses, and other harmful substances from the blood.

Swollen lymph nodes are often a sign of an infection, but they can also be caused by other conditions, such as cancer or autoimmune disorders. If you have swollen lymph nodes that do not go away after a few weeks, it is important to see a doctor to rule out any underlying medical conditions.

Here are some of the most common causes of swollen lymph nodes:

* Infection: Swollen lymph nodes are often a sign of an infection, such as a cold, flu, or strep throat.

* Cancer: Swollen lymph nodes can also be a sign of cancer, such as leukemia, lymphoma, or breast cancer.

* Autoimmune disorders: Swollen lymph nodes can be a symptom of autoimmune disorders, such as lupus or rheumatoid arthritis.

* Other conditions: Swollen lymph nodes can also be caused by other conditions, such as allergies, HIV, or tuberculosis.

If you have swollen lymph nodes, it is important to see a doctor if:

* The swelling does not go away after a few weeks

* The swelling is painful

* The swelling is accompanied by other symptoms, such as fever, weight loss, or night sweats

Your doctor will perform a physical exam and may order tests, such as a blood test or biopsy, to determine the cause of the swollen lymph nodes.