Swollen lymph nodes, also known as lymphadenopathy, are usually caused by an immune response to an infection from bacteria or viruses. The lymph nodes contain white blood cells that help fight off infections, and when the body is fighting an infection, the lymph nodes can swell as a result of the increased production of immune cells.

Infections that can cause swollen lymph nodes include:

• Abscessed or impacted tooth
• Ear infection
• Colds, flu, and other infections
• Mononucleosis
• Sexually transmitted illnesses
• Tonsillitis
• Tuberculosis
• Skin infections
• Certain types of cancer.

In rare cases, swollen lymph nodes can be caused by cancer. Other less common causes of swollen lymph nodes include injury, autoimmune disorders, and certain medications.

Its important to note that swollen lymph nodes are usually a sign that the body is fighting off an infection or illness, and they often return to normal size once the underlying cause has been resolved. However, if swollen lymph nodes appear suddenly, are painful, or persist without an apparent reason, its advisable to seek medical attention for further evaluation and possible tests to identify the cause.