A patient presents with swollen lymph nodes. This finding may indicate which condition?

A patient presents with swollen lymph nodes. This finding may indicate which condition?

• A. Pleural effusion
• B. Blood clots
• C. Infection
• D. Emboli

Answer: (C)

Swollen lymph nodes occur when the immune system is activated by pathogens. Lymph nodes are the checkpoints where immune cells meet foreign invaders; during infection, these cells multiply and fluid and inflammatory cells accumulate in the node, making it enlarge and sometimes tender. This is why an infection is the most likely explanation for enlarged lymph nodes. Pleural effusion involves fluid around the lungs, not lymph node activity. Blood clots cause swelling by venous blockage, and emboli cause tissue blockage, neither of which typically produce lymph node enlargement. If a node remains enlarged, hard, or fixed, or there are systemic symptoms, it should be evaluated further.

Swollen lymph nodes occur when the immune system is activated by pathogens. Lymph nodes are the checkpoints where immune cells meet foreign invaders; during infection, these cells multiply and fluid and inflammatory cells accumulate in the node, making it enlarge and sometimes tender. This is why an infection is the most likely explanation for enlarged lymph nodes. Pleural effusion involves fluid around the lungs, not lymph node activity. Blood clots cause swelling by venous blockage, and emboli cause tissue blockage, neither of which typically produce lymph node enlargement. If a node remains enlarged, hard, or fixed, or there are systemic symptoms, it should be evaluated further.