Lymph nodes in the human body are similar to sensors in your car. However, the car's sensors just go on to indicate that some part of your car is malfunctioning, but your lymph nodes give much more information. The exact position( 7 levels in the neck) can accurately point out to your clinician where the problem lies but the type and texture of swelling can also tell him if it is an acute inflammation (as in your case) or it is tuberculous or a lymphoma or a cancer!( Here, PAINFUL swelling is actually good news- can be treated easily with antibiotics and anti-inflammatory drugs