How do you know if you have swollen lymph nodes in the groin vs an inguinal hernia? what differentiates the two?

Few differences: Inguinal hernia is a protrusion of the intestines either directly through the muscular layer or through a canal. Lymph nodes are usually movable from side to side, do not increase in size with coughing or increased abdominal pressure.

Cough impulse: Lymph nodes often feel like round mobile lumps which may be tender. A hernia can usually be seen as a swelling and you can push it back inside lying down. The swelling will have a cough impulse which means you will feel it expanding if you put your hand on it and cough.

Physical Exam: Physical exam by a physician could usually tell the difference. Imaging studies such as a ct scan could also assist with diagnosis. In general hernias go in and out unless it is trapped or incarcerated. Swollen lymph nodes are usually multiple and don't move except for small movements.

Monitoring Centers: Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells/digested food. Lymph nodes "taste" the lymph everywhere for bad stuff like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.

See a doctor: Have a physical exam. Very difficult for you to tell, but in general a lymph node may be tender & it would be fixed & firm and not go away when laying down or resting. Hernia often softer, located in a different position than a lymph node & usually goes away when you lay down.