Medical exams are an important part of our health regimen, and most aspects of it are pretty painless. However, there’s one part of the physical that remains as confusing as it is uncomfortable, no matter how old you get: The testicle exam.

When a doctor holds your testicles and asks you to cough, they are checking for a hernia — specifically the intestines pushing through into your testicles. A hernia occurs when an organ pushes through an opening in the muscle or tissue that holds it in place, and although they are most common in the abdomen, according to Healthline, they can also occur in the belly button and groin.

You are more likely to feel a hernia when you cough, as this increases the pressure in your abdomen and causes it to protrude, Young Men’s Health reported. In most cases, a hernia is not a serious health concern, though if a piece of intestine becomes trapped in the scrotum, it can cut off the blood supply to the intestine and cause serious problems if not quickly corrected. If a hernia is found, it can be easily remedied with surgery.

Although hernias are the main reason that a doctor may feel your testicles, they are not the only. The doctor may also be feeling for signs of testicular cancer, especially if you are aged 20 to 34, the most common age for men to develop this condition. Just like a breast exam for women, the doctor may feel the testicles looking for lumps or other abnormalities, Kids Health reported.

In addition, there are also lymph nodes in the groin, very close to the testicles. Swollen lymph nodes are usually a sign of infection, but in worse- case scenarios may occur when blood cancers such as lymphoma or leukemia spread to the lymph nodes. If you are sick, if could be possible the doctor is simply feeling your lymph nodes and you have mistaken it for a testicle exam.