Many uncircumcised guys don't have any problems with foreskin. However, some problems associated with foreskin in uncircumcised guys include:
If you have any of these problems, see your doctor.
Inflammation or infection of the penis head
The foreskin can't be pulled back behind the head of the penis because it is too tight
The foreskin, after being pulled back, becomes trapped behind the head of the penis; this is a medical emergency because it can cause permanent damage to the penis. You should see your doctor immediately.
A rare condition where scar tissue forms at the tip of the penis, tightening the foreskin around the penis head; this makes it difficult for the foreskin to be pulled back.