How do i tell if i have a cyst?

Depends on where: A cyst is a pocket of fluid and can occur in many different types of tissue. If it's in or close to the skin, you can feel it. If it's deeper down you may never know, and that's ok because most never cause problems. If it does get too big and pushes on something that causes pain, then they can often be found with ultrasound, CT or MRI studies in the liver, kidneys, pancreas... almost anywhere.