Testicular pain can occur in or around one or both testicles and can be due to a number of causes. The testicles are very sensitive organs, and even a minor injury can cause testicle pain or discomfort. Testicle pain may arise from the testicle itself or from the structure behind the testicle (epididymis), problems that start in the groin or lower abdomen or trauma. Seek medical attention as soon as possible.