Your body needs some sodium to function properly because it: 1  Helps maintain the right balance of fluids in your body. 2  Helps transmit nerve impulses. 3  Influences the contraction and relaxation of muscles.
Some of the conditions that can cause a testicle lump, swelling, and/or pain include: 1  Torsion of the testicle. 2  Injury. 3  Infection. Hydrocele. 4  Varicocele. Epididymal cyst/spermatocele.  Inguinal 1  hernia. Kidney  stones.
Other causes of swelling and/or pain in the testes can include: 1  Hydrocele, a collection of fluid in the scrotum.  Epididymal cyst, a fluid-filled swelling of the epididymis (the structure behind the testicle where sperm mature) which may also cause fever and discharge from the penis.