How do i know if i have a hydrocele?

Ultrasound: You will need to see your doctor to be examined, and then have an ultrasound to verify it. If you have a change in your testicle, a lump or pain, swelling or redness, definitely you should see your doctor.

Scrotal swelling: Usually painless confirmed by scrotal ultrasound. Should transilluminate, in which case it will permit light to shine through because hydrocele fluid is clear. This is not 100% reliable because secondary hydrocele can be present with a testicular tumor. Also can be present with testis torsion or epididymitis, but these conditions are associated with pain.

See your MD: A hydrocele is typically a painless scrotal enlargement surrounding the testis and often making it difficult to feel the testis itself. It is diagnosed with certainty by ultrasound. Transillumination (by seeing it "glow" when a light is pushed against the skin) is helpful but cannot rule out other concerns.