Hello,
Testicle pain is discomfort in one or both testicles. The pain sometimes radiates to the lower abdomen. Testicular pain can be due to injury, infection (Epididymitis or Orchitis) or inflammation, testicular torsion -- most common in young men between 10 and 20 years old, excessive bicycle riding, hernia or kidney or ureteric stones.
As there is no swelling or inflammation or redness of the scrotal sacs, so the chances of epidiymitis or orchitis are rare. pain due to torsion comes suddenly and is severe and acute in nature. Moreover it is often accompanied by nausea and vomiting. Pain in varicocele subsides on lying down.
The final diagnosis can only be made after a thorough physical examination including examination of the abdomen, scrotum, testicles and rectum.
Lab investigations like complete blood examination, urine examination, ultrasound lower abdomen and sometimes a urethral swab will help in diagnosis. Treatment will be started thereafter.
I hope it helps. Take care and regards.