Diagnosis

Your doctor is likely to start with your medical history and a physical exam to check for enlarged lymph nodes in your groin and an enlarged testicle on the affected side. Your doctor might also do a rectal examination to check for prostate enlargement or tenderness.

Your doctor might recommend:

• STI screen. If you have discharge from your urethra, a narrow swab is inserted into the end of your penis to obtain a sample of the discharge. The sample is checked in the laboratory for gonorrhea and chlamydia. Some STI screens are done with a urine test.
• Urine test. A sample of your urine is analyzed to see if anything's abnormal.
• Ultrasound. This imaging test is the one most commonly used to assess testicular pain. Ultrasound with color Doppler can determine if the blood flow to your testicles is lower than normal — indicating torsion — or higher than normal, which helps confirm the diagnosis of orchitis.