Acute bacterial prostatitis refers to inflammation of the prostate gland that is caused by a bacterial infection, such as a sexually-transmitted infection or a urinary tract infection. Bacteria can travel up the urethra (the tube from which men urinate and ejaculate semen) to the prostate.

Doctors use several methods to diagnose acute bacterial prostatitis:

• Physical exam. The doctor checks for tenderness or swelling in the scrotum and the lymph nodes of the groin and notes any unusual discharge from the urethra.

• Digital rectal exam. By inserting a gloved finger into the patient’s rectum, the doctor examines the prostate directly, feeling for any swelling or tenderness.

• Transrectal ultrasound. An ultrasound uses sound waves to create a picture of the prostate that a doctor can see, and analyze, on a computer screen.

• Specimen tests (urine, blood, semen). Sometimes, doctors take samples of urine, blood, or semen to analyze further in a lab. These tests can provide clues about the type of infection involved.

Many of these procedures can be done in a doctor’s office.