In some cases, men with benign prostatic hyperplasia (BPH) notice symptoms and schedule an appointment with a physician for an examination. In other cases, the problem may be discovered by a physician during a routine physical examination.

A physician will review the patient’s medical history and perform a physical in making the diagnosis. The physician will ask the patient about his symptoms. 

The physician will want to rule out other medical conditions, such as  sexually transmitted diseases, prostatitis or diabetes, that could cause similar symptoms. Most patients with symptoms of acute urinary retention (the inability to urinate) have BPH. However, some patients may have other serious conditions, such as prostate cancer, bladder stones, bladder infection or interstitial cystitis.

If BPH or another urological condition is suspected, the patient likely will be referred to a urologist, a physician who specializes in problems associated with the urinary tract in males and females and in the male reproductive system.

Several tests can be used to help make an accurate diagnosis. These include:

• Digital rectal examination (DRE). The physician inserts a gloved, lubricated finger in the patient’s rectum and manually feels the prostate to determine its size and condition. A patient’s regular physical examination often includes a DRE.
  
  
• Questionnaire. The American Urological Association has developed a questionnaire about symptoms associated with an enlarged prostate. This pain assessment form can help determine the severity of the condition and monitor the condition over time.
  
  
• Prostate specific antigen (PSA) test. This blood test detects PSA, a protein produced by prostate cells. Prostate cancer and prostatitis are among the conditions that may elevate PSA.
  
  
• Postvoid residual volume test. A catheter (flexible tube used to drain urine from the bladder) can be inserted into the urethra or, more often, noninvasive ultrasound is used to see how well the patient is able to empty his bladder during urination.
  
  
• Other imaging tests. During a rectal ultrasound, a probe is inserted into the rectum to assess structural characteristics of the prostate by reflecting sound waves off the gland. This forms an image of the prostate on a display screen. An x-ray of the urinary tract called intravenous pyelography (IVP) also may be used.
  
  
• Urine flow study. The patient urinates into a device that detects how quickly urine is flowing. A reduced flow may suggest BPH.
  
  
• Cystoscopy. A thin tube called a cystoscope is inserted through the opening of the urethra (the canal that carries urine out of the body) in the penis. It contains a light and a lens that allows the physician to see the inside of the urethra and the bladder and to determine the size and state of the prostate gland. A local anesthetic jelly is used to reduce discomfort.
  
  
• Urodynamic studies. A catheter is inserted into the urethra and water is injected into the bladder to check internal bladder pressure and to determine how effectively the bladder contracts.
  
  
• Biopsy. Sometimes the urologist may want to take a tissue sample from the prostate gland to verify the diagnosis or to rule out cancer.

A urine test may be performed to check for infection or for blood in the urine and to rule out other causes of pelvic pain, such as prostatitis.

Researchers have developed a new blood test for the JM-27 gene, a marker of severe BPH. It has not yet been approved by the U.S. Food and Drug Administration.