Several clinical or laboratory tests can help the urologist:
Diagnose the cause of the urinary problem
Determine the best course of treatment
Generally, the urologist will test your blood to assess kidney function and the level of prostate specific antigen (PSA).
PSA is a protein present in the normal prostate gland as well as in enlarged prostates (BPH) or those in any stage of prostate cancer. A high PSA in the blood serves as a chemical marker for BPH as well as prostate cancer.
If your PSA is elevated, your urologist may recommend a transrectal ultrasound examination and a biopsy to distinguish between the two possibilities of prostate enlargement and prostate cancer
Digital Rectal Exam (DRE)
After putting on a lubricated glove, the physician gently inserts a finger through the anus into the rectum and assesses the size and hardness of the prostate gland. This exam is done when prostate enlargement is suspected or as part of an annual physical examination.
Urinary Flow Rate Study
This technique, which is used to detect an obstruction of the urethraand bladder neck, is widely used in the diagnosis of BPH. In the simplest form of this study, a recording is made of the flow rate during urination into a special device.
However, while a urinary flow rate study can indicate an obstruction, it cannot provide a definitive diagnosis of BPH. Many other variables affect flow, including a weak bladder contraction.
A pressure-flow study is more diagnostic but involves catheterization of the bladder. It is often performed in cases in which there is still doubt about the diagnosis and particularly where surgery is planned.
Intravenous Pyelography (IVP)
This test is performed only in cases complicated by a finding such as blood in the urine. Following intravenous injection of a dye, an x-ray of the urinary tract is made. Because the presence of the dye makes the urine visible on x-ray, the point of obstruction or narrowing of the urinary tract can be identified.
An instrument called a cystoscope is inserted through the urethral opening of the penis and visually guided through the urethra to the bladder. This test can be performed in the doctor's office, using a local anesthetic. During cystoscopy, an assessment is made of the size of the prostate gland, the degree of urinary tract obstruction, and its precise location.