PSA Test Explained: Thinning or weakening of the stream of urine in men is often ignored considering it normal, but it can be an early sign of a serious problem related to the prostate gland. In conditions like enlarged prostate, swelling in the prostate or prostate cancer, the urine stream may become thin, there may be problem of frequent urination or difficulty in starting urination. Dr. Amarendra Pathak, a urologist at Sir Ganga Ram Hospital, Delhi, has said in a video uploaded on his YouTube channel that if a person continues to have these symptoms, then he should get Prostate Specific Antigen (PSA) test done. This is a simple blood test that measures the level of a protein called PSA in the blood. An increased level of PSA may indicate an abnormality in the prostate. However this is not always a sign of cancer.