Prostate Specific Antigen (PSA)
PSA is a natural protein that is made by the prostate and is found in semen. A small amount of it leaks in to the blood stream in all men. Some conditions increase the amount of PSA that leaks into the blood stream and the serum PSA increases in men who have a large prostate, men who have and enlarged prostate and men who have prostate cancer.
The decision to have a PSA blood test is a personal one. Opinion within the medical profession is divided about who should have a PSA blood test.
Some doctors think that PSA gives us the best available chance to reduce the number of men who die of prostate cancer each year - currently nearly 11000.
Other doctors think that having a PSA blood test will cause many men to have tests and treatments from which they will not derive any benefit.
The PSA blood test does not say for sure if a man has prostate cancer - this usually requires further investigation - usually a biopsy on the prostate.