A PSA test is a blood test that measures the amount of prostate specific antigen (PSA) in the blood. In men, PSA is made by the prostate and is found naturally in small amounts in their blood. However, a raised PSA level can sometimes be a sign of prostate cancer and other conditions.
Prostate cancer is common in older men. Unlike many cancers, you can have prostate cancer for many years without any symptoms. This is because most prostate cancers grow very slowly and don't spread to other parts of the body. Therefore it may never need treatment. By the age of 80, half of all men will have some cancer cells in their prostate, but only 1 in 30 will die from it.
There is no evidence that a PSA screening programme for all men would cut deaths from prostate cancer. This is because around one fifth of men who have prostate cancer don't have a raised PSA level. Also, around two in three men who have a raised PSA level don't have prostate cancer. A slightly raised PSA level can also be a sign of a prostate infection, or enlargement of the prostate.
Therefore, your GP won't suggest that you have a PSA test unless you have other symptoms of prostate cancer such as urgent or very frequent need to urinate, or difficulty starting and stopping urination.
If a test reveals high levels of PSA in your blood, a biopsy (a small sample of tissue) will need to be taken to confirm if you have prostate cancer, and if it is likely to grow and spread to other parts of the body.