Stress is not a factor that causes an increase in PSA levels, advises the American Cancer Society. Doctors administer a blood test to check PSA, or prostate-specific antigen, levels to screen for prostate cancer, states the National Institutes of Health.
Cancer is not the only cause of elevated PSA. Levels naturally increase with age, ejaculation and medications that increase testosterone, states the American Cancer Society. An enlarged prostate and inflammation or infection of the prostate gland might also lead to high PSA levels.
There is a 25 percent chance that a man has prostate cancer when blood PSA levels rise above 4 nanograms per milliliter and a 50 percent chance when levels rise above 10 nanograms per milliliter, states the American Cancer Society. If a man's blood test reveals high PSA levels, doctors may order a biopsy to positively diagnose or rule out prostate cancer.