Prostate nodules can be caused by BPH or by prostate cancer. Prostate-specific antigen is elevated in patients with prostate diseases such as prostate hyperplasia and prostate cancer, but the specific values behave differently. 1. Prostatic hyperplasia: the elevation of prostate-specific antigen in patients with prostatic hyperplasia generally does not exceed 4 ng/ml. In patients with prostatic hyperplasia, the proportion of elevated prostate-specific antigen is low and the value of elevated prostate-specific antigen is small, among which the proportion of free prostate-specific antigen is high, and the degree of elevation is often positively correlated with the volume of the prostate gland. 2. Prostate cancer: prostate cancer patients usually have prostate-specific antigen more than 4 ng/ml. with the progress of the disease, prostate-specific antigen tends to increase linearly. Patients with elevated prostate-specific antigen need to consult a doctor in time and receive timely treatment through detailed examination to clarify the cause of the disease.