Prostate-specific antigen (PSA), is a glycoprotein produced by cells of the prostate that remains free in the blood. A free PSA test measures the amount of unbound prostate-specific antigen in the blood, which helps physicians to identify problems such as prostate inflammation or tumor. Levels of PSA rise in conditions such as prostate cancer and also in benign prostatic hyperplasia (BPH). Monitoring free PSA is useful for detecting metastatic or chronic disease in patients receiving anti-prostate cancer therapy. If the levels of PSA are elevated after treatment, it indicates the recurrence of the disease. Now book your PSA test at an affordable price, with a home collection service from Thyrocare.