Understanding Prostate Health: PSA Levels Chart and Antigen Explanation
Ian C. Langtree - Writer/Editor for Disabled World (DW)
Published: 2015/02/14 - Updated: 2025/01/27
Publication Type: Charts, Graphs, Tables
Topic: Prostate Cancer - Publications List
Page Content: Synopsis - Introduction - Main
Synopsis: This article provides a guide to the PSA (Prostate-Specific Antigen) test, crucial for screening and monitoring prostate cancer, which is particularly relevant for men, including seniors and those with disabilities who might face challenges in accessing regular health check-ups. It details how the PSA test measures the level of PSA in the blood, explaining what high or low levels might signify, including the possibilities of both false positives and false negatives. The article emphasizes the importance of informed decision-making regarding PSA testing, discussing its benefits in early cancer detection and potential drawbacks like overdiagnosis and overtreatment. It also includes practical advice on preparing for the test, interpreting results, and considering additional tests like a digital rectal exam or biopsy, making it an invaluable resource for understanding and navigating prostate health care decisions - Disabled World (DW).
Introduction
The prostate is a walnut-sized gland between the male bladder and the penis. The prostate is just in front of the rectum. The urethra runs through the center of the prostate, from the bladder to the penis, letting urine flow out of the body. The mean weight of the normal prostate in adult males is about 11 grams, usually between 7 and 16 grams. It surrounds the urethra just below the urinary bladder and can be felt during a rectal exam.
Focus
Prostate-specific antigen (PSA) is a protein made by the cells of the prostate gland. PSA is mostly found in semen, but it is also normal to find small amounts of PSA in the blood of healthy men.
A PSA test measures the amount of PSA in the blood. Elevated PSA levels may indicate prostate cancer, a non-cancerous condition such as prostatitis, or an enlarged prostate.
How is a PSA Test Done?
The prostate-specific antigen test is determined by a simple blood test and is often performed on males 50+ during regular doctor checkups.
The PSA level in your bloodstream is measured in nanograms per milliliter (ng/mL).

What are Normal Results for a PSA Test?
The normal PSA serum concentration ranges between 1.0 and 4.0 ng/mL. However, since the prostate gland generally increases in size and produces more PSA with increasing age, it is normal to have lower levels in young men and higher levels in older men. The PSA level also depends on ethnicity and family history of prostate cancer.
Other than the single reading, the changes in PSA numbers on an annual basis (also referred to as PSA-velocity) also play a role in decision-making about the PSA marker. The normal increase of less than 0.75 ng/mL is used to help determine whether levels may be suggestive of disease and to counsel men on management.
A man 50 to 59 years of age with increased PSA levels from 0.5 ng/mL to 2.5 ng/mL may cause greater concern despite the "normal" value at that time.
The PSA is not a perfect test but it can aid in detecting prostate cancer. The normal PSA value is usually stated to be less than 4.0. However, because of the fact that benign enlargement of the prostate gland tends to occur as men get older, an age-adjusted scale has been developed:
- 0 - 2.5: Normal for a man 40-50 yrs.
- 2.5 - 3.5: Normal for a man 50-60 yrs.
- 3.5 - 4.5: Normal for a man 60-70 yrs.
- 4.5 - 5.5: Normal for a man 70-80 yrs.
PSA Levels Are NOT a Diagnostic of Cancer
The standard for identifying prostate cancer is the prostate biopsy, collecting small prostate tissue samples and identifying abnormal cells under the microscope. The total PSA test and digital rectal exam (DRE) are used together to help determine the need for a prostate biopsy. The goal of screening is to minimize unnecessary biopsies and to detect clinically significant prostate cancer while it is still confined to the prostate.
A PSA blood test can detect prostate cancer early but may not save lives.
Many prostate cancers grow slowly, so a PSA test may save the lives of some but cause others to have unnecessary surgeries or radiation treatment, which could cause lifelong problems such as erectile dysfunction or incontinence.
Men over 50 should talk to a doctor about their risk of developing prostate cancer and the benefits and risks of having a PSA test.
Age | <50 | 50 - 59 | 60 - 69 | >70 | (years) | ||||
---|---|---|---|---|---|---|---|---|---|
Cancer | No cancer | Cancer | No cancer | Cancer | No cancer | Cancer | No cancer | ||
5th percentile | 0.4 | 0.3 | 1.2 | 0.3 | 1.7 | 0.3 | 2.3 | 0.4 | (ng/mL) |
95th percentile | 163.0 | 2.5 | 372.5 | 4.7 | 253.2 | 8.3 | 613.2 | 17.8 |
If your doctor is concerned that you might have prostate cancer based on a PSA level or a rectal exam, a biopsy (a lab test of a small amount of tissue from the prostate) will be the next step. This is the only way to identify the presence of cancer positively.
NOTE: The "normal" reference ranges for prostate-specific antigen increase with age, as do the usual ranges in cancer.
Also See:
- PI-RADS: Prostate Imaging Reporting and Data System Chart: This article and table outlines the Prostate Imaging Reporting and Data System (PI-RADS), a critical tool for evaluating prostate cancer risk.
- Gleason Scores: What They Mean for Prostate Cancer: This chart illustrates the different Gleason scores, their associated cancer aggressiveness, metastasis risk, and treatment considerations.
Author Credentials: Ian is an Australian-born writer, editor, and advocate who currently resides in Montreal, Canada. He is the founder and Editor-in-Chief of Disabled World, a leading resource for news and information on disability issues. With a global perspective shaped by years of travel and lived experience, Ian is a committed proponent of the Social Model of Disability-a transformative framework developed by disabled activists in the 1970s that emphasizes dismantling societal barriers rather than focusing solely on individual impairments. His work reflects a deep commitment to disability rights, accessibility, and social inclusion. To learn more about Ian's background, expertise, and accomplishments, visit his full biography.