What is the difference between PSA and free PSA?

What is the difference between PSA and free PSA? Do I need to have both tests?


Whether you need both tests really depends on your individual situation. That’s why this question generates so much debate and confusion.

PSA, a protein produced by prostate gland cells, circulates through the body in two ways: either bound to other proteins or on its own. PSA traveling alone is called free PSA. The free-PSA test measures the percentage of unbound PSA; the PSA test measures the total of both free and bound PSA.

Prostate cancer can raise PSA levels, but so can other conditions. These include an enlarged prostate, prostatitis, and advancing age. In fact, studies have shown that about 75% of men with an elevated PSA do not have prostate cancer. To determine which men actually have cancer and which don’t, physicians traditionally perform a biopsy. Undergoing a biopsy isn’t as traumatic as surgery, but it does cause discomfort and can provoke anxiety.

Rather than subject everyone with an elevated PSA to a biopsy, some urologists measure free PSA in patients with a total PSA level between 4 ng/ml and 10 ng/ml. Studies have shown that men with a total PSA in this “gray area” and a free PSA greater than 25% are more likely to have a benign condition than to have cancer, making a biopsy unnecessary. Men with a total PSA in the same range and a free PSA below 10% need to have a biopsy. More likely than not, they have prostate cancer (see table below).

In some cases, men with a “normal” PSA actually have cancer, but that low PSA doesn’t prompt a biopsy. A low PSA and a low percentage of free PSA, however, probably would. That’s why some doctors automatically order both tests at the same time. I tend to order a free-PSA test when a total PSA yields borderline results and when the PSA seems to be rising quickly, even if the actual number is relatively low. So, while the free-PSA test isn’t essential, the results may sway your decision on whether to have a biopsy when combined with other tests. In the future, other tests may help determine whether changes in PSA are driven by cancerous tissue or benign causes.

Probability of finding prostate cancer based on % free PSA in men with a total PSA between 4 ng/ml and 10 ng/ml

% free PSA Probability of prostate cancer
0%–10% 56%
10%–15% 28%
15%–20% 20%
20%–25% 16%
Greater than 25% 8%
SOURCE: Journal of the American Medical Association, May 20, 1998.

Originally published April 2009; last reviewed March 21, 2011.

Karl Isabelle

I am a man of 66 yrs old. I just had a Total PSA & a Free PSA test. The result has shown the following:
T-PSA Result is 73.50
F-PSA Result is 5.15

As I am a bit confused about this result so I would like to have your advice if I have a risk of a prostate cancer.

Grateful to give me your opinion about this result.

Waiting on your prompt reply.



I am a man of 55 years old , I just had a total PSA & free PSA test , the result is as follows:
Total PSA is 3.232ng/ml.
Free PSA is 0.845 ng/ml.
Please advise me if i have a risk of prosate cancer.
Thanks in advance , looking forward your opinion,
Thank you,

Ron Adair

I have a total PSA of 5.3, and a free PSA of .34, and a Percent Free PSA of 6.04. Can you advise me of the risk factor?

Thank you very much,


Robert Kocher

I have been having prostate and PSA exams since 2003. My PSA on the first exam was 4.2. The doctor did 12 biopsies found nothing and was diagnosed as acute prostatitis. I was given Levaquin for 10 days and started three month follow-up exams. The PSA went down to 3.1 in 12/2004 then spiked to 7.4 in June 2005. August 2005 more biopsies, found nothing diagnosis chronic inflammation and was given Cipro for 10 days. Resulting PSA went down to 3.4 by 11/2006 and was 6.3 in 12/2010. PSA then went to 6.8 in 08/2011. More biopsies, no malignancies again. PSA last test 06/2014 was at 6.9 up from 5.8 in January 0f 2014 and free PSA at 10% down from 11%. Doctor wants to do biopsies. I am inclined to ask for a prescription for 10 days and then have the PSA redone again in September. What is your opinion. I will be 67 in November. My father lived to 82 years and died of bone cancer.


I am a 48 year old man. My PSA has been fluctuating over the past four months from 6.8 to 4.2 to 3.6 to 4.6. However, each of the four times I have been tested my “free PSA” has been 0. (Yes, zero). I have been to two nationally recognized prostate cancer centers in southeast Michigan, but no one has ever seen a consistent “free PSA” of 0. I have a biopsy scheduled in 2 weeks.

Any thoughts you may have would be appreciated.



I am 72 years old and have been diagnosed with andenocarcinoma in one lobe of the prostate. The size of the tumor is 1.2mm with a gleason score of 6. I also have an enlarged prostate that has weakened my urine flow. This has improved after the Urologist put me on Lucrin hormone treatment for six months. I am on my second dose. I just had my PSA done and the total PSA is 2.35 with free PSA at 1.01 and a percentage of free PSA at 42.9. This high percentage is of great concern to me. Could the high percentage be as a result of the Lucrin hormone theraphy. My testosterone from Lab result is 0.20
Can you please give me your thoughts on the above. Thank you. Richard

Samuel Tso

I am a 65 years old man.

I had my first PSA tested in Jun 2008 and the results were Total PSA: 5.8 ng/ml and Free PSA:1.17 ng/ml. U/S prostate (transretal) followed by Trus Guided Prostate Biopsy were performed within two weeks from PSA test. U/S showed enlarged Prostate gland measurement 6.1×3.4×4.1 cm (TDxAPxCC). There was mainly hypertrophy of the central zone, suggesting benign prostatic hyperplasia. No focal lesin is seen in the peipheral zone. The contour of the prostat gland appears smooth. Biopsy of the protstae gland was perfomred and the procedure was unremarkable.

More than ten PSA tests were conducted from 2008 to end 2012 the Free PSA fluctuated from 5.7 to 7.8 and Free PSA from 0.98 to 1.41. In Aug 2013 PSA went up to 8.48 and in Jun 2014 PSA went up to 9.59, the doctor suggests to peerform a Biopsy. I am very concerned to do another Biopsy and would be grateful to have your advice by return.

Thanks a lot.

10 Aug 2014

Howard Himelstein

I have just been diagnosed with Pca…My Gleason is a 3+3=6, T1c, Total PSA is .65, psad is .01, but my free psa is .11 and my PSA3 test is 58.4…I read in Patrick Walsh’s book that if you have a free PSA under 15, there is an almost certain chance that one’s cancer is the aggressive type. When I asked my doctors about that they told me not to be concerned as it doesn’t apply to my situation. Does anybody know why it doesn’t? Can’t seem to get a solid answer from my uros…

PS – just had an Onotype DX test and it came back at a good and low 15.


I am 71 and I was diagnosed with prostate cancer last December (Gleason 6; 1 core less than 10%). I have been taking Avodart for BPH for several years. My total PSA has been around 1.9- 2.5 for several years). The latest PSA test has the following reading:
PSA % Free= 28%
PSA Free: 0.39 (ng/ml)
The test result does not list the total PSA. Doing the math I calculated the total PSA as 1.39 ng/ml. Please confirm if my calculations are correct: (0.39*100)/28.

Thank you for your help,



I live in Brazil, 58 years old, and my blood test revealed the following:
Total PSA = 0.76 ng/ml
Free PSA = 0.42 ng/ml
Free/Total Ratio = 0.55
GP’s NOTE: “Results suggest BPH: Free-Total PSA ratio > 25%. Send to urologist.”
Thank you.


I am a man73years old and living in Iran .I had a total PSA and free PSA test .The result is as follows :
Free PSA 0.4
PSA 1.41
Free psa/PSA 0.28 ratio
Will you pleas advise me if i have the risk of prostate cancer?
thanks in advance .looking forward your opinion .
best regards : REZA


60 yo excellent health, fitness. lifestyle and diet. No meds except TRT since 2006. Annual DRE always completely non-remarkable.

2006 – 2012 PSA = 1.8
2013 PSA = 2.1 Free = .21 so 10%
2104 PSA = 2.8 Free = .28 20 10%

Active surveillance or biopsy here?


i am 53 years
my prostate is calsificate and shows bellow test
P.S.A =0.362
FREE PSA =0.154
free psa ratio =0.43
pls guide me
thank you


I am 44 years old I have a total psa of 5.9 with a free psa of 0.8 and a 0.14 free psa ratio . I am confused please advise me of what this means


I am approaching 59 and healthy person. My latest test results were Total PSA of 2.33 and Free PSA of 0.44 (free PSA first time tested). My DRE check up with Urologist specialist was normal. My Total PSA over the years have been around 2.5 with little change apart from one case where the total PSA went up to 3.3 and down again to 2.6 and then 2.33. Shall I continue as it is testing once a year? My consultant reassuring that everything is normal. Also can diet help to improve results effectively? Many thanks.


I am 71 years old. in June 2014 my total PSA was 4.48 and today it was 4.05. The free PSA is 0.96 and the ratio is 23.73%.
Should I be concerned?

Vijay Mahadeo Bartakke

I am a man of 71 yrs. old. RecentlyI had a Total PSA & a free PSA test. The results are:

PSA-Serum by CMIA 5.145
Free PSA serum by CMIA 1.54
Free/Total PSA ratio 29.99

I had undergone thrice TURP in 1996,1999 & 2009. With histopathological reports ware negative.

PSA concentration has remained elevated since 2006.

Please note that I had TURS guided Biopsy in Feb.2014. Which result was negative.

So I am very much confused and anxious. I am very grateful to have a advice and opinion about the results.

Waiting for your prompt reply.

Thank you,

Vijay M. Bartakke


Hi , iam 67 years , my psa diagnostic is. Total. 3.260. Free 0.88. Free/total. 27.0% laboratory of american university of beirut. Please let me know your opinion about this result. Espcially for free psa which was befor one year 0.78. Laboratory evarage up to 0.72. ,please is it bad indication. Thank you in advance ,best regards. Roni


I have an enlarged prostate and PSA readings between 5-6.0 on average. My FPSA is usually about 1 and % varies between 16-22%. I am 64 and had one biopsy 4 years ago but want to avoid more! My last test had a crazy high FPSA reading a little higher than my PSA of 5.3 so my % is 100% meaning no cancer risk??!!! Could this FPSA be so high due to other factors like a mild infection etc. ..maybe a follow up test next month to see if FPSA is back to normal??
Thks for any advice.


Hi, i,m 64 and 18 months ago my psa was around 0.70 for years and then 6 months it went to 2.1 and stayed there for 3 months now it went to 3.3 with a free psa of 0.4 ng/ml, 25% i have the normal symptoms of bph and my rectal is enlarged but smooth. I drink 2 gallons of milk a week and lots of eggs and cheese and dairy. Do i need a biopsy? Thank you


Hi, I am 65 yrs old and saw a urologist for hemospermia.that I had for about 2 months. He did a psa which came back at 5.3. It had been 3.5 about 18 months prior. He said to give it time. I returned in 2 months and the hemospermia seems to have cleared up . He took a new Psa after a DRE that was normal and the psa was 7.2. My Free Psa was 19%. His recommendation was to take 5mg of Proscar for 6 months and if psa does not go down at least 50% than a biopsy would have to be done. My concern is that the PSA rose so quickly in 2 months. I also have BPH. Size 65 grms. Is it ok to wait 6 months? Thank you


Hi, I am 42 years old. My PSA has fluctuated for the last 10 years between 1.9 and 3.2. The PSA was 3.2 and my free PSA % was 20.3% on 12/12/13, at that time the doctor prescribed levoquin and my PSA went down to 3.0 and my % to 26.7%. I still felt some discomfit and irritation in my prostate, so my doctor kept me on the levoquin for another 60 days. My PSA as of 1/21/15 is 2.6 (which I am very happy with), but my free % is now 18.8%, which is scaring me. I have never had any biopsies, my doctor has shied away due to my age and potential risk. However, now I am concerned, should I be?

Also, what is an Onotype DX test and would this be a good test for me to take?

Thank you for your help!

Mark Oliver

hello, I am 47 and my PSA is 4.6, I am so scared and depress. I am schedule for a biopsy on Feb. 16, 2015. I have a history of prostatitis 8 yrs. ago. But then my PSA was .04. Any ideas wil be helpfully.

Gary Hoga

I am a little confused. According to the article that preceeded this blog 2 speciic tests were discussed.

Total PSA
Free PSA

In a number of the comments posted I see reference to numbers for %Free PSA.

It has always been my understanding that Free PSA is expressed as a percentage of total PSA. i.e., .20 = 20% of Total PSA is free. Meaning if I had a biopsy done there is a 20% probabilty (according to the chart) that cancer would be found. Am I correct in my assumption?


Hi I had a psa test in January 2015 and it came back as 10.1. This was a total psa not free psa i. I had follow up total psa last Monday and it was 1.5. Can anyone explain?
Bit embarrassed to say but for first test I had had sex an hour before? Could this explain such a variation? I had a psa done 2/years ago and it was 1.7. I am 57 years old

Charlene Crosthwaite

My husband had a PSA test in Oct. 2014. Total PSA…7.06 with Free PSA of 19%. DRE showed prostate enlarged. Urinary and ED issues. Dr. prescribed Cialis 5 mg every other day and 0.4 mg Tamsolusin daily and to have test repeated in January 2015. Total PSA…6.84 with Free PSA of 13%. Husband is 75 years old. His older brother also had prostate cancer several years ago. Dr. never mentioned Free PSA, but gave another appointment for November 2015, 9 months from now. I think that is a big drop in the Free PSA. Am I wrong to be worried about the Free PSA result?

Ron Davis

I am 73 years old and my PSA is 2.4 and my PSA free is 16%. My Prostate is moderately enlarged and should I be concerned and if so what is your suggestion on my next step. Thanks

Azzam Jarrar

I am 64 years and my PSA is (3.98 ) and Free PSA is( .261) and PSA ratio is(.o7)
what is my next step should be.. thanks

Sandeep Gupta

I am 49 years old man. I have a total PSA of 5.07, and a free PSA of 1.11, and % free PSA of 21.89. Please advise whether I should go for Prostrate biopsy or not.

Roger Smith

I was beenDx with agressive prostate CA in September, 2014. I have been on alternative treatment since then. No chemo,radiation or surgery.
My PSA then was 9.0ug/L,
Free PSA 1.2ug/L and
%Free PSA 14.0%.
Now on the 13/02/2015 the values are as follows:
Total PSA-5.1ug/L
Free PSA: 0.88ug/L
% Free PSA: 17.3%
Please can you explain these figures to me, am I going in the right direction?


My 83 yr old father has just been biopsied and diagnosed with prostate cancer. I learned his PSA was 10 at least 6 months ago and this 6 month check has jumped to 17. After researching and reading posts I am beside myself wondering why he was not biopsied long before now. I am in another state and my dear dad is a private person. He does not want me to go with him to his dr. Appt. after the scan happens next week to see if it has spread. I think he needs an advocate to say that he is important, loved and worth the treatment. Does anybody have any knowledge or experience that can help me ask the right questions to get the right care for my beloved dad.


A 55-year-old man whose is free PSA and total PSA 0.31 ug/L and 1.5 ug/L respectively is concerning about if he needs to have a biopsy. Three years ago, three polyps were found out, and diagnosed that all polyps were benign. Therefore, that patient has PSA testing every year to make sure a biopsy is needed once those polyps become malignant.

So, could any experts here tell me if he needs a biopsy now?

Thank you so much!

κουκακης ηλιας



My husband is 52, has been on fluctuating doses of testosterone ink for 1.5 yr. PSA last April 2.1- in July 2.8- in Feb the following yr-PSA 2.79- free PSA 0.51 and free psa % 18.3. Hx- dad had prostate ca. Bx scheduled 4/3. Nervous. Suggestions?


had my prostate removed in 2007….ORIGINAL PSA WAS 23.9 HAD PROSTATE REMOVED AND RADIATION TREATMENTS. then it started to rise after a few months to 3.8, luprin shot reduced…..second shot given and then after 0.0 in 2013 it finally budged to 0.05> now it is 2015 ….what are your thoughts? I am getting another test soon….does history tell you I am ok? Phil

Gerald Carter

I recently moved and currently looking for a new Urologist. I am 66 years old and found a new Family Physician finally after a year. Both my Dad, brother, and a cousin had prostate cancer. I had two biopsies in the past, but were negative. I have also been treated in the past with Levo & cipro. My current PSA level is 15.9 and the FPSA is 4.0. Would a repeat biopsy be warranted at this time based on family history and current values? Both my Dad and brother have died, Dad from additional complications (80) and my brother at 60. Thank you

Dr. leo Karkas

Men over 50 are concerned about what they hear of the possibility of prostatic cancer. When to screen, when to perform a rectal exam and when to undergo prostatic biopsies and also at what intervals. Bad biopsies may give a whip to the prostate to develop CANCER.
When the PSA is in the gray zone between 4.00 and 10.00 there is no need for biopsies or medications if the free PSA level is not high and the ratio above 25.
One of the signs to remember for further investigations is the steadily rising PSA from yeah to year by one percent.
This is to say that anxiety in men should be controlled by good advice rather by extensive invasion of privacy. However trouble in urination and alike symptoms and abnormal values of free PSA and any ratio between the free PSA and the total less than 10 become a compulsory rule for investigation.

Dr. leo Karkas

Men over 50 are concerned about what they hear of the possibility of prostatic cancer. When to screen, when to perform a rectal exam and when to undergo prostatic biopsies and also at what intervals. Bad biopsies may give a whip to the prostate to develop CANCER.
When the PSA is in the gray zone between 4.00 and 10.00 there is no need for biopsies or medications if the free PSA level is not high and the ratio above 25.
One of the signs to remember for further investigations is the steadily rising PSA from yeah to year by one percent.
This is to say that anxiety in men should be controlled by good advice rather by extensive invasion of privacy. However trouble in urination and alike symptoms and abnormal values of free PSA and any ratio between the free PSA and the total less than 10 become a compulsory rule for screening and investigation.

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