PSA (prostate-specific antigen) is a protein made by the cells of the prostate, and its level in the blood is used to assess the condition of the gland. The test is simple – one tube of blood from a vein – and it is the main tool for detecting prostate cancer early.
At the same time, PSA is one of the most frequently misinterpreted tests. A raised value does not mean cancer, and a normal value does not rule it out completely. That is why the result should be read by a urologist, together with the examination and your history.
What is the PSA test
PSA is an enzyme that makes semen more liquid; normally a small amount of it passes into the blood. When the structure of the gland is disturbed – by inflammation, an increase in size, mechanical irritation or a tumour – more PSA gets into the blood. This is why the marker is specific to the prostate, but not to cancer.
Total PSA is tested, and with borderline values free PSA as well – the fraction that is not bound to proteins. In cancer the share of free PSA is lower, so the free-to-total ratio helps decide whether a biopsy is needed. PSA density (the value in relation to the prostate volume measured on ultrasound) and the speed at which PSA rises over time also matter.
Approximate reference values
There is no strict line between “normal” and “abnormal”. As a rough guide for total PSA:
- below about 1 ng/ml in a man aged 45–50 – low risk and infrequent follow-up;
- up to about 3–4 ng/ml – the usual range, interpreted according to age and the size of the gland;
- above about 4 ng/ml, or a clear rise compared with previous results – a reason for further assessment;
- above about 10 ng/ml – the likelihood of cancer is higher, but inflammation and a large prostate are common causes here too.
A single raised value is never a diagnosis – it is a signal for the next step.
Symptoms for which PSA is tested
PSA is tested as a check-up in well-informed men from around the age of 50, and from 45 if a father or brother has had prostate cancer. The test is also needed if you have symptoms:
- a weak stream, straining, passing urine often and getting up at night;
- blood in the urine or semen;
- pain in the perineum, lower back or pelvis without a clear cause;
- monitoring of an already diagnosed enlarged prostate or after treatment for prostate cancer.
Painless blood in the urine needs to be checked within the next few days, and suddenly being unable to pass urine with a full bladder is an emergency – go to an emergency department or call 112 (the European emergency number).
Causes of a raised PSA and risk factors
Cancer is only one of the causes. More often PSA is raised by:
- a benign enlarged prostate – the larger the gland, the higher the PSA;
- acute or chronic prostatitis and urinary tract infections, which can raise it many times over for weeks;
- ejaculation in the last 48 hours;
- cycling, horse riding and other pressure on the perineum;
- a urethral catheter, cystoscopy or biopsy – the effect lasts for weeks;
- acute urinary retention.
A rectal examination raises PSA only slightly, but for accuracy the blood is taken before it or a few days afterwards. 5-alpha-reductase inhibitors, used for an enlarged prostate, lower the value by roughly half.
Diagnosis – how Dr Penev interprets the result
At the examination at the practice in Plovdiv or Karlovo, Dr Penev compares the value with your age, previous results, medicines and recent events that may have changed it. This is followed by a rectal examination and an ultrasound of the prostate to measure its volume and the urine left in the bladder, from which the PSA density is calculated. If there are signs of inflammation, this is treated first and the PSA test is repeated after 6–8 weeks. You can read more about the prostate check separately.
Treatment and next steps with a raised PSA
PSA itself is not treated – the cause is. If the value stays raised or keeps rising, the steps are:
- a repeat test with the right preparation;
- the free-to-total PSA ratio and PSA density;
- a multiparametric MRI scan of the prostate;
- if there are suspicious areas, a targeted biopsy, which is the only way to confirm or rule out prostate cancer.
Most men with a raised PSA do not have cancer. And if there is a tumour, finding it at this stage gives the widest choice of treatment options.
When to see a urologist
Book an appointment if you are over 50 and have not had a PSA test, if you are over 45 with a family history, if you have a raised result from a laboratory or if you have problems with passing urine. Bring all your previous results – the trend says more than a single value.
Prevention
The best prevention is regular follow-up according to your risk, not a one-off test. A healthy weight and exercise do not change PSA directly, but they are linked to a lower risk of aggressive prostate cancer.
A raised PSA is a reason for a calm and methodical assessment, not for panic. Book an appointment with Dr Penev in Plovdiv or Karlovo to go through the result together with a urologist and get a clear plan.
Frequently asked questions
Do I need to fast before a PSA test?
No, eating does not affect PSA and the blood can be taken at any time of day. However, avoid ejaculation and cycling for two days beforehand and mention any recent infection or procedure.
How often should I have my PSA checked?
If the value is below about 1 ng/ml at the age of 45–50, every few years is often enough; with higher values or risk factors, once a year. The interval is set individually.
A raised PSA in a young man – what does it mean?
In men under 40–45 the most common cause is inflammation of the prostate or urethra. Urine and prostate fluid are tested first, the inflammation is treated and the PSA test is repeated.
What should the PSA be after the prostate has been removed?
After a radical prostatectomy the PSA should be practically undetectable. A rise above about 0.2 ng/ml on two consecutive tests is regarded as a biochemical recurrence and calls for further assessment.
The information on this website is for general education and does not replace an examination and consultation with a doctor. If you have urgent symptoms, seek medical help immediately or call 112.