Abnormal PSA

Prostate-specific antigen (PSA) is a protein produced by cells within the prostate gland. It is important in the early detection of prostate abnormalities, including cancer.

Regular PSA testing assists healthcare professionals in monitoring prostate health and making informed decisions about further diagnostic or treatment options.

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What is PSA?

The primary function of PSA in the body is to liquefy the semen, facilitating the movement of sperm during ejaculation. This liquefaction process is vital for reproductive success, ensuring that sperm can move freely and efficiently. While a small amount of PSA enters the bloodstream, elevated levels can indicate potential prostate issues. A blood test measures these levels, aiding in the early detection of prostate conditions.

Causes of Elevated PSA Levels

  • Age-related increase: As men age, the prostate gland naturally enlarges, leading to a gradual rise in PSA levels. This is a normal part of the aging process and doesn’t necessarily indicate a prostate condition. However, older men are advised to have regular PSA tests as a precautionary measure.
  • Benign prostatic hyperplasia (BPH): BPH is a non-cancerous enlargement of the prostate gland. As the prostate enlarges, it can produce more PSA, leading to elevated levels in the bloodstream. BPH can cause urinary symptoms such as frequent urination, difficulty starting and stopping urination, and weak urine flow.
  • Urinary Tract Infection (UTI): UTIs can cause inflammation and irritation of the prostate gland. This inflammation can lead to a temporary increase in PSA levels. Once the infection is treated, PSA levels typically return to normal.
  • Prostatitis: Prostatitis refers to inflammation of the prostate gland, which can be caused by bacterial infections or other factors. This inflammation can result in elevated PSA levels. Symptoms of prostatitis can include pain in the pelvic area, difficulty urinating, and flu-like symptoms.
  • Recent ejaculation: Sexual activity, specifically ejaculation, can cause a temporary spike in PSA levels. This is because the activity stimulates the prostate, leading to a release of additional PSA into the bloodstream. It’s recommended to abstain from sexual activity for 24-48 hours before a PSA test to avoid skewed results.
  • Parathyroid hormone influence: Some studies suggest that elevated levels of parathyroid hormone, which regulates calcium in the blood, can be associated with increased PSA levels. The exact relationship between the two is still under investigation.
  • Prostate injury: Any trauma, injury, or invasive procedures involving the prostate can lead to a temporary rise in PSA levels. This includes procedures like a biopsy, catheter insertion, or even vigorous physical activities that impact the groin area.
  • Surgical procedures affecting the groin: Surgical interventions, especially those involving the prostate or surrounding areas, can elevate PSA levels temporarily. Inform the healthcare provider of any recent surgeries or procedures before undergoing a PSA test.

Understanding the various causes of elevated PSA levels helps for accurate diagnosis and treatment. While elevated PSA can be indicative of prostate cancer, it can also be due to several benign conditions. Regular monitoring and consultation with your urologist can provide a comprehensive assessment.

PSA Test Procedure

The PSA test is a simple blood test used to measure the concentration of prostate-specific antigen in the bloodstream. Here’s a step-by-step breakdown of the procedure:


  • It’s recommended to abstain from ejaculation for 24-48 hours before the test as it can temporarily raise PSA levels.
  • Inform the doctor of any medications you’re taking, as some drugs can affect PSA levels.
  • It’s also advisable to let the doctor know of any recent procedures or infections, as these can influence the PSA reading.

Blood Sample Collection

  • The patient will be seated or will lie down on a reclining chair or bed.
  • A needle will be inserted into a vein, usually in the bend of the arm, and a small amount of blood will be drawn.
  • Once the blood sample is collected, the needle will be removed, and a small bandage or cotton ball will be placed on the puncture site.

Laboratory Analysis

  • In the lab, technicians will analyse the blood sample to measure the concentration of PSA.
  • The results are usually reported in nanograms of PSA per millilitre (ng/mL) of blood.

Receiving Results

  • The results are typically available within a few days.
  • A urologist will interpret the results, considering various factors like age, prostate size, and any other relevant medical history.
  • Depending on the PSA level and other factors, the doctor may recommend further tests or procedures.


  • If PSA levels are elevated, the doctor might suggest repeating the test to confirm the results.
  • Additional tests, such as a digital rectal exam (DRE) or prostate biopsy, might be recommended based on the PSA results and other clinical factors.

Interpreting PSA Results

Understanding PSA Levels

PSA is measured in nanograms per millilitre (ng/mL). The specific “normal” range can vary, but traditionally, a PSA less than 4.0 ng/mL has been considered normal. However, some doctors now use a threshold of 2.5 or 3.0 ng/mL.

Age-Specific Ranges

PSA levels tend to rise with age. Therefore, age-specific ranges have been developed to interpret PSA levels more accurately:

40-49 years: 0-2.5 ng/mL

50-59 years: 0-3.5 ng/mL

60-69 years: 0-4.5 ng/mL

70 and older: 0-6.5 ng/mL

PSA Velocity

It’s not just the absolute value of the PSA that’s important, but also how quickly it changes. A rapid rise in PSA levels over time, known as PSA velocity, can be indicative of prostate cancer even if the absolute values are not above the traditional threshold.

PSA Density

This considers the size of the prostate. Two men might have the same PSA level, but if one has a larger prostate, the density (PSA level divided by the volume of the prostate) would be lower, which might be less concerning.

Free vs. Bound PSA

PSA exists in two forms in the blood: free (not bound to proteins) and bound (attached to proteins). A lower percentage of free PSA can indicate a higher risk of prostate cancer. Typically, if the PSA is between 4 and 10 ng/mL, a free-to-total PSA ratio is calculated. A ratio below 10-15% means a higher risk of prostate cancer.

PSA and Prostate Cancer

Elevated PSA levels can be indicative of prostate cancer. However, a high PSA alone doesn’t confirm cancer. It merely signals the need for further tests. Biopsies, MRIs, and other diagnostic procedures are often used in conjunction with PSA tests to determine the presence of prostate cancer.

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for Your Urological Conditions


Regular monitoring of PSA levels is instrumental in the early detection of prostate conditions. While elevated PSA can indicate potential issues, consider other factors and undergo additional tests for an accurate diagnosis. Individuals are encouraged to consult with healthcare professionals for a thorough evaluation and personalised advice.


Dr Lee Fang Jann image

Dr Lee is a urologist and kidney transplant surgeon with a broad-based expertise of all urological disorders

He has subspecialty focus on men’s health and male infertility, and special interest in minimally invasive prostate enlargement therapy and kidney stone treatment. Dr Lee has received numerous awards for service excellence such as the Service With A Heart Award (2006-2008, 2011) and the Singapore Health Quality Service Award (2016).

  • Bachelor of Medicine and Bachelor of Surgery (Singapore)
  • Membership of The Royal College of Surgeons (Edin)
  • Master of Medicine (Surgery) (Singapore)
  • Fellowship of the Academy of Medicine (Urology)
  • Clinical fellowship at Oxford Transplant Centre in the UK

Prior to entering private practice, Dr Lee served in the public sector for 16 years at SGH, where he initiated dedicated clinics evaluating and treating patients with complex men’s health and fertility issues. He also led the Renal Transplant Program and laparoscopic donor nephrectomy service as Surgical Director.

Apart from clinical work, Dr Lee is active in academia and believes in the importance of grooming the next generation of doctor. He was Senior Clinical Lecturer at NUS’ Yong Loo Lin School of Medicine and currently, Adjunct Assistant Professor at the Duke-NUS Medical School. Dr Lee is also regularly invited to share his experiences locally and regionally through lectures, workshops and surgical demonstrations.

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    Frequently Asked Questions

    Are there any alternative tests to PSA for detecting prostate conditions?

    Yes. Besides the PSA test, the digital rectal exam (DRE) is commonly used. Additionally, newer tests like the PCA3 urine test and the PHI (Prostate Health Index) are emerging as alternatives.

    How does diet and lifestyle impact PSA levels?

    Diet and lifestyle can influence prostate health. High-fat diets and sedentary lifestyles may increase PSA levels, while diets rich in fruits, vegetables, and omega-3 fatty acids might have protective effects.

    Is there a genetic predisposition to having higher PSA levels?

    Some studies suggest a genetic component to PSA levels, with certain genetic markers potentially leading to higher PSA. Family history of prostate conditions can also influence levels.

    Is there a correlation between testosterone levels and PSA?

    Elevated testosterone levels can lead to increased PSA levels, as testosterone stimulates the prostate gland to produce more PSA.

    How do other conditions, like diabetes or heart disease, impact PSA readings?

    Conditions like diabetes may result in lower PSA levels, while medications for heart disease, like statins, can influence PSA readings. Consider these factors when interpreting results.

    Are there any known side effects or risks associated with frequent PSA testing?

    Frequent PSA testing can lead to overdiagnosis and overtreatment, potentially resulting in unnecessary procedures and their associated risks. Balance the benefits and risks of regular testing.