Understanding Age-Related Prostate Growth
As men get older, the prostate gland naturally undergoes a second phase of growth, beginning around age 25 and continuing throughout adulthood. This process is largely driven by hormonal changes, and by the time a man reaches his 70s, the prostate volume is generally larger than it was in his younger years. This noncancerous growth, known as benign prostatic hyperplasia (BPH), affects a significant number of men over 70, with some studies estimating a prevalence of 80% or more.
It is important to remember that a single 'normal' measurement does not exist, as size varies greatly among individuals. The reported average is a statistical mean, and many men in their 70s may have prostates larger or smaller than this figure without experiencing any problems. The size of the prostate is not necessarily an indicator of how severe any associated urinary symptoms might be.
How Prostate Volume is Measured
Healthcare providers use several methods to determine the size of the prostate, each with its own level of accuracy. The most common and accurate method for obtaining a precise volume is a transrectal ultrasound (TRUS).
Common Measurement Techniques
- Transrectal Ultrasound (TRUS): This involves inserting a small, lubricated probe into the rectum. The probe emits sound waves that create an image of the prostate, and the volume can be calculated with a high degree of accuracy using the formula for an ellipsoid (Length x Width x Height x 0.52). This is the most reliable method for precise volume measurement.
- MRI (Magnetic Resonance Imaging): An MRI can also provide detailed images of the prostate and surrounding tissues, allowing for an accurate calculation of the gland's size.
- Digital Rectal Exam (DRE): A doctor can perform a DRE by inserting a gloved, lubricated finger into the rectum. This allows them to manually estimate the size and feel the texture and shape of the prostate. While a useful clinical tool for a general assessment, a DRE is not a precise way to determine volume and can often underestimate the size of the prostate.
The Relationship Between Prostate Volume and PSA Levels
Prostate-Specific Antigen (PSA) is a protein produced by the prostate gland. PSA levels are measured with a blood test, and while they can be used to screen for prostate cancer, they are also affected by the size of the prostate. In older men, a larger prostate from BPH can cause PSA levels to rise, independent of cancer. This makes interpreting PSA test results more complex for men with an enlarged prostate.
Average PSA Ranges by Age for Men in their 70s:
- 70-79 years: A typical PSA range might be between 0.0 and 6.5 ng/mL. It is important to note that these are general guidelines, and a doctor will interpret test results based on individual health history, risk factors, and the overall clinical picture.
Comparison of Prostate Volume and Symptoms
It is a common misconception that prostate size directly correlates with the severity of urinary symptoms. A man with a moderately enlarged prostate might experience significant urinary difficulties, while another man with a much larger prostate could have no symptoms at all. This is because symptoms often arise from the prostate pressing on and constricting the urethra, rather than the gland's overall size.
| Feature | BPH (Enlarged Prostate) | Symptom Severity | Cause of Symptoms |
|---|---|---|---|
| Prostate Size | Variable, but typically larger (>30 cc) | Not a direct correlation | Prostate growth compressing the urethra |
| Symptom Expression | Highly individual; some have many symptoms, others have none | Depends on location and direction of growth | Urethral obstruction and irritation, causing bladder wall thickening |
| PSA Levels | Can be elevated due to increased prostate mass | Not directly related, but useful for monitoring | A larger gland produces more PSA, but high levels can also indicate cancer or prostatitis |
| Treatment Options | From lifestyle changes to medication or surgery | Based on symptom bothersomeness, not just size | A variety of therapies are available depending on symptom severity and personal preference |
Conclusion
For a man in his 70s, the concept of a 'normal' prostate size is best understood within the context of age-related growth. An average volume between 35 and 40 cc is common, but significant individual variation exists. Most importantly, prostate volume is less significant than the presence and bothersomeness of urinary symptoms. Men should focus on monitoring their symptoms and consulting a healthcare provider, rather than getting preoccupied with a specific number. Regular check-ups, which may include a DRE and PSA test, are vital for managing prostate health in this decade of life and beyond.
Visit Prostate Cancer Foundation for more information on managing prostate health
What are common symptoms of an enlarged prostate at 70?
- Frequent or urgent need to urinate.
- Waking up frequently at night to urinate (nocturia).
- A weak or slow urinary stream.
- A feeling of incomplete bladder emptying.
- Difficulty starting urination.
- A urinary stream that stops and starts (intermittency).
- Straining while urinating.
- Dribbling at the end of urination.
