What Affects PSA Results?

Identification

• Normal PSA levels are low in males. A high PSA level, determined by a laboratory test result of higher than 4.0 nanograms of PSA per milliliter of blood, warrants further evaluation.
  
  

Potential

• Elevated PSA results can be potentially due to prostate inflammation, infection or benign enlargement with aging.
  
  

Time Frame

• PSA blood testing should be performed before or six weeks after other prostate testing procedures like direct rectal exam (DRE) and biopsy, since the stimulation of the prostate by these procedures may cause an elevated PSA result.
  
  

Treatments

• Large doses of chemotherapeutic drugs such as cyclophosphamide and methotrexate may cause a decrease or increase in PSA levels.
  
  

Considerations

• Rigorous physical activities that involve the prostate, such as biking, may cause a temporary rise of PSA levels and should be avoided before PSA testing.
  
  

Expert Insight

• According to the National Cancer Institute, prostate cancer was diagnosed in men with normal PSA levels. The PSA test alone does not give doctors enough information to diagnose or rule out prostate cancer, and interpretation of PSA results should be in the light of findings from other tests as well as other risk factors.