A blood pressure reading of 138/90 mmHg is generally considered to be in the stage 1 hypertension range. While not drastically high, it's important to address this level of blood pressure to prevent potential health complications. Factors like age, overall health, and other existing conditions play a role in determining the best course of action. Consult with a healthcare professional for a proper diagnosis and personalized recommendations, which may include lifestyle changes like diet and exercise, or potentially medication.