A blood pressure reading of 124/77 mmHg is generally considered to be within the prehypertension range. The top number (systolic) is 124, and the bottom number (diastolic) is 77. While not yet classified as high blood pressure (hypertension), it's a good idea to monitor your blood pressure regularly and make lifestyle changes such as diet and exercise to help lower it. Consult your doctor for personalized advice.