What would be a normal blood pressure for 15 year old boy who stands 59 and weighs roughly 240 pounds? what would be considered to high or to low

Depends on details: Numbers are just numbers, with little meaning unless we have the entire picture. So, a tall teen in a doctor's office usually is between 100/60 and 125/75. If near or over the upper end, then careful repeat measurements are made while keeping him happy and smiling. The cuff has to be the right size (using a smaller cuff gives a bigger number). Numbers are tracked over time, to plan care.

BP chart: Serial measurements may be performed at your PCP's office and there are charts available based on gender and age of the child. The elevation in BMI is important since it is a risk factor for hypertension. A comprehensive weight reduction program is suggested. Avoid trans fats, excessive sugar and high calorie foods, exercise daily as tolerated and approved by your PCP.