How much will it help to lower blood pressure if u quit smoking?

Blood Pressure: Quitting smoking will have many beneficial effects including the likely possibility of lowering blood pressure. Many factors effect blood pressure including heredity. Consult your doctor if you want to get a baseline on your current medical condition and how it will be effected with better health habits. My best.

A LOT!: Smoking is an independent cause of high blood pressure. More importantly, smoking itself causes atherosclerosis which increases your risk of heart attack and stroke. Plus buerger's disease (google it), cancer of the head/neck/lung/bladder, emphysema, etc. But yes, if you quit, your blood pressure will decrease which by itself will reduce your risk for many diseases.

Smoking cessation: Stopping smoking will help virtually everything including slight lowering of high blood pressure. There is nothing good about smoking except to help the tobacco industry.