Why it changes
Blood pressure naturally rises and falls over 24 hours. It usually goes up after you wake and is lower while you sleep. Activity, stress, caffeine, meals and medicine timing all move it too.
Why measure at both times
Morning and evening readings together give a fuller picture of your usual blood pressure, and many doctors ask for both.
Morning readings
Within about an hour of waking, after using the bathroom, before breakfast, caffeine or exercise. Ask your doctor whether to measure before or after taking your blood pressure medicine.
Evening readings
Before dinner or before bed, after resting quietly for 5 minutes.
Every time
Same arm, same position, 2–3 readings a minute apart. Follow the routine on our How to take your blood pressure at home page.
Look at averages, not one number
A single high or low reading is common. Your average over days and weeks is what matters, and what your doctor will want to see.
How FourNumbers helps
The 7-day BP check reminds you morning and evening and shows both averages.
Source: American Heart Association.