Q: What is a normal blood pressure for an adult over 18 years?
A: 120/80
Stage 1 Hypertension > 140/90
Stage 2 Hypertension > 160/100

Why is it important for my dentist to check my blood pressure? What does that have to do with my teeth?
Checking blood pressure at the dental office is a great way to screen for high blood pressures and make an early referral to your doctor if an abnormal blood pressure is encountered. High blood pressure is a risk factor for heart disease. 30% of people with hypertension are unaware
If you know you have high blood pressure, be sure to inform your dentist. Some local anaesthetic agents (dental freezing) contain epinephrine. Epinephrine is also found in your body normally and can increase your blood pressure. This is especially possible in people with an already elevated blood pressure. If your dentist is aware of your high blood pressure, they can be sure to use just the right amount of local anaesthetic to make sure you receive the best care.