As a nurse, our policy was to report blood pressures with diastolics (the bottom number - 120 in your case) greater than 90 to the physician. Anything over 90 for a diastolic blood pressure is too high. You should make an appointment with your doctor as soon as possible. The reason high blood pressure can be so bad it that it can cause a heart attack, stroke or aneurysm (leaking blood vessel). Heart attack as the heart has to work harder to pump blood out to the body against the extra pressure in the blood vessels. Stroke as the added pressure can cause hardening of the arteries which leads to blockage and weakening of the walls of small blood vessels in the brain, causing them to balloon and burst (this is an aneurysm). The risk of stroke is directly related to how high the blood pressure is. Have you been under stress? What have you been eating? What medications or herbal remedies have you been taking? Your doctor will need to know these things as stress can elevate you blood pressure, some foods can interact with any medications you might be taking. And certain medications in and of themself can increase your blood pressure. How often have you been checking your blood pressure and does high blood pressure or any type of heart disease run in your family? Hope this helps and Good luck!