How to Get an Accurate Blood Pressure Reading

Blood pressure measures the force of blood against the walls of your arteries as your heart pumps. The top number (systolic) indicates the maximum pressure the heart exerts while beating. The bottom number (diastolic) is the pressure in the arteries between beats. Physicians consider a difference of more than 40 mm Hg between the two abnormal (this is called pulse pressure).

Factors That Affect Blood Pressure Readings

Stress and anxiety. A stressful situation can cause a dramatic, temporary spike in your blood pressure. A single incident is not cause for alarm; however, if this happens frequently, it can damage your blood vessels, heart, and kidneys. Stress can also cause you to engage in behavior that may further damage your heart, such as smoking or drinking.

The season. Blood pressure tends to be higher in the winter because low temperatures cause your blood vessels to narrow so you need more force to push the blood through your body.  

Alcohol. Drinking three or more drinks at once may cause a temporary uptick in blood pressure. Over time, excessive drinking may cause a long-term increase.

Daily patterns. Your blood pressure is usually lower while you sleep and shortly after waking, then rises throughout the day, peaking in mid-afternoon.

Caffeine. Coffee and other caffeinated beverages can also cause a short but dramatic increase in your blood pressure.

Measurement errors. Your blood pressure measuring device may not be working properly, or you (or your healthcare provider) may not take your blood pressure correctly. Even something as innocuous as a tight belt can affect your reading.

If you experience a high blood pressure reading, try again later. Take a walk or practice slow, deep breathing so you're calm before you try again. Drinking water and avoiding certain foods, such as dark chocolate, garlic, and bananas beforehand may help ensure an accurate reading. If you continue to get high readings and you've ruled out outside factors as possible culprits, then see your physician. You can make simple lifestyle changes to lower your blood pressure, or if appropriate, seek medical care.




Sheldon G. Sheps, M.D. "High blood pressure." Mayo Clinic. Web. 26 August 2011.

Mayo Clinic. "High blood pressure." Web.

Ray, Claiborne. "Pressure Problems." New York Times. Web. 13 December 2010.