Does caffeine raise blood pressure?

Originally Published: September 7, 2001 - Last Updated / Reviewed On: July 27, 2012
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Dear Alice,

Does caffeine raise your blood pressure?

Dear Reader,

In people with normal blood pressure, it appears that caffeine may cause a temporary increase in blood pressure. This is becasue caffeine is a vasoconstrictor — that is, it can narrow blood vessels. Some folks develop a tolerance to caffeine, and it no longer has this effect. But above all, it is important to know that there is no evidence that caffeine can cause high blood pressure, also known as hypertension.

For individuals with high-normal blood pressure or diagnosed hypertension, however, caffeine seems to raise their levels to a much greater degree than those with normal readings. Therefore, a person who has hypertension should try to avoid caffeine.

 

For reference, classification of blood pressure is as follows:

Category Systolic in mm Hg (top #)   Diastolic in mm Hg (bottom#)
Normal <120 and <80
Prehypertension 120-139 or 80-89
Stage 1 HBP 140-159 or 90-99
Stage 2 HBP >160 or >100

For your average joe, Because of the temporary rise in blood pressure triggered by caffeine in some people, it's probably a good idea to refrain from a cup of joe just before a blood pressure test. It's also important to realize that chocolate, soda, and energy drinks all have various amounts of caffeine. 

For those who cannot give up good ol' java, decaffeinated coffee may serve as a suitable substitute, with a typical caffeine content of about 5 mg per 8 oz. cup (versus around 135 mg of caffeine for the regular brew). For those seeking an alternative beverage altogether, hot cocoa is a choice that also contains approximately 5 mg of caffeine per 8 oz. mug, plus it contributes calcium and the oh-so-sought-after (for some) taste of chocolate! There are also herbal teas, which contain no caffeine and are available in a variety of flavors. More options can be found at your local health foods store, including non-caffeinated herbal or grain beverages.
Alice