Caffeine is found in medicine and various food items such as chocolate, coffee, tea, carbonated drinks and nutritional supplements. Caffeine is useful for many things. It is used as an aide for migraine or stress headaches to an effective energy booster. Caffeine can cause a high blood pressure reading, but usually this is a temporary side effect that can last several hours.
Increased Blood Pressure
Caffeine can cause a dramatic elevated blood pressure reading, even if you don't have high blood pressure or hypertension. According to Mayo Clinic physician, Sheldon Sheps, M.D., the caffeine found in 2 to 3 cups of coffee is enough to raise your blood pressure reading 3 to 14 points or mm Hg on the systolic or top number of your reading. Your diastolic readings or the bottom number can increase 4 to 13 mm Hg. The highest values could increase your blood pressure reading enough to classify you as having prehypertension, which is defined as having consistent blood pressure readings between 130 to 139 mm Hg for systolic and 80 to 89 mm Hg for diastolic, as stated by Columiba University's health information page Go Ask Alice.
Hypertension
If you have hypertension, caffeine still raises your blood pressure readings further. There is no evidence, according to Go Ask Alice, that caffeine causes hypertension or high blood pressure, but caffeine may raise blood pressure readings to dangerous levels temporarily. Limit your consumption of caffeine or eliminate it from your daily diet based on the advice your primary care physician provides you.
How Caffeine Works
Caffeine works on your central nervous system, which is the reason some people may experience caffeine jitters after drinking 1 to 2 cups of strong coffee. Adenosine is a hormone that regulates how wide your blood vessels widen. Caffeine blocks this hormone causing your blood vessels to narrow or constrict, leading to a temporary increase in your blood pressure, according to researchers Jason Daniels and colleagues with the University of California Davis. Blocking the relaxation effects of adenosine can lead to a cascade of hormonal changes, specifically increasing the release of adrenoline to increase cardiac output or cause your heart to beat faster and harder.
Effects of Caffeine
Some people are sensitive to the effects of caffeine. One cup of regularly brewed coffee can have up to 135 mg of caffeine. This may be enough caffeine to cause insomnia, restlessness, rapid heartbeat or tachycardia, jitters or nervousness, nausea or stomach irritation, sleeplessness and tachycardia or rapid heart beats in caffeine sensitive people. Dr. Sheps recommends limiting your caffeine intake to 200 mg per day which is found in 2 cups of coffee, but caffeine content can vary greatly in carbonated drinks and coffee. Exercise caution if you are sensitive to caffeine or have high blood pressure.
