Procedures On Blood Pressure & How Caffeine Affects It

Caffeine usage is a global phenomenon. In the United States, it is ubiquitous. Not only will you find it in beverages, it is also a common ingredient in medications such as pain relievers and respiratory medications. Because of its wide availability, you may have concerns about its effects on blood pressure, especially if you have an existing condition. Caffeine causes both negative and positive effects on your cardiovascular system. If you have high blood pressure, consult your doctor before beginning or increasing caffeine consumption.

Effects of Caffeine

Caffeine works on several systems of the body related to blood pressure. Chemically, it is similar to another substance in the body called adenosine. Caffeine binds with receptors for adenosine, blocking your natural response to sleepiness. Caffeine then stimulates the nervous system by simulating a fight-or-flight reaction. The purpose of the body's response in these situations is to increase your ability to handle stress. Caffeine stimulates the release of adrenaline or epinephrine to bring about these effects.

Cardiovascular Effects

The result of nervous system stimulation is an increase in blood pressure and constriction of blood vessels in the brain to enhance the body's ability to deliver oxygen and energy to cells. Your body works to ensure that a deficiency in either will not affect your ability to respond. It will also increase heart rate and breathing to ensure a continuous supply of oxygen. The constriction of blood vessels increases the pressure within them. A study by the University of Palermo in Italy, published in the May 2010 issue of "European Journal of Clinical Nutrition," found that ingestion of caffeine increased both systolic and diastolic blood pressure, the top and bottom number in your blood pressure reading. Systolic blood pressure reflects the pressure in blood vessels when the heart contracts. Diastolic is a measure of when blood vessels relax.

Duration

As long as caffeine remains in your system, detectable changes in blood pressure will exist. After absorption by the stomach and small intestine, it will reach its peak effects within 60 minutes. Absorption may be affected by what you have eaten and your own body chemistry. Some individuals are more sensitive to the effects of caffeine than others. Some may experience cardiac arrhythmias which may be visible on an electrocardiogram or EKG. You may feel as if your heart is racing. These effects are due to stimulation of the nervous system.

Cautions with Caffeine Usage

A person with high blood pressure is at risk for damage to blood vessels due to the stress on the circulatory system. If caffeine elevates your blood pressure, you may want to consider cutting back on your caffeine usage. The University of Palermo study found that caffeine decreased dilation of blood vessels that could have a negative effect on blood pressure, especially in individuals with uncontrolled hypertension. You can still enjoy the taste of coffee by drinking decaffeinated rather than caffeinated coffee.