Caffeine can cause a brief but dramatic rise in blood pressure, even if you don't have high blood pressure. It is not clear what causes this spike in blood pressure. The blood pressure response to caffeine varies from person to person. How does coffee raise blood pressure? Caffeine is a vasoconstrictor, meaning it reduces the size of blood vessels and can raise blood pressure. Caffeine exerts its effects by interacting with various receptors in the brain. Experts believe that other compounds in coffee, such as antioxidants, have a protective effect on blood vessels. Some people who regularly drink caffeinated beverages have higher average blood pressure than those who do not drink any beverages. Other people who regularly drink caffeinated beverages develop a tolerance to caffeine. As a result, caffeine has no long-term effect on their blood pressure. If you have high blood pressure, ask your doctor if you should limit or stop drinking caffeinated beverages. The U.S. Food and Drug Administration says that 400 milligrams of caffeine a day is generally safe for most people. However, if you are concerned about caffeine's effects on blood pressure, try limiting the amount of caffeine you drink to 200 milligrams per day, the amount typically found in two 8-ounce (237-milliliter) cups of brewed coffee. Keep in mind that the amount of caffeine in coffee, energy drinks and other beverages varies by brand and preparation. Also, if you have high blood pressure, avoid caffeine just before activities that naturally raise blood pressure, such as exercising, lifting weights or heavy physical labor. To see if caffeine can raise blood pressure, check your blood pressure before drinking a cup of coffee or other caffeinated beverage and again after 30-120 minutes. If your blood pressure rises by about 5 to 10 points, you may be sensitive to the blood pressure-raising effects of caffeine. If you plan to cut back on caffeine, do so gradually over several days to a week to avoid caffeine withdrawal headaches. When to stop drinking coffee In some people, drinking coffee causes insomnia, anxiety or tremors. Others may notice reflux and heartburn. Anyone experiencing these symptoms from coffee should avoid drinking it. According to the researchers, regular coffee drinkers may experience withdrawal symptoms such as headaches and lowered mood if they suddenly stop consuming coffee. Therefore, if they want to reduce its consumption, they should gradually reduce the number of cups. The authors of the review posted in JACC: Clinical Electrophysiology note that some physicians recommend avoiding coffee for people with atrial fibrillation or other conditions associated with irregular heart rhythms. However, they found that regular consumption of up to 300 milligrams of caffeine per day appears to be safe and may even protect against heart rhythm disorders. However, the researchers cautioned that if there is a clear link between arrhythmia episodes and caffeine, a person should not drink coffee.     [cool_tag_cloud on_single_display="local"]