What are the effects of coffee on your blood pressure?
I am just learning that I may have borderline high blood pressure and I am a big coffee drinker. What are the effects of coffee on your blood pressure?
Caffeine is a stimulant. Caffeine speeds up the heart rate and increases blood pressure soon after consumption. It seems that the effects of caffeine on blood pressure are related to the baseline blood pressure. For example, those with high blood pressure would likely experience a greater increase than those with normal blood pressure from the same cup of coffee.
An interesting effect of caffeine I see in some patients is the effect on daytime alertness. It is well known that caffeine helps prevent fatigue and sleep. The cycle some patients fall into is one where they consume caffeine several times per day when they feel tired or sleepy. Later that night they have difficulty falling or staying asleep. The next morning they awake feeling drowsy which persists until the first cup of coffee, and so on–a viscous cycle begins. This cycle of fatigue self-medicated with caffeine stresses the body. This, in turn, can elevate blood pressure.
I advise my patients with high blood pressure to moderate their caffeine intake. Two cups of caffeinated beverages (soda, coffee, tea) per day is usually the maximum one should have. If possible, no caffeine should be had for at least four hours prior to bed.
Important: We hope you find this general medical and health information useful, but this Q&A is meant to support not replace the professional medical advice you receive from your doctor. For all personal medical and health matters, including decisions about diagnoses, medications and other treatment options, you should always consult your doctor. See full Disclaimer.
Dr. Glenn Gandelman is board certified in internal medicine, cardiology, echocardiography, and nuclear medicine. He specializes in prevention, diagnosis and treatment of cardiovascular disease. He wrote for HealthCentral as a health professional for Heart Disease and High Blood Pressure.