Caffeine is a stimulant and can increase your heart rate and your blood pressure. For most people this stimulation is neither dangerous nor does it lead to heart disease. However, if you’ve had a heart attack or have high blood pressure, I would opt for decaf coffee and drinks.
The caffeine in coffee is unquestionably addicting. People who drink a lot of coffee find that when they go without coffee for more than about twelve hours they develop withdrawal symptoms like headache, nervousness, and a cranky disposition.
Many experts consider your level of caffeine intake excessive. However, there is no evidence that up to four cups of coffee a day will produce any harmful effects on your health. If you have problems with stomach irritation, insomnia, headaches, or diarrhea, I would listen to my body and cut back on my caffeine consumption.
Remember that caffeine is in a lot of drinks. The average cup of coffee contains about 115 mg of caffeine which is about what a cola drink contains. Tea is not caffeine free, either: one cup has about 40mg. When you add up your caffeine consumption, it may be far higher than the five cups you drink each day.