A lot of people enjoy their coffee first thing in the morning, but this can have a side effect besides wakening us up! It turns out that coffee affects the region of the brain that controls the anxiety and this can often stress people out.
It was proven that if a coffee is taken before 1P.M, the stress and anxiety effects can last till late evening. This could be high blood pressure, nervousness and restlessness and usually they affect the sleep.
During the studying process it was made an experiment with a group of volunteers. On the first day they drunk a coffee with a normal amount of caffeine in it and next day they had a placebo. The participants were more stressed when taking the caffeine and there was registered a little higher blood pressure and the produced stress hormone (norepinephrine) was about 30 percent more comparatively with the second day.
So, consider that when you are consuming a cup of coffee in the morning, it will need about 4 hours to get rid of half the portion of caffeine you took, and after 8 hours not all of it would be out of your blood.
Coffee is pleasant in the morning, but if you are stress related or have any type of heart disease - decrease the amount of coffee you drink, or even give up on it.