However, when you want to compare a Boolean variable with the literal Boolean value true or false, it is not necessary to do an explicit comparison, because the result of evaluating a Boolean value is that Boolean value. For example, the expressions
The nicotine in cigarette smoke is a big part of the problem. It raises your blood pressure and heart rate, narrows your arteries and hardens their walls, and makes your blood more likely to clot. It stresses your heart and sets you up for a heart attack or stroke. Know Your Blood Pressure Numbers.
1 There is inconsistent evidence about the effects of green tea on blood pressure. 2  Some research shows that drinking green tea regularly can lower the risk of developing high blood pressure. 3  However, other research shows that it has no effect on blood pressure in people with or without high blood pressure.