Tachycardia refers to a fast-resting heart rate - usually at least 100 beats per minute. Tachycardia can be dangerous, depending on its underlying cause and on how hard the heart must work.
In general, the adult resting heart beats between 60 and 100 times per minute. When an individual has tachycardia, the upper and/or lower chambers of the heart beat significantly faster.
Our heart rates are controlled by electrical signals that are sent across the tissues of the heart. When the heart produces rapid electrical signals, tachycardia occurs.
When the heart beats too rapidly, it pumps less efficiently and blood flow to the rest of the body, including the heart itself, is reduced.
High blood pressure, or hypertension, occurs when your blood pressure increases to unhealthy levels. Your blood pressure measurement considers how quickly blood is passing through your veins and the amount of resistance the blood meets while it’s pumping.
Blood pressure is the force exerted by the blood against the walls of blood vessels, and the magnitude of this force depends on the cardiac output and the resistance of the blood vessels. Hypertension is classified as having blood pressure higher than 140 over 90 mmHg (millimeters of mercury). A diagnosis of hypertension may be made when one or both readings are high. This means the systolic reading (the pressure as the heart pumps blood around the body) is over 140 mmHg (millimeters of mercury) and/or the diastolic reading (as the heart relaxes and refills with blood) is over 90 mmHg.
Tobacco use is the "most important preventable cause of premature death in the United States. Cigarette smoking is so widespread and significant as a risk factor that the Surgeon General has called it 'the leading preventable cause of disease and deaths in the United States.'1
Smoking increases blood pressure, decreases exercise tolerance and increases the tendency for blood to clot.