Why does smoking make the heart work harder?

Smoking forces the heart to work harder through several physiological mechanisms triggered by the chemicals in tobacco smoke:

• Increased Heart Rate and Blood Pressure: Nicotine acts as a stimulant that triggers the release of epinephrine and norepinephrine, which directly increase heart rate and blood pressure, placing immediate stress on the heart.12
• Reduced Oxygen Transport: Carbon monoxide in cigarette smoke binds to hemoglobin in the blood more readily than oxygen does. This reduces the amount of oxygen available for transport to the body's tissues, forcing the heart to pump more vigorously to compensate for the oxygen deficit.34
• Constricted and Damaged Blood Vessels: Nicotine constricts blood vessels, while other toxins damage the lining of the arteries. This damage encourages the buildup of fat deposits, leading to arteriosclerosis, which narrows the arteries and reduces blood flow.15
• Thicker Blood: Smoking makes the blood thicker and stickier, which increases the effort required for the heart to circulate it effectively throughout the body.1

These combined factors place significant strain on the cardiovascular system, substantially increasing the risk of heart attack and stroke.14