How does smoking affect the heart?

Smoking damages the heart by increasing the risk of heart disease and stroke, and by affecting blood pressure and cholesterol.

Smoking is a major risk factor for cardiovascular diseases, which include heart disease and stroke. The chemicals in tobacco smoke harm your blood cells and damage the function of your heart. This damage increases your risk of atherosclerosis, a disease in which a waxy substance called plaque builds up in the arteries. Over time, this buildup narrows the arteries, making it harder for blood to flow through and causing the heart to work harder, which can lead to heart disease.

Nicotine, the addictive substance in cigarettes, raises your blood pressure and heart rate, making your heart work harder. It also tightens your arteries, which can restrict the flow of blood to your heart, brain, and other organs. This can cause a heart attack or stroke. Moreover, smoking lowers the levels of high-density lipoprotein (HDL), or 'good' cholesterol, and raises the levels of low-density lipoprotein (LDL), or 'bad' cholesterol. This imbalance can lead to cholesterol deposits in your arteries, further increasing your risk of heart disease.

Smoking also makes blood more likely to clot, which can block blood flow to the heart or brain, leading to a heart attack or stroke. Carbon monoxide from inhaled cigarette smoke replaces some of the oxygen in your blood, forcing your heart to work harder to supply enough oxygen to your body and organs.

In addition, smoking damages the lining of your arteries, leading to a buildup of fatty material (atheroma) which narrows the artery. This can cause angina, a heart attack, or a stroke. The chemicals in tobacco can also damage your heart muscle, making it less able to pump blood effectively, which can lead to heart failure.

In conclusion, smoking has a profound and detrimental effect on the heart, increasing the risk of various cardiovascular diseases and conditions.