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One of the more serious possible conditions from long-term cigarette smoking is heart disease. That's a statement we hear often in discussions of smoking. But what does it really mean? What is heart disease, and how does smoking cause it?
In this context, the phrase 'heart disease' usually refers to coronary artery disease. That's a condition in which a major blood vessel that leaves the heart carrying oxygen-rich blood becomes constricted. That increases the odds of a clot or closure that causes a heart attack. That's why it's sometimes called 'having a coronary'.
Long term, heavy smoking greatly increases the odds of that happening for several reasons.
Carbon monoxide is present in cigarette smoke. It binds with hemoglobin, the molecule in red blood cells that helps transport oxygen throughout the body, including the heart. Reducing the oxygen to the heart ups the odds of heart disease.
Nicotine also reduces the amount of oxygen in the blood, while contributing to other conditions that are potentially harmful. It increases blood clotting, which can have a direct effect on the risk of heart attack, as we saw above.
But even more subtle, yet still dangerous, effects are produced by nicotine. One of the most serious, long term, is that it encourages the growth of fatty deposits on the arteries, constricting blood flow and hardening the blood vessel.
One of the ways smoking carries out that damage is by decreasing the amount of HDL (high density lipoprotein), the 'good' type of cholesterol. That encourages the growth of those fatty deposits. That condition is called atherosclerosis and it's a major factor in heart attack risk.
Reducing the diameter of the artery increases blood pressure. That makes it more likely that any weakness present in the artery wall, something termed an aneurysm, will lead to a rupture. That leads to oxygen starvation to the brain, resulting in a stroke. That's why one so often sees 'raises the risk of heart disease and stroke' discussed in the same sentence.
Hardening an artery makes it less able to withstand the normal stresses and strains of its function, as well. Remember, a blood vessel is both similar to a hose and different in important ways.
Like a hose, it carries fluid and can only do so when there are no holes. At the same time, unlike most hoses, it's 'on' all the time. Any stoppage of blood flow, however temporary, causes immediate health problems. Tissues need a continual supply of blood or they die very quickly.
There's also an overall effect from cigarette smoking that contributes to the risk of heart disease. Smoking causes several physical effects that reduce health. Reduced oxygen, shortness of breath and other effects make exercise more difficult and unpleasant. That, and lifestyle choices often associated with smoking, reduce overall fitness.
That lack of exercise, and the increased weight gain and body fat percentage that tends to accompany it, increases further the chances of heart disease and heart attack. The body is unable to withstand strains that might otherwise be minor. It is less able to withstand the serious biological shock that occurs when a heart attack finally happens. That ups the odds that the attack will be fatal.
Long-term, one-pack-a-day smokers have 2-4 times the chance of developing coronary heart disease than do non-smokers. Quitting today improves your odds immediately. Within 3 months circulation improves. After a year, the odds are half that of a smoker. After 5-15 years, the odds are that of someone who has never smoked. Don't think it's too late. Start today on a program to quit smoking.
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