In fact, of all the things that increase your risk of heart disease, smoking tobacco is the most dangerous risk factor that is under your direct control.
The Link Between Smoking and Heart Disease Risk
Smoking multiplies the odds of heart disease in everyone, and it is especially dangerous for women. The risk of having a heart attack is six times higher in women smokers, and three times higher in men smokers, than in people who never smoked.
Worldwide, smoking is thought to account for almost 36% of first heart attacks.
Not only does smoking cause heart disease, but once you develop heart disease, if you keep smoking your heart problems will likely become much worse, much faster. And you will have a much higher chance of dying from your heart disease.
People who keep smoking after a heart attack have a much higher risk of subsequent heart attacks. People who smoke after bypass surgery or after receiving a stent have a much higher incidence of developing new blockages in the treated artery. And smokers with coronary artery disease (CAD) or heart failure have a substantially higher risk of premature death than non-smokers with these conditions.
How Smoking Causes Heart Disease
The major cardiovascular consequence of smoking is that it greatly accelerates the development of atherosclerosis (hardening of the arteries). Smoking worsens atherosclerosis in several ways:
Smoking increases LDL cholesterol (bad cholesterol) blood levels and reduces HDL cholesterol (good cholesterol) blood levels. Tobacco products contain numerous toxic chemicals that can irritate the blood vessel walls—increasing inflammation, and damaging and “stiffening” the vessel walls. Smoking increases adrenaline levels, which in turn raises blood pressure and cardiac stress, causing constriction of blood vessels. Smoking substantially increases the tendency of blood to form clots within blood vessels, thus increasing the risk of acute coronary syndrome (ACS)—the condition that produces heart attacks and unstable angina.
In addition to accelerating atherosclerosis, smoking tobacco has other damaging effects on the cardiovascular system:
The nicotine in tobacco contributes to the increase in heart rate and blood pressure seen after smoking a cigarette. Smoking increases serum homocysteine levels, which is thought to cause vascular injury. Smoking increases carbon monoxide blood levels, reducing the blood’s capacity to deliver oxygen to the tissues.
Furthermore, smoking not only affects the person who has decided to be a smoker; it also affects family, friends, and loved ones who breathe secondhand smoke. While the data showing that secondhand smoke increases the risk of cardiovascular disease is not as firmly established as it is for smokers themselves, most studies agree that it does increase the risk in innocent bystanders.
Acute Effects of Smoking a Cigarette
Several of the harmful effects produced by smoking happen right away. Changes in heart rate and blood pressure, negative clotting effects, and some chemical changes within blood vessels can occur immediately after you light up. The acute elevation in cardiovascular risk after smoking a cigarette persists for up to 72 hours.
That’s the bad news. The good news is: This means that even a chronic smoker can substantially reduce their cardiovascular risk within a few days of stopping.
Cardiac Benefits of Smoking Cessation
Just as smoking tobacco accelerates atherosclerosis, if you quit smoking you can slow the progression of atherosclerosis. Furthermore, smoking cessation actually substantially improves the overall function of your blood vessels. As mentioned, the risk of developing cardiovascular disease drops quickly after you quit smoking—and continues dropping, the longer you remain tobacco-free.
After an episode of ACS, smokers who quit immediately have a much lower risk of dying in the near future, as compared to smokers who do not quit. Quitting also substantially reduces your risk of having another episode of ACS.
Your risk of stroke is also substantially reduced over time after you quit smoking.
The benefits of smoking cessation are seen in both men and women, and in all age groups.
Why You Should Quit Smoking Right Now
Once again, it cannot be over-emphasized that many of the adverse effects of smoking occur acutely—right after you light up. And your chances of having an acute heart attack will actually diminish within a few days after your last smoke.
So, not only should you quit smoking, you should quit smoking as soon as you possibly can.
A Word From Verywell
Smoking is the leading preventable cause of premature heart disease and stroke. The benefits of smoking cessation are strongly established, and those benefits begin to take place within a day or two of your last cigarette.
