What are the diseases caused by smoking? A comprehensive health guide

October 1, 2025 •

3 min read

According to the Centers for Disease Control and Prevention (CDC), cigarette smoking is responsible for more than 480,000 deaths per year in the United States, raising the critical public health question: what are the diseases caused by smoking?. Smoking damages nearly every organ in the body, leading to a host of serious and often fatal illnesses.

Quick Summary

Smoking is a primary cause of cancer, cardiovascular disease, and chronic lung conditions like COPD and emphysema. The toxic chemicals in tobacco smoke damage cells, weaken the immune system, and harm nearly every organ. Health risks are also elevated for individuals exposed to secondhand smoke, including non-smokers and children.

Key Points

Extensive Cancer Risk: Smoking causes nearly 90% of lung cancer deaths and is a direct cause of cancers in the mouth, throat, esophagus, bladder, and several other organs.
Major Cardiovascular Damage: It significantly increases the risk of heart disease, heart attack, stroke, and peripheral artery disease by damaging blood vessels and creating atherosclerosis.
Severe Respiratory Conditions: Smoking is the primary cause of Chronic Obstructive Pulmonary Disease (COPD), which includes emphysema and chronic bronchitis, leading to irreversible lung damage.
Systemic Impact: Beyond the major systems, smoking contributes to type 2 diabetes, reduced fertility, immune system problems, and vision loss from conditions like macular degeneration.
Secondhand Smoke is Harmful: Even non-smokers exposed to secondhand smoke face increased risks of heart disease and lung cancer, with children being particularly vulnerable to respiratory issues.
Quitting Yields Major Benefits: Quitting smoking has immediate and long-term health benefits, significantly reducing the risk of developing and dying from smoking-related diseases.

The toxic cocktail in tobacco smoke

Tobacco smoke contains over 7,000 chemicals, at least 70 of which are known to cause cancer. These include tar, which coats the lungs; carbon monoxide, which reduces oxygen in the blood; oxidizing chemicals that damage the heart and blood vessels; and heavy metals and radioactive compounds. These harmful substances enter the bloodstream and cause widespread damage throughout the body.

Cancers caused by smoking

Smoking is a leading cause of preventable cancer deaths globally and is strongly linked to numerous types of cancer. The most significant risk is for lung cancer, with nearly 90% of deaths attributed to smoking or secondhand smoke. Smoking also increases the risk of cancers of the mouth, throat, esophagus, larynx, bladder, kidney, ureter, pancreas, stomach, liver, colon, rectum, and cervix, as well as acute myeloid leukemia (AML).

Cardiovascular diseases

Smoking is a major factor in heart disease and stroke by damaging blood vessels. It contributes to coronary heart disease by narrowing heart blood vessels, increases the risk of heart attacks, and promotes atherosclerosis (plaque buildup in arteries). Smoking also doubles the risk of stroke and is the main cause of aortic aneurysms. Furthermore, it can lead to peripheral artery disease (PAD), restricting blood flow to the limbs.

Respiratory illnesses

Smoking causes significant damage to the respiratory system, leading to various severe conditions. It is the primary cause of Chronic Obstructive Pulmonary Disease (COPD), which includes emphysema (damaging air sacs) and chronic bronchitis (airway inflammation). Smoking doesn't cause asthma but can trigger attacks and worsen symptoms. It also weakens lung defenses, increasing susceptibility to infections like pneumonia, influenza, and tuberculosis.

Other systemic health consequences

The negative effects of smoking extend throughout the body. Smokers have a 30-40% higher chance of developing Type 2 diabetes and experience worsened complications if they already have it. Smoking harms reproductive health, causing erectile dysfunction in men and reducing fertility and increasing pregnancy risks in women. It also increases the risk of vision loss from macular degeneration and cataracts, weakens the immune system, and causes oral health issues like gum disease and tooth loss.

The contrast: Quitting vs. Continuing to smoke

Quitting smoking offers significant health benefits, even for long-term smokers. The table below illustrates the difference in health risks between those who continue to smoke and those who quit.


Health Outcome	Impact for a Continuing Smoker	Impact for a Quitter
Heart Disease	Significantly higher risk of heart attack, stroke, and cardiovascular damage.	Risk is halved within one year of quitting and continues to drop over time.
Lung Cancer	Risk is 25 times higher than a non-smoker.	After 10-15 years, the risk of lung cancer drops by half.
Oral Cancer	High risk for cancers of the mouth, throat, and larynx.	After 5-10 years, the risk of oral and throat cancers drops by half.
COPD Symptoms	Continues progressive lung damage, leading to worsened breathlessness and coughing.	The rate of decline in lung function slows to that of a non-smoker.
Circulation	Reduced blood flow to extremities, increasing risk of PAD and amputation.	Blood flow improves, helping to reverse damage and reduce risk.

The dangers of secondhand smoke

Secondhand smoke, containing many of the same harmful chemicals as directly inhaled smoke, is a known carcinogen and poses serious health risks to non-smokers. Exposure increases the risk of heart disease by 25–30% and lung cancer by 20–30%. Children are particularly vulnerable, with increased risks of respiratory infections, ear infections, severe asthma, and Sudden Infant Death Syndrome (SIDS).

Conclusion

Understanding what are the diseases caused by smoking reveals the extensive and serious health consequences of tobacco use. Smoking is a direct cause of numerous life-threatening conditions, including various cancers, heart disease, and chronic lung diseases. Quitting smoking is the most crucial step to improving health, offering benefits that start almost immediately and reduce the risk of many smoking-related illnesses over time. Resources like counseling and medication are available through organizations such as the National Cancer Institute (NCI) and the Centers for Disease Control and Prevention (CDC) for those who want to quit.

Visit the CDC's website for more resources on quitting smoking.

Frequently Asked Questions

Lung cancer is the most common cancer caused by smoking. It is responsible for nearly 9 out of 10 lung cancer deaths, and the risk increases with the duration and amount of smoking.

Smoking damages the heart and blood vessels by promoting atherosclerosis (buildup of plaque in arteries), increasing blood pressure, and raising the risk of blood clots. This can lead to coronary heart disease, heart attacks, strokes, and aneurysms.

Yes, secondhand smoke is a proven cause of heart disease and lung cancer in non-smokers. It is also particularly harmful to children, increasing their risk of respiratory infections, ear infections, and SIDS.

Besides lung cancer, smoking causes Chronic Obstructive Pulmonary Disease (COPD), which includes emphysema and chronic bronchitis. It also worsens asthma and increases susceptibility to respiratory infections like pneumonia.

Yes, smoking can cause Type 2 diabetes. Smokers are 30-40% more likely to develop the disease than non-smokers, and smoking can worsen related health complications for those who already have diabetes.

In men, smoking is a known cause of erectile dysfunction. In women, it can lead to reduced fertility and an earlier onset of menopause. For pregnant women, smoking increases the risk of miscarriage, premature birth, and low birth weight.

Health benefits start almost immediately after quitting. Within one year, the risk of heart disease is halved compared to a continuing smoker. Other risks, including those for various cancers, continue to decrease over time.