Smoking is one of the leading causes of preventable death worldwide. It harms nearly every organ in the body, contributing to a wide range of diseases and significantly reducing life expectancy. The chemicals in tobacco smoke, including nicotine, tar, carbon monoxide, and thousands of other harmful substances, cause immediate and long-term damage.

1.Increased Risk of Cancer

Smoking is a major cause of various types of cancer. Tobacco smoke contains over 70 known carcinogens, which directly damage cells and lead to cancer development.

Lung Cancer: Smoking is responsible for approximately 70% of lung cancer cases, making it the most common cause of this deadly disease. Smokers are about 15–30 times more likely to develop lung cancer compared to non-smokers.
Other Cancers: Smoking also increases the risk of cancers of the mouth, throat, oesophagus, bladder, pancreas, stomach, and kidneys.

Read more: Cancer Research UK - Smoking and Cancer

2. Cardiovascular Disease

Smoking damages the heart and blood vessels, significantly increasing the risk of cardiovascular diseases (CVDs). This includes:
Coronary Heart Disease (CHD): Smoking causes atherosclerosis (narrowing of the arteries) by promoting the build-up of fatty deposits. This can lead to heart attacks and strokes.
Stroke: Smokers are at a much higher risk of stroke, as smoking reduces blood flow and can cause blood clots.
Peripheral Arterial Disease (PAD): Smoking can damage blood vessels in the legs and arms, leading to restricted blood flow and, in severe cases, gangrene.

Learn more: British Heart Foundation - Smoking and Your Heart

3. Respiratory Diseases

The harmful chemicals in tobacco smoke damage the lungs and airways, leading to chronic respiratory conditions:
Chronic Obstructive Pulmonary Disease (COPD): Smoking is the leading cause of COPD, which includes conditions like chronic bronchitis and emphysema. These diseases cause permanent lung damage and result in breathing difficulties.
Chronic Bronchitis: Regular smoking irritates the airways, leading to chronic inflammation, excessive mucus production, and persistent coughing.
Emphysema: Smoking destroys the tiny air sacs in the lungs (alveoli), making it difficult to breathe and leading to irreversible damage.

Read more: NHS - Smoking and Respiratory Disease

4. Weakened Immune System
Smoking suppresses the immune system, making it harder for the body to fight infections and recover from illnesses. Smokers are more prone to respiratory infections like pneumonia and the flu. Additionally, smoking slows wound healing and increases the risk of complications following surgery.

5. Reproductive and Pregnancy Complications

Fertility Problems: Smoking affects both male and female fertility. In women, it can damage the ovaries, leading to earlier menopause. In men, it can reduce sperm count and motility.

Pregnancy Complications: Smoking during pregnancy increases the risk of miscarriage, stillbirth, preterm birth, and low birth weight. It can also lead to developmental problems in children.

Learn more: NHS - Smoking and Pregnancy

6. Impact on Mental Health

Although many smokers believe that smoking helps them relax, nicotine is a highly addictive substance that can exacerbate anxiety and depression over time. The withdrawal symptoms from nicotine can also contribute to stress and irritability.

7. Second-hand Smoke

Second-hand smoke (also known as passive smoking) exposes non-smokers, including children and pets, to the same harmful chemicals in tobacco smoke. This can lead to:

Increased risk of lung cancer and heart disease in non-smokers.
Respiratory issues in children, such as asthma, bronchitis, and ear infections.

Higher risk of sudden infant death syndrome (SIDS) in babies exposed to second-hand smoke.

Read more: NHS - Dangers of Second-hand Smoke

8. Life Expectancy and Overall Health
Smoking significantly reduces life expectancy. On average, smokers die 10 years earlier than non-smokers. It not only increases the risk of premature death but also reduces quality of life by contributing to chronic illnesses and disability.

Conclusion

Smoking has devastating effects on nearly every organ of the body, increasing the risk of cancers, cardiovascular diseases, respiratory conditions, and more. Quitting smoking at any stage can significantly improve health outcomes and reduce the risk of these conditions.

Further Reading and References:
NHS: NHS - Why Quit Smoking?
World Health Organization (WHO): WHO - Tobacco
Centres for Disease Control and Prevention (CDC): CDC - Health Effects of Smoking
These resources provide in-depth information about the effects of smoking and the benefits of quitting.

Dr Geranmayeh