Health hazards of smoking

Tobacco smoke is incredibly harmful to health. Replacing cigarettes with cigar, pipe or hookah won`t reduce health risks posed by smoking. According to American lung association, cigarettes contain about 600 ingredients, many of which are also in cigars and hookah. When they burn, they generate more than 7,000 chemicals many of which are toxic. At least 69 of them are carcinogenic, or known to cause cancer. The centers for disease control and prevention reports more than 4,80,000 deaths per year and note that smoking is most common preventable cause of death in the United States.

What are the effects of smoking on respiratory system?

Smoking is a crucial factor in causation and worsening of several respiratory illnesses. The major respiratory illnesses associated with smoking includes bronchial asthma, chronic obstructive pulmonary disease, emphysema, interstitial lung disease, lung fibrosis and lung cancer. Almost all types of pneumonias get worsened and are affected by smoking. 

A large study done in 2021 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8224924/) investigated association between long-term smoking and exercise capacity, gas exchange in lungs, lung volumes and flow rates. The arterial oxygen pressure and alveolar oxygen tension are shown reduce with increased smoking. The alveolar-arterial carbon dioxide gradient increased with >30 pack years smoking. The arterial oxygen saturation at rest and at maximum exercise declined as cigarette smoke exposure increased. The primary adverse effects of long-term cigarette exposure on pulmonary physiology are small airway narrowing and impairment in the alveolar gas diffusion capacity. An overall reduction in oxygen carrying capacity at cellular results in impaired metabolism, dysfunction and disease. 

How does smoking affect cardiovascular system?

Smoking is the leading cause of cardiovascular disease worldwide and also a preventable cause of mortality in individuals with an existing cardiovascular condition. Abstinence from smoking is largely recommended proceeding a cardiovascular event with various studies supporting the benefits to heart health post-cessation. 

The physiological changes that are known to precipitate into a cardiovascular event are 

1. Atherosclerosis – arteries become narrow and less flexible. It occurs when fat, cholesterol and other harmful substances in blood form plaque and build up in arterial walls narrowing arterial lumen. Chemicals in cigarette smoke cause the blood to thicken and form clots in heart arteries and veins. Blockage from a clot can lead to cardiac arrest and sudden death. 
2. Peripheral arterial disease – occur when blood vessels become narrower limiting the supply to arms, legs, hands and feet. In extreme cases reduced peripheral blood flow may lead to infection and/or gangrene. 
3. Stroke – Smoking impacts blood flow to the brain leading to permanent damage of neurons. Death from stroke is more likely among smokers than among former smokers or those who have never smoked. 
4. Abdominal aortic aneurysm – is a bulge or a weakness in the wall of abdominal aorta. The aorta is the main branch of the artery emerging from the heart carrying oxygenated blood to the whole body. Smoking is a known cause of damage to abdominal aorta. (https://www.cdc.gov/tobacco/sgr/50th-anniversary/pdfs/fs_smoking_cvd_508.pdf) 

How does smoking affect eyes?

Long-term smoking can affect vision and optic nerve leading to the following conditions – 

1. Glaucoma – intra-orbital pressure increases, leading to pressure on optic nerve which may lead to loss of vision. 
2. Cataract – may lead to cloudy vision.
3. Age related macular degeneration – which causes damage to a spot in the center of the retina and loss of central vision. 

What are the risks of smoking on pregnancy?

Smoking reduces fertility, thereby chances of pregnancy. In men, sperm damage is caused by high levels of carcinogens and mutagenic substances in cigarette. Heavy metals like lead and cadmium are known to damage sperms. Studies have also shown that smoking leads to DNA damage in sperms which results in reduced male fertility and increase in miscarriages. 

Smoking has also been associated with erectile dysfunction that contributes to difficulty in conceiving. In chain smokers, the sperm count, concentration, motility and shape are adversely affected (https://health.clevelandclinic.org/how-stopping-smoking-boosts-your-fertility-naturally). 

In females, toxic levels of smoke carcinogens are known to harm eggs and premature aging of ovaries. Few studies have found evidence of tube blockage and increased risk of ectopic pregnancy. There is increased risk of miscarriage due to damaged eggs, damage to developing fetus, or unfavorable changes to the uterus lining making healthy implantation less likely. 

Smoking during pregnancy is known to increase the risks of birth defects such as those of cardiovascular system, limbs (arms/legs fail to grow fully or missing completely), cleft palate, skull malformations, facial and eye deformations, gastrointestinal or anal defects, undescended testes and other congenital defects. Several issues during and after labor are also associated with smoking such as early delivery, low birth weight, still birth and sudden infant death syndrome. 

Smoking and Diabetes

A smoker is 30-40% more likely to get type 2 diabetes compared with a non-smoker. If a diabetic person starts smoking, sugar control becomes more difficult with increased risk of having more adverse effects on health. 

How can smoking lead to diabetes?

• Insulin resistance – Presence of nicotine increases insulin resistance, hence makes it harder for the body to use sugar. As a result, blood sugar levels are increased. 
• Inflammation – Several toxic chemicals and heavy metals present in smoke are pro-inflammatory making it difficult for the body to heal wounds or fight infections. 
• Increased midsection fat – smoking may lead to increased belly fat, making the individual more prone to having type 2 diabetes. 

Few studies show that smoking can raise triglycerides which also may contribute to increased risks of atherosclerosis and small blood vessel damage. 

How does smoking make diabetes worse?

The combination of diabetes and smoking has direct and significant implications on the circulatory system. Increase in insulin resistance, blood sugar concentration with added toxins from smoking leads to plaques and clot formation and blockage of small and large blood vessels. These pathophysiological changes can occur in various blood vessels of body and can result in 

How can one quit smoking? 

If quitting on your own is difficult, seeking help from healthcare team can offer various options. A few maybe – 

• Nicotine patches/replacement therapy
• Mindfulness training for smoking cessation
• Antidepressants
• Try exercising when there is an urge
• Learn relaxation techniques that work for you
• Chew on sugar-free candy or gummies
• Counseling 

(https://www.mayoclinic.org/healthy-lifestyle/quit-smoking/in-depth/nicotine-craving/art-20045454)