Smoking cigarettes exposes the body to over 7,000 chemicals. At least 70 of these are known to cause cancer, and many more are defined as poisonous. The health effects of inhaling these toxic substances are systemic – smoking affects all parts of the body, both long-term and immediately after lighting up.
Inhaling smoke brings toxic substances into the body through the respiratory system. The tissues in the throat, windpipe and lungs are quite robust but aren't able to defend themselves against these toxic attacks for long. The toxins found in tobacco smoke damage the cells in the respiratory system. The body then mounts an inflammatory response and begins healing the damage. Both the inflammation and built-up scar tissue can cause obstructions in the respiratory system, making it harder for air to flow, or for gas exchange to occur in the lungs.
Chronic Obstructive Pulmonary Disease
Chronic Obstructive Pulmonary Disease or COPD occurs when the body mounts an inflammatory response against the toxins inhaled while smoking. There are two conditions that fall under the COPD umbrella. Some smokers suffer from one or the other, while others suffer from both:
1. Chronic Bronchitis.
Heard of “smoker's cough”? It might be chronic bronchitis. This is a cough that “occurs most days of the week for three months, in at least two consecutive years”. That means that if you experience a cough that lasts for three months, two years in a row, then you may have chronic bronchitis. It can be caused by the inflammation and mucus the body produces to protect the lungs against damage from tobacco smoke.
Emphysema occurs when the air sacs in the lungs become damaged and deflated, making it impossible to take a full breath or inhale enough oxygen to support an active lifestyle.
In both forms of COPD, air becomes trapped in the lungs after a full exhalation, and the number of blood vessels in the lungs decreases. This means that there it takes more effort to breathe, and not enough oxygen reaches the blood. As the diseases progress, it becomes harder to breathe even when resting, and increases the risk of developing pneumonia and other lung infections.
Heightened White Blood Cells
Smokers have high levels of white blood cells – these are immune cells that defend the body against infections. Having a high level isn't as good as it sounds. It's a sign that the body is under stress and constantly fighting against inflammation and damage caused by tobacco smoke. Having heightened levels of white blood cells has been linked to an increased risk of heart attack, stroke, and cancer .
Slower Healing, Infections & Ulcers
Even with such high numbers of white blood cells, smokers take a longer time to heal from infections and wounds. Nutrients and oxygen are essential for all healing processes and these are delivered to the immune system via the blood. Smoking reduces blood flow throughout the body, and as a result, it takes longer for wounds to heal. Longer healing times increases the risk of infections, skin ulcers, and gangrene. 
Sick More Often & For Longer
Tar and other chemicals found in cigarette smoke weaken the immune system. This is called “immune system suppression” – smoking literally shuts down the body's ability to defend itself and maintain a healthy immune response. As a result, smokers are more likely to get sick, suffer from greater complications, and stay stick for longer .
Risk of Cancer
It's no secret that smoking is a major risk factor for many cancers, but did you know that 1 in 8 cancers are directly caused by smoking? When the immune system is suppressed, it is unable to detect or address the development of cancerous cells and their spread. Along with this, each inhalation of cigarette smoke contains over 70 known cancer-causing chemicals. 
Smoking has been linked to a heightened risk of:
- Lung cancers
- Breast cancers
- Mouth, throat, nose and sinus cancers
- Bladder, kidney and ureter cancers
- Oesophageal cancers
- Pancreatic cancers
- Stomach cancers
- Liver cancers
- Cervix and ovary cancers
- Bowel cancers
- Acute myeloid leukaemia 
Atherosclerosis, Heart Attack & Stroke
Atherosclerosis is a condition where the arteries throughout the body become partially blocked and hardened, adding resistance against natural blood flow. This increases blood pressure as the heart struggles to pump hard enough to push blood through the tighter space, putting strain on the heart. The blockages, made of hardened plaque, can break off and travel to smaller blood vessels where they may cause a complete blockage – this can cause stroke, heart attack and even death.
The heart, veins and arteries are all at risk of damage from tobacco smoke, and smoking significantly increases the risk of death due to atherosclerosis.
Inhaling tobacco smoke has been shown to:
- Raise blood pressure
- Increase formation of blood clots
- Weaken the walls of blood vessels
All of these lead to an increased risk of atherosclerosis, stroke, and heart attack.
This risk isn't just from smoke that you directly inhale from a cigarette – secondhand smoke is just as risky! Smoking around others can damage their cardiovascular systems, and even the lowest levels of second-hand smoke exposure can increase their risk of heart disease by 50% .
Coronary Heart Disease
Plaque can build up over time in the arteries that supply the heart muscles. Coronary heart disease occurs when the vessels to the heart are too blocked, and the heart cells don't receive enough blood and nutrients to function properly. For many people, the first sign of coronary heart disease is a heart attack.
Cold Hands & Feet
Because smoking constricts the blood vessels and can lead to blockages, the body can struggle to get blood to the tissues further from the heart – the hands and feet. Smokers can suffer from cold fingers and toes in any weather, but especially during the winter months. Without adequate blood flow to these areas, the nerves there can stop working, leading to a condition called peripheral neuropathy.
Hair, Skin & Nails
Wrinkles & Premature Ageing
Tobacco smoke literally changes the structure of skin cells and connective tissues, leading to premature ageing. It breaks down collagen, elastic fibres, and other structures that keep the skin taut. As these tissues give way, the upper layers of skin will sag and wrinkle – this occurs naturally as we age, but smokers experience this up to 20 years earlier than non-smokers! 
Nail Infections, Grey Hair & Balding
Smoking increases the risk of fungal nail infections, hair loss, premature pattern baldness, and grey hair. This is likely due to the effects of smoking on circulation, nutritional status, and the immune system. Without adequate blood flow and nutrients to the peripheral areas of the body (like fingers, toes, and the scalp), cells there are unable to produce strong proteins and pigments to form healthy hair and nails. A compromised immune system increases risk of infection in all areas of the body.
Sexual Health & Reproduction
Reduced Sexual Performance & Satisfaction
The genitals and sexual organs require blood flow and healthy nerve signals for sexual performance and satisfaction. Smoking can cause erectile dysfunction, decreased vaginal lubrication, and inability to reach orgasm .
Fertility Issues & Hormone ImbalanceSmokers, and people exposed to secondhand-smoke, frequently have fertility issues including delayed contraception and ectopic pregnancy . Smoking tobacco has been shown to throw hormone levels out of balance, particularly the hormones that regulate ovulation and fertility .Measurements of sperm quality including sperm volumes, sperm count, and sperm motility are consistently lower in smokers .
Smoking lowers oestrogen levels and may cause menopause to occur at least 1 year earlier than it otherwise would have . In turn, this can cause an even greater increased risk of menopause-related conditions like heart disease.
Muscles & Bones
Weak & Tired Muscles
Muscles need a lot of blood flow to supply them with the oxygen and nutrients they need to contract and grow stronger. With restricted blood flow, there isn't enough oxygen to maintain energy production in muscle cells, and muscles quickly become tired and can even atrophy.
Heard of the “beer belly”? Smoking causes fat to accumulate around the midsection just as significantly as alcohol use. Carrying weight around the waist is a risk factor for type 2 diabetes, cardiovascular disease and stroke .
Cramps, Aches & Pains
Smoking tobacco is actually an analgesic, or a pain-killer – but this only has a short-term effect. In the longrun, smoking causes more pain and is a risk factor for chronic pain conditions. Smokers tend to have more aches and pains than non-smokers. This is partially due to a lack of oxygen to the muscles, but also can be due to nerve damage. Smoking also increases the risk of a magnesium deficiency which can cause cramping, muscle stiffness, and pain. 
Brittle & Broken Bones
Smoking is a risk factor for osteoporosis and bone fractures. Chemicals found in cigarettes and tobacco itself may cause a decrease in bone density (a measurement that suggests how strong and healthy a bone is), and increase the chances of bones breaking . A large meta-analysis of all available literature concluded that 1 in 8 hip fractures are due to smoking .
Nervous System & Brain
Smoking cigarettes directly impacts the brain and nervous system in multiple ways. As an addictive substance, smoking tobacco creates new pathways through the brain and promotes the release of “feel good” neurotransmitters like dopamine and serotonin. Not only does this create an addictive pattern and painful “withdrawals”, it also contributes to conditions that affect the brain and nervous system.
Smoking is an addictive behaviour, and tobacco is an addictive substance. Addiction of any kind can be a risk factor for mental health conditions such as depression and anxiety, and can complicate conditions like schizophrenia.Studies have shown that while smokers often believe that cigarettes help them to “relax”, smoking actually increases anxiety and tension. It's unclear whether smoking contributes to the symptoms of depression, but most people start to smoke before they show signs of depression, not the other way around. 
Risk of Alzheimer's Disease
Smoking is a major risk factor for developing Alzheimer's disease and dementia. Many chemicals found in cigarette smoke are highly toxic to the brain and nerve fibres, and have been shown to cause changes associated with dementia and Alzheimer's onset .
Like all tissues in the body, nerves require oxygen and nutrients to function. Even occasional smoking pinches off the blood supply to nerves in peripheral areas like the fingers and toes. Over time, the lack of blood flow due to smoking damages the nerves, resulting in a condition called peripheral neuropathy or “peripheral nerve damage”.
Symptoms of peripheral nerve damage include:
- Muscle weakness
- Inability to feel vibration and touch
- Loss of reflexes
- Poor co-ordination
- Poor balance
- Hypersensitivity, e.g. experiencing pain for “no reason”
The 5 Senses
Due to its impact on various body systems, smoking also affects the organs that control our five senses
Eye Conditions & Poor Vision
Smoking is a major risk factor for many eye conditions that can lead to blindness, including glaucoma and age-related macular degeneration. Cataracts occur more frequently and more severely in smokers, and . These conditions tend to occur later in life, but younger smokers also have worse vision, greater inflammation in the eyes, and a higher risk of developing eye infections that can lead to blindness .
Insensitive to Touch
Peripheral nerve damage from smoking can make it impossible to detect touch in the hands, feet, and sometimes other parts of the body.
Loss of Taste & Smell
Both taste and smell are significantly impaired in smokers, making it difficult (or sometimes, impossible) to distinguish between the four major tastes of salty, sweet, bitter and sour. Because of this loss of taste and smell, eating healthy foods can become a chore rather than a pleasure, making it challenging to maintain a healthy weight. 
Risk of Hearing Loss
Smokers are more likely to suffer from hearing loss than non-smokers – even if that hearing loss is due to exposure to loud noises.  Smoking is also a risk factor for developing tinnitus, a high-pitched ringing in the ears .
The health impacts of smoking can seriously impact your quality of life – and your longevity. Isn't it time to switch?
 Higuchi, T., et al. (2016) Current cigarette smoking is a reversible cause of elevated white blood cell count: Cross-sectional and longitudinal studies. Prev Med Rep., 4, 417 – 422. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4995538/
 McDaniel, J. C., et al. (2014) Smoking, Chronic Wound Healing, and Implications for Evidence-Based Practice. J Wound Ostromy Continence Nurs., 41:5, 415 – E2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241583/
 Godoy, P., et al. (2018) Smoking may increase the risk of influenza hospitalization and reduce influenza vaccine effectiveness in the elderly. Eur J Public Health., 28:1, 150 – 155. https://www.ncbi.nlm.nih.gov/pubmed/29020390
 Centers for Disease Control and Prevention (US) (2010) How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. https://www.ncbi.nlm.nih.gov/books/NBK53010/
 Shi, Y., et al. (2010) Smoking and pain: pathophysiology and clinical implications. Anesthesiology., 113:114, 977 – 992. https://www.ncbi.nlm.nih.gov/pubmed/20864835
 Wong, P. K., et al. (2007) The effects of smoking on bone health. Clin Sci (Lond)., 113:5, 233 – 241. https://www.ncbi.nlm.nih.gov/pubmed/17663660
 Law, M. R., et al. (1997) A meta-analysis of cigarette smoking, bone mineral density and risk of hip fracture: recognition of a major effect. BMJ., 315. https://www.bmj.com/content/315/7112/841.abstract
 Choi, J., et al. (2015) Dose-response relationship between cigarette smoking and female sexual dysfunction. Obstet Gynecol Sci., 58:4, 302 – 308. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4515480/
 Kovac, J. R., et al. (2015) The Effects of Cigarette Smoking on Male Fertility. Postgrad Med., 127:3, 338 – 341. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4639396/
 Tuovinen, E., et al. (2016) Smoking status and abdominal obesity among normal- and overweight/obese adults: Population-based FINRISK study. Prev Med Rep., 4, 324 – 330. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4959936/
 Oboni, J., et al. (2016) Impact of smoking on fertility and age of menopause: a population-based assessment. BMJ Open., 6:11, e012015. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5128850/
 Ernster, V. L., et al. (1995) Facial wrinkling in men and women, by smoking status. Am J Public Health., 85:1, 78 – 82. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1615259/
 Whincup, P. H., et al. (2004) Passive smoking and risk of coronary heart disease and stroke: prospective study with cotinine measurement. BMJ., 329. https://www.bmj.com/content/329/7459/200.full
 Fluharty, M., et al. (2017) The Association of Cigarette Smoking With Depression and Anxiety: A Systematic Review. Nicotine Tob Res., 19:1, 3 – 13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5157710/
 Durazzo, T. C., et al. (2014) Smoking and increased Alzheimer’s disease risk: A review of potential mechanisms. Alzheimers Dement., 10:3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4098701/
 Galor, A. & Lee., D. J. (2011) Effects of smoking on ocular health. Curr Opin Ophthalmol., 22:6., 477 – 82. https://www.ncbi.nlm.nih.gov/pubmed/21897240
 Sung, J. H., et al. (2013) Relationship of cigarette smoking and hearing loss in workers exposed to occupational noise. Ann Occup Environ Med., 25, 8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3923356/
 Veile, A., et al. (2018) Is smoking a risk factor for tinnitus? A systematic review, meta-analysis and estimation of the population attributable risk in Germany. BMJ Open., 8:2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5855477/
 Vennemann, M. M., et al. (2008) The association between smoking and smell and taste impairment in the general population. J Neurol., 1121 – 1126. https://www.ncbi.nlm.nih.gov/pubmed/18677645