Health Effects of Smoking

It’s common knowledge that smoking is bad for your health – different chemicals and compounds in tobacco adversely affect every system in the body and cause numerous diseases, worst of which is cancer.

However, while smokers do know that smoking is not beneficial to their health, most of them do not know to which extent they are harming their body. This guide will focus on various systems in the body and the effects of smoking on each one of them.

Central Nervous System

Nicotine has a profound effect on the central nervous system and its effects can be easily recognized when smokers go through a withdrawal period. Intense mood swings, bouts of anxiety and depression, and diminished cognitive abilities are all brought on by nicotine deficiency. Smokers are also more inclined to be nervous, restless, and have problems concentrating. These effects are not only noticeable during the cessation period, either. Certain studies show that two hours without a cigarette are enough for smokers to start experiencing psychological effects of nicotine deprivation.


Recent studies done at the Indian National Brain Research Center suggest that tobacco can have a detrimental physical effect on the brain. It focuses on the compound NNK, a procarcinogen which is found in cigarettes and other tobacco products. NNK is believed to activate microglia cells, which usually only destroy unhealthy or foreign brain cells. However, researchers discovered that NNK-activated microglia cells attack healthy brain cells and that this process leads to neuro-inflammatory conditions.


Smoking also affects vision. Smokers are twice as likely to develop cataracts as non-smokers. Cataracts are clouding of the eye’s lens and they are one of the leading causes of blindness in the world.

Also, smokers have an increased risk of:

  • Uveitis – inflammation of the middle layer of the eye. This condition can also lead to permanent blindness. Smokers are 2.2 times more likely to develop uveitis.
  • Macular degeneration – usually age-related, macular degeneration causes blinds spots. Smokers have three times higher chances of developing age-related macular degeneration than non-smokers.
  • Diabetic retinopathy – a secondary condition related to diabetes. It causes vision loss by damaging blood vessels that supply the retina. In smokers, the condition progresses more rapidly than in non-smokers.
  • Dry eyes – smokers are constantly enveloped in tobacco smoke which causes dry eyes and leads to eye inflammations.

Taste and Smell

Various types of cancer and other diseases that smoking causes get a great deal of attention. Unfortunately, the same is not true for the effect that smoking has on two very important senses – taste and smell.

Smoking leads to flattened taste buds and restricts the formation of tiny blood vessels that help taste buds to grow and develop. While the number of those buds is the same in smokers and nonsmokers, their level of sensitivity is not. Smokers can’t enjoy the same nuances when it comes to taste that non-smokers can and smoking diminishes the pleasure people get from eating foods they like.

Studies also show that smoking has a detrimental effect on the sense of smell. Smokers have difficulty smelling faint and nuanced smells and everything they can pick up has a distorted smell when compared to what non-smoker might smell. Also, smoke can aggravate the nasal passage and the sinuses, causing inflammation that can further damage the sense of smell. It takes years for the sense of smell to restore itself to the pre-smoking levels.

Respiratory System

Smoking damages the lungs slowly but the damage done is deadly. Our lungs have a housekeeping system developed to keep them clean and disease-free and smoke interferes with that system. Smoking damages the cilia cells that are responsible for sweeping particles and irritants out towards the mouth. With cilia cells gone, different pathogens and toxins now have an open path towards lung alveoli – small sacs that fill with air, enabling us to breathe.

Respiratory Infections

Respiratory infections are common in smokers. As mentioned, cilia cells are responsible for keeping the lungs clean and working. When they are gone – and they start to die out with the first inhale a smoker takes and are severely damaged within a year – different bacteria and viruses have a clear path to the lungs. Mucus also accumulates faster, making it harder to breathe and expel that toxic build-up from the lungs.

Smokers tend to cough a lot in an effort to get rid of that mucus that is clogging up their airways. Coughing is always worse in the morning because the mucus has had the time to accumulate overnight.

Chronic Obstructive Pulmonary Disease

Also known as COPD, chronic obstructive pulmonary disease is actually a set of respiratory diseases that affect smokers predominately. COPD is a progressive disease, meaning that it only gets worse over time.

Two main conditions that fall under COPD are:

  • Emphysema – lung air sacs are damaged, which reduces the amount of gas exchange in the lungs and leads to troubles breathing. Smoker’s emphysema can have fatal consequences and worst case scenarios require lung transplantation.
  • Bronchitis – chronic bronchitis places the lungs under a lot of stress. Air sack walls are constantly inflamed, which causes mucus build-up and difficulty breathing.

COPD is mostly diagnosed in middle-aged and older smokers but that doesn’t mean that young smokers don’t have it. At best, it means that the disease has not progressed enough to become noticeable. COPD has no cure but lifestyle changes – including cessation – can reduce symptoms and make the disease more manageable.


Asthma is a lung disease that is extremely dangerous if left unchecked. Asthma patients have difficulty breathing due to constantly inflamed tubes that carry air to the lungs. Smoking can seriously exacerbate symptoms of an asthma attack and can serve as a trigger for the attack to occur.

Both smoke and asthma target bronchial tubes in the lungs. In asthmatic patients, they are already constantly inflamed and smoke only serves to make matters worse. People with asthma are advised not to smoke at all and to stay clear of smoke-filled spaces in order to avoid having an asthma attack.

The Flu and the Cold

Smoking also worsens the cold and the flu – in addition to other viral diseases. Researchers have found that smokers have overactive immune systems that make viral infections worse by not delivering an appropriate response. The immune system goes into overdrive and causes systematic inflammations that damage the body more that the virus – especially the already sensitive tissues in the lungs.

Also, smoking while under the influence of a common cold puts your lungs under even more stress. They are already inflamed because of the cold – adding smoke to the mix does not benefit the situation.

Lung Cancer

Due to the fact that cigarette smoke contains nearly 70 known carcinogens, lung cancer is mostly a smoker’s disease. Smoke damages the cells and starts altering them on a molecular level – tumor cells begin to grow in the damaged lung tissue.

Most common types of lung cancer are:

  • Small cell lung cancer
  • Non-small cell lung cancer – includes several types of lung cancer

Both types are deadly and nearly 90% of patients diagnosed with either of them don’t survive more than 5 years after the initial diagnosis.

Cardiovascular System

Even casual smokers are damaging their cardiovascular system if they smoke regularly during an extended period of time. This is because smoking causes a permanent increase in blood pressure, damaging the blood vessels and starting a chain reaction that can lead to heart attack, stroke, loss of circulation to limbs, and more.

Peripheral Artery Disease and Atherosclerosis

P.A.D. is a condition in which blood vessels tighten and become narrow due to plaque build-up. Nicotine and smoke are partly responsible for it in smokers. As those vessels tighten less blood is delivered to the organs – the heart has to go into overdrive in order to deliver an already limited supply of oxygen to various cells (oxygen is limited due to compromised lung function). P.A.D can lead to stroke and/or heart attack.


Smoking reduces ‘good’ cholesterol (HDL) significantly, putting smokers at an even higher risk of suffering a heart attack. On the other hand, research also shows that smoking can have an effect on bad cholesterol – LDL becomes more oxygenated and can cause inflammation.


Benzene, an ingredient in cigarettes, is linked to acute myeloid leukemia, a type of blood cancer. The risks of developing the disease increase with the number of years you smoke and the number of cigarettes you smoke in a day.

Other Effects of Smoking on the Cardiovascular System

If the above mentioned is not scary enough, smoking also causes several other alarming conditions that will have you questioning your smoking habit.

  • Reduces coronary blood flow and can cause dying of the heart muscle
  • Stimulates the clotting process and increases the risk of blood clots forming
  • Increases blood sugar while obstructing insulin release
  • Doubles the chances of ischemic stroke
  • Increases the heart rate

Digestive System

Smoking wreaks havoc on the digestive system – from the mouth all the way down to the rectum; every single organ is affected by tobacco smoke.

While lung cancer is the most prevalent form of cancer in smokers, it is by all means not the only one.

  • Head and neck cancers – smokers put themselves at risk of developing head and neck cancers during their lifetime. Most common ones are oral cavity cancers, including oropharynx, hypopharynx, and larynx cancers. Nearly 75% of those cancers can be attributed to either tobacco or alcohol.
  • Pancreatic cancer – smokers have an increased chance of getting pancreatic cancer. 20 – 30% of all pancreatic cancers can be linked to smoking.
  • Esophageal cancer – one type of esophageal cancer, the squamous cell esophageal cancer, is linked to smoking.
  • Liver cancer – while smoking does not cause liver cancer it dramatically increases the likelihood of it forming in people who are predisposed and have cirrhosis or hepatitis A or B.
  • Stomach cancer – Smokers are at risk of getting stomach cancer. Their chances of it developing are roughly two times higher than for non-smokers.
  • Kidney cancer – smokers have a 50% higher chance of developing kidney cancer than non-smokers. The risk increases for smokers who smoke more than 20 cigarettes a day – they are three times more likely to develop cancer in the renal pelvis region than are non-smokers.
  • Bladder cancer – Half bladder cancers in both women and men can be attributed to smoking. Smokers are three times more likely to suffer from it than non-smokers.
  • Colorectal cancer – Female smokers are 20% more likely to develop colorectal cancer than non-smokers. Male smokers have an 8% higher chance of developing it when compared to male non-smokers.

Almost every type of cancer that affects the digestive system can be caused and exacerbated by smoking. Of course, cancer is not the only disease associated with smoking and there are others – some are less deadly but arguably equally debilitating since they are chronic and painful.

Gum Disease

Other than causing various types of oral cancer smoking is also linked to several other oral ailments that are anything but pleasant. These include:

  • Tooth discoloration – various compounds from cigarette smoke deposit on teeth, turning them yellow and discolored.
  • Bad breath – smokers smell of smoke but can also have infected gums that can lead to halitosis.
  • Inflammation – various types of inflammations can occur in the mouth, including tooth inflammation, gum inflammation, and salivary gland inflammation.
  • Plaque build-up – smoking causes plaque build-up, which damages the teeth and can lead to cavities and tooth loss.
  • Decreased jaw bone – jaw is very sensitive and research suggests that smoking causes bone density to diminish in that particular area. This can lead to irreversible tooth loss.
  • Other complications – smoking slows the healing process and reduces the success rate of dental implant surgeries.

Heartburn and GERD

Heartburn is uncomfortable reflux that causes pains in the chest and is, in essence, your stomach contents flowing back to the esophagus. Acids from the stomach contents damage the esophageal lining and this can lead to serious health problems. Smoking weakens the lower sphincter that usually prevents the backflow – thus aiding and abetting heartburn.

GERD is an advanced form of heartburn – chronic one. It happens at least twice a week. Smoking can worsen the symptoms, causing ulcers and bleeding.

Peptic Ulcers

Smokers have an increased chance of developing peptic ulcers. Peptic ulcers are painful and occur in the stomach and the duodenum. Smoking increases the risk of infections which cause them and slows down the healing process.

Colon Polyps

Smokers are at an increased risk of developing colon polyps as well. Theirs are larger in size, more numerous, and are more likely to recur.

Type 2 Diabetes

Type 2 diabetes is the most common type of diabetes in adults and it accounts for 90% of all diabetic disorders. Smokers are 30 to 40% more likely to develop it and in case they continue smoking the habit will exacerbate their condition and cause other health issues, such as:

  • Heart complications
  • Kidney disease
  • Poor circulation
  • Loss of sight
  • Neuropathy

Also, smokers have a difficult time controlling their condition as it’s harder to regulate insulin dosage for smokers.


Nicotine boosts the level of blood sugar while at the same time preventing insulin from excreting in normal quantities. That is why smokers tend not to feel hungry after a cigarette, even if it has been a while since their last meal. While smokers might get a temporary relief from hunger by smoking a cigarette, the negative effects outweigh the positive ones by far. Smoking is not a viable option for dieting and being 50 pounds overweight is actually healthier than smoking a pack of cigarettes a day.

Other Effects of Smoking on the Digestive System

Smokers have a higher chance of developing several other digestive system diseases, such as:

  • Crohn’s disease
  • Pancreatitis
  • Fatty liver disease
  • Primary biliary cirrhosis
  • Gallstones

With patients with pre-existing conditions, smoking can worsen the symptoms and hinder the healing process considerably.

Reproductive System

Smoking can be linked to reproductive system issues in both men and women. Men who smoke are more likely to suffer from erectile dysfunction that will last more than a month at one point in their lives – non-smokers have a 20% lower chance of experiencing the same.

Also, smoking is linked to lower sperm count and damaged sperm. Some of the ingredients that can be found in cigarettes can easily alter the genetic material found in sperm and research suggests that children of male smokers are more likely to develop cancers during their childhood years.

Smokers also have an increased chance of getting penile cancer and some studies show that a link can be found between prostate cancer and cigarette smoke, although further study is needed in this area.

Effects that smoking has on female reproductive health are considerably more noticeable, and one can argue, more serious. When compared to non-smokers, women smokers are more likely to suffer from:

  • Reduced fertility
  • Menstrual irregularities and cramps
  • Early menopause
  • Cervical cancer
  • Vulvar cancer

Also, female smokers over the age of 35 who are using oral contraceptives have a higher risk of getting a heart attack than women who do not smoke.


Smoking is highly detrimental to the development of a fetus.  In general, women who smoke give birth to children with lower weight and are more likely to deliver preterm. Unfortunately, only around 50% of female smokers report quitting the habit during pregnancy and around 10% smoke even in the last trimester.

Pregnant smokers risk:

  • Placental abruption – placenta gets separated, causing distress to the baby and in some cases even stillbirth
  • Premature delivery and low birth weight – babies are more sickly and gain weight at a slower pace, which might necessitate a longer hospital stay
  • Miscarriage – female smokers have more miscarriages than women who do not smoke
  • Birth defects – babies are more likely to be born with one or more birth defects, such as a cleft palate or a cleft lip
  • Contributing factor to SIDS – Sudden Infant Death Syndrome has no discernible cause but some research suggests that it might occur more frequently if the mother smoked during pregnancy

Of women smokers who quit during pregnancy, 30% will start smoking within first 6 months after the delivery. Secondhand smoke puts babies at a higher risk for developing asthma or having frequent ear infections.

Immune System

Smokers tend to have a harder time fighting the common cold and the flu. The reason is their compromised immune system. Research suggests that some ingredients in a cigarette, nicotine in particular, weaken the immune reaction considerably.

Smoking affects the immune system in a variety of ways and is responsible for:

  • More frequent and prolonged common infections
  • Reduced number of antioxidants in blood, such as vitamin C
  • Frequent respiratory infections

Smoking might also trigger an autoimmune response, especially in the lungs. Due to constant respiratory infections, antibodies can get confused and start attacking normal cells instead of the sick ones.

However, there is research that suggests completely the opposite. Some findings indicate that because of the weakened immune system, smokers tend to have fewer neurodegenerative diseases. Nicotine acts as a suppressant and can be considered a neuroprotective agent. More research is needed on this front and even if it proves to be true smoking causes too much damage to other systems to be considered a viable therapy.

Skeletal System

Constant backache and brittle bones can also be attributed to smoking. Studies indicate that smokers are twice as likely to suffer from lower back pain as non-smokers. Nicotine also slows down the healing process so broken bones take more time to heal and mend properly.

Smoking affects:

  • Bone production by slowing it down considerably
  • Bone loss
  • Vertebral discs – disc degeneration is more prominent and more severe in smokers
  • Ligaments – smokers have weaker ligaments, especially in the spinal area
  • Healing process – smokers heal more slowly, especially after complex orthopedic surgeries
  • Treatment success – bone and ligament surgery is less successful on smokers

Integumentary System

The integumentary system is the largest bodily system and it consists of skin and glands, hair, and nails. It’s also on the forefront of the battle with cigarette smoke. Toxins from the smoke adversely affect the skin they come into contact with – they cause discoloration and loss of elasticity.

But it doesn’t stop there. Smoking also reduces the amount of oxygen that is circulating through the body, meaning that skin gets fewer nutrients than it normally would. This leads to premature skin aging.

The same is true of hair and finger nails. Nails become brittle and more prone to breaking and smokers can also expect a reduced hair growth rate and fragile and problematic hair.

Smoking has been found to:

  • Decrease vascularization of the skin
  • Increase chances of getting skin cancer by 2 times
  • Increase chances of getting psoriasis
  • Cause acne outbreak
  • Cause premature hair loss and hair graying
  • Cause discoloration of fingers and skin in general

Smoking also causes teeth discoloration, bad breath, and can be partially related to body odor. Smoke clings to both skin and hair and smokers tend to give it off to such an extent that it’s noticeable even outdoors.

Work Productivity

Smoking is also responsible for hundreds of millions of dollars lost by companies every single year due to lower productivity rates of smokers compared to those of non-smokers. This is not surprising because, on average, smokers are sick one extra day longer every year.

  • Male smokers 4.36 days of sick leave – Male non-smokers 3.30
  • Female smokers 4.96 days of sick leave – Female non-smokers 3.75

This costs the companies roughly $184 million dollars per year.

Also, smokers take more breaks than non-smokers. For male smokers, the total amounted to 9 days of smoking breaks per year while for female smokers it amounted to 6 days per year. These breaks cost the employers $788 million dollars every year!

Final Word about Smoking Effects

All the evidence points to smoking being one of the worst health hazards since the black plague- the number of smoking-related deaths will soon topple 8 million per year. Quitting is hard but living with a debilitating illness is even harder so take control of your life and start minimizing the negative effects that smoking has had on your health so far. Ditch the habit now – every single system in your body will thank you for it.