Smoking damages nearly every organ in the body. People can significantly reduce their chance of smoking-related disease by giving it up.

Smoking is the leading preventable cause of early disease and death in the United States. Giving up smoking is difficult for many people, but the number of former smokers is increasing all the time.

According to the Centers for Disease Control and Prevention (CDC), current smoking in the U.S. has declined from 20.9% in 2005 to 13.7% in 2018. The number of smokers who have quit is also rising.

In this article, we look at the health impact of smoking, including its effects on the brain, heart, lungs, and immune system. We also discuss the benefits of quitting.

Every year, more than 480,000 people die in the U.S. due to tobacco-related diseases — around 1 in 5 of all deaths — according to the American Cancer Society.

They also state that around half of people in the U.S. who keep smoking will die from smoking-related causes.

Life expectancy is at least 10 years less for smokers compared with nonsmokers. The American Cancer Society state that smoking shortens lifespan by about 12 years in males and 11 years in females.

The CDC comment that smoking causes more deaths in the U.S. each year than the following combined:

  • motor vehicle injuries
  • alcohol or illicit drug use
  • firearm-related incidents

Tobacco contains poisonous substances that affect people’s health. Two of these poisons are:

  • Carbon monoxide. Car exhaust fumes also produce this substance, and it is fatal in large doses. It replaces oxygen in the blood and starves the organs of oxygen, stopping them from functioning correctly.
  • Tar. This is a sticky, brown substance that coats the lungs and affects breathing.

While the statistics are alarming, it is important to bear in mind that giving up smoking reduces the risk of disease dramatically.

Below, we discuss the impact smoking can have on different parts of the body.

Smoking can increase the likelihood of having a stroke by 2–4 times. Strokes can cause brain damage and death.

One way that stroke can cause brain injury is through a brain aneurysm, which occurs when the wall of a blood vessel weakens and creates a bulge. This bulge can burst and cause a subarachnoid hemorrhage, which can lead to a stroke.

Chemicals in tobacco smoke increase the chance of heart problems and cardiovascular diseases.

Smoking causes atherosclerosis, which is when plaque builds up in the blood and sticks to the artery walls. This makes them narrower, reducing blood flow and increasing the risk of blood clots.

Smoking also damages the blood vessels, making them thicker and narrower. This makes it harder for blood to flow, and also increases blood pressure and heart rate.

Smoking has links with the following cardiovascular conditions:

  • coronary heart disease, one of the leading causes of death in the U.S
  • a heart attack, as smoking doubles the risk of heart attack
  • blockages that reduce blood flow to the skin and legs
  • stroke due to blood clots or burst blood vessels in the brain

Even smokers who smoke 5 or fewer cigarettes a day may develop early signs of cardiovascular disease.

Carbon monoxide and nicotine make the heart work harder and faster. This means that smoking makes it more challenging to exercise. A lack of exercise further increases the risk of health problems.

According to the National Institutes of Health (NIH), smoking reduces bone density, making the bones weaker and more brittle. Smoking can also impair bone healing after a fracture.

Researchers find it difficult to say whether this is a direct effect of smoking, or due to other risk factors prevalent in people who smoke. These include lower body weight and doing less physical exercise.

This may affect females more than males. Females are more prone to osteoporosis and broken bones.

Quitting smoking, even later in life, can help limit bone loss linked with smoking.

The immune system protects the body against infection and disease.

According to one 2017 study, smoking reduces immune function and causes inflammation in the body. This can lead to autoimmune conditions, including:

Smoking also has links with type 2 diabetes.

The lungs are perhaps the most obvious organ that smoking affects.

It often takes many years before a person notices any symptoms of smoking-related lung disease. This means that people may not receive a diagnosis until the disease is quite advanced.

Smoking can impact the lungs in several ways. The primary reason is that smoking damages the airways and air sacs — known as alveoli — in the lungs.

Three of the most common smoking-related lung conditions in the U.S. are:

  • Chronic obstructive pulmonary disease (COPD). COPD is a long-term disease. It causes wheezing, shortness of breath, and chest tightness. COPD is the third leading cause of death in the U.S.
  • Chronic bronchitis. Chronic bronchitis occurs when the airways produce too much mucus. This leads to a long-lasting cough and inflamed airways. Over time, scar tissue and mucus can completely block the airways and cause infection.
  • Emphysema: Emphysema is a type of COPD that reduces the number of alveoli and breaks down the walls between them. This makes it difficult to breathe, even at rest, and over time, a person may need an oxygen mask.

Other lung diseases caused by smoking include pneumonia, asthma, and tuberculosis.

Smoking can have several effects on oral health and may cause:

  • halitosis, or bad breath
  • stained teeth
  • dry mouth
  • reduced sense of taste

Smoking irritates the gum tissues. The American Dental Association (ADA) state that smoking increases the risk of gum disease, which can add to halitosis.

Smoking can also affect the reproductive system and fertility.

Females who smoke can have more difficulty becoming pregnant. In males, smoking can cause impotence by damaging blood vessels in the penis. It can also damage sperm and affect sperm count.

According to some studies, males who smoke have a lower sperm count than those who do not.

Smoking while pregnant increases a number of risks for the baby, including:

  • premature birth
  • pregnancy loss
  • low birth weight
  • sudden infant death syndrome
  • infant illnesses

Smoking reduces the amount of oxygen that can reach the skin. This speeds up the aging process and can make skin appear dull or gray.

Smoking can cause:

  • facial wrinkles, especially around the lips
  • baggy eyelids
  • uneven skin coloring, such as a yellow or gray tone
  • dry, coarse skin
  • temporary yellowing of the fingers and fingernails

Smoking reduces how quickly skin wounds heal, increases the risk of skin infections, and increases the severity of skin conditions, including psoriasis.

Smoking increases the risk of many types of cancer. According to the National Cancer Institute, tobacco smoke contains around 7,000 chemicals, of which at least 69 can cause cancer.

Figures from the American Cancer Society state that smoking causes around 30% of all cancer deaths in the U.S., and 80% of all lung cancer deaths.

Lung cancer is the leading cause of cancer death in both men and women. It is one of the most difficult to treat.

Smoking is a risk factor for the following cancers:

Cigars, pipe-smoking, menthol cigarettes, chewing tobacco, and other forms of tobacco all cause cancer and other health problems. There is no safe way to use tobacco.

Read more about how smoking affects the body here.

While the statistics are alarming, the good news is that quitting smoking reduces the risk of disease and death significantly. The risks drop further, the longer a person refrains from smoking.

In fact, some research says that quitting before the age of 40 reduces the risk of dying from smoking-related disease by about 90%.

These statistics illustrate the health benefits of quitting smoking:

  • Cardiovascular risks: After 1 year of quitting, the risk of having a heart attack drops sharply.
  • Stroke: Within 2–5 years, the risk of a stroke reduces to half that of a non-smoker.
  • Cancers: The risks for mouth, throat, esophagus, and bladder cancer drop by half within 5 years of quitting, and 10 years for lung cancer.

Soon after quitting, people experience the following health benefits that can significantly improve their quality of life and serve as reminders of the health benefits that quitting can have:

  • breathing becomes easier
  • daily coughing and wheezing reduces then disappears
  • sense of taste and smell get better
  • exercise and activities become easier
  • circulation to the hands and feet improves

Read more about what happens when you quit smoking here.

Though quitting can be stressful, people often start to notice their daily stress levels are much lower than when they were smoking within 6 months or so.

Quitting smoking is a different journey for everyone, and what works for one person will not always work for the next. Try out a few different ways to see which ones work best.

When trying to quit smoking, these tips may help:

  • Make lists of reasons why it is a good idea to quit. Read over these when the temptation to smoke strikes.
  • Use an app to track your progress. Reaching milestones, such as a day without smoking, can help motivate a person to continue. There are many free and paid apps on the market.
  • Try nicotine replacement products. Nicotine patches, gums, and lozenges can help reduce cravings, making it easier to resist at any particular moment.

Many people find that reaching out to a healthcare provider for support can help them quit for good.