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MedlinePlus is a service of the National Library of Medicine (NLM), the world's largest medical library, which is part of the National Institutes of Health (NIH). It was built as an online health information resource for patients and their families and friends.

MedlinePlus presents high-quality, easy to understand, relevant health and wellness information that is trusted.

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  • Sourced from more than 1,600 selected organizations.
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Smoking

What are the health effects of smoking?

There's no way around it; smoking is bad for your health. It harms nearly every organ of the body, some that you would not expect. Cigarette smoking causes nearly one in five deaths in the United States. It can also cause many other cancers and health problems. These include:

  • Cancers, including lung and oral cancers
  • Lung diseases, such as COPD (chronic obstructive pulmonary disease)
  • Damage to and thickening of blood vessels, which causes high blood pressure
  • Blood clots and stroke
  • Vision problems, such as cataracts and macular degeneration (AMD)

Women who smoke while pregnant have a greater chance of certain pregnancy problems. Their babies are also at higher risk of dying of sudden infant death syndrome (SIDS).

Smoking also causes addiction to nicotine, a stimulant drug that is in tobacco. Nicotine addiction makes it much harder for people to quit smoking.

What are the health risks of secondhand smoke?

Your smoke is also bad for other people - they breathe in your smoke secondhand and can get many of the same problems as smokers do. This includes heart disease and lung cancer. Children exposed to secondhand smoke have a higher risk of ear infections, colds, pneumonia, bronchitis, and more severe asthma. Mothers who breathe secondhand smoke while pregnant are more likely to have preterm labor and babies with low birth weight.

Are other forms of tobacco also dangerous?

Besides cigarettes, there are several other forms of tobacco. Some people smoke tobacco in cigars and water pipes (hookahs). These forms of tobacco also contain harmful chemicals and nicotine. Some cigars contain as much tobacco as an entire pack of cigarettes.

E-cigarettes often look like cigarettes, but they work differently. They are battery-operated smoking devices. Using an e-cigarette is called vaping. Not much is known about the health risks of using them. We do know they contain nicotine, the same addictive substance in tobacco cigarettes. E-cigarettes also expose non-smokers to secondhand aerosols (rather than secondhand smoke), which contain harmful chemicals.

Smokeless tobacco, such as chewing tobacco and snuff, is also bad for your health. Smokeless tobacco can cause certain cancers, including oral cancer. It also increases your risk of getting heart disease, gum disease, and oral lesions.

Why should I quit?

Remember, there is no safe level of tobacco use. Smoking even just one cigarette per day over a lifetime can cause smoking-related cancers and premature death. Quitting smoking can reduce your risk of health problems. The earlier you quit, the greater the benefit. Some immediate benefits of quitting include:

  • Lower heart rate and blood pressure
  • Less carbon monoxide in the blood (carbon monoxide reduces the blood's ability to carry oxygen)
  • Better circulation
  • Less coughing and wheezing

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