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What smoking is doing to your body

Learn about the harms smoking can do to our physical health.

Within 20 minutes of quitting smoking, your body begins a series of changes that will continue for years. 

Eyes

Smoking can cause changes in the eyes that can lead to blindness. A person who smokes is also more likely to develop cataracts or blind spots in their vision.

Skin and hair

Smoking reduces the skin’s elasticity and firmness (collagen and elastin), making it wrinkle and sag faster.

Smoking also weakens the skin’s blood circulation and increases the likelihood of acne and other skin infections.

Mouth

Smoking causes gum disease, and cancers of the mouth and throat. People who smoke may also have green phlegm, the "smoker's cough" and bad breath.

Cancer

Every time a person takes a puff of a cigarette, 4,500 chemicals, including 69 known carcinogens (substances that cause cancer), enter their lungs and spread to other parts of their body.

Smoking puts a person at increased risk of 16 cancers:

  • Lung
  • Mouth, throat, nose and sinus
  • Oesophagus
  • Bladder, kidney and ureter
  • Pancreas
  • Stomach
  • Liver cancer
  • Cervix and ovary
  • Bowel (colorectal cancer)
  • Acute myeloid leukaemia.

Lungs

Smoking makes breathing more difficult. Many people who smoke feel like they are breathing with their hand over their mouth and nose. This can make it harder to maintain a person’s fitness.

Smoking also damages the lungs. Your risk of getting lung cancer increases the earlier you start to smoke, the longer you smoke, and the more you smoke.

Stomach

The nicotine in cigarettes lowers the body's defenses against bad bacteria and can lead to peptic ulcers. People who smoke tend to suffer from more stomach acidity and reflux.

Pregnancy

A person who smokes while pregnant exposes their unborn baby to the chemicals in cigarettes. These chemicals are passed through the umbilical cord with no filter. This causes blood vessels to shrink and leaves the unborn child with a chronic shortage of oxygen throughout the pregnancy.

Smoking during pregnancy is associated with low birth weight, premature birth, prenatal death (both stillbirth and newborn deaths) and Sudden Unexpected Death in Infancy (SUDI). There may also be increased risk of miscarriage and ectopic pregnancy.

Genitals and sexual health

Sperm counts are much lower in people who smoke. Smoking also reduces blood flow to the penis so people who smoke are twice as likely to have problems maintaining an erection.

The liver of a person who smokes breaks down estrogen more efficiently, which can lower their libido.

Cigarette smoke also harms healthy protective bacteria, which can lead to more vaginal infections.

More information

Cost of smoking

Smoking also affects your financial health. Use the calculator to find out how much you'll save by quitting.

Try the tool

Contents of a cigarette

Find out what chemicals are in a cigarette and where else they're found. It'll help you understand the health effects.

Learn more

Available support

When you're ready to quit, check out what services are available locally and for free.

Get started
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You can use Smokefree even if you don't have mobile data. Go to zero.govt.nz on your phone and select 'Health New Zealand | Te Whatu Ora'.

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