How smoking affects the liver

Last updated Feb. 13, 2024, by Susie Strachan
Fact-checked by Patricia Silva, PhD

When you use tobacco products, such as cigarettes or electronic cigarettes, it exposes your body, including your liver, to nicotine and other harmful chemicals.

Constant exposure to tobacco’s toxic components can put a strain on your liver, which has to work to remove toxins from your body. Over time, this can affect your liver health by causing inflammation, tissue damage, and affecting the liver’s ability to function normally.

Smoking is also a known risk factor for diseases of the liver such as nonalcoholic fatty liver disease (NAFLD), cirrhosis, and liver cancer.

The impact of smoking on your body

When you smoke tobacco, your body is exposed to harmful chemicals such as nicotine, tar, and carbon monoxide.

One of the liver’s main functions is to filter and detoxify your blood of harmful substances, such as from tobacco.

Tobacco use plays a significant role in preventable illness and mortality in the U.S., contributing to 1 in 5 deaths.

According to the Centers for Disease Control and Prevention, nearly half a million Americans die each year prematurely from smoking cigarettes. Another 16 million live with a serious illness related to smoking.

While some of the more common conditions connected to cigarette smoking are lung cancer and chronic obstructive pulmonary disorder (COPD), smoking also can damage your liver in the following ways:

• It introduces harmful substances that can potentially lead to inflammation and damage.
• It can cause changes in the immune system and decrease your immune response.
• It has been linked to an increased risk of certain cancers, such as ​​hepatocellular carcinoma — the most common type of primary liver cancer — in people with a chronic hepatitis B or C virus infection.

There is some evidence that cigarette smoking may contribute to the progression of fibrosis (scarring of liver tissue) in NAFLD and primary biliary cholangitis.

It has also been linked to liver cancer, which is the fifth most common cancer and third-highest cause of cancer-related deaths globally.

If you have had a liver transplant, smoking can potentially affect blood flow to the transplanted organ, causing the new organ to be rejected or leading to liver cancer.

Secondhand smoke may also cause passive smoking liver damage, from being exposed to cigarette smoke.

Cannabis and the liver

Smoking cannabis can also harm the liver.

While the primary compounds of cannabis — tetrahydrocannabinol and cannabidiol — have been studied for therapeutic use in general, research on the effects of cannabis on the liver is ongoing.

For more information about using cannabis, speak with your doctor. But also be aware of the laws regarding cannabis use where you live.

In the U.S, individual states have different rules about legalization, decriminalization, recreational and medical use, and limits on personal possession.

Smoking and liver diseases

It is believed that smoking is one of the environmental factors that can affect the development and progression of one of the most common forms of chronic liver disease, NAFLD, along with cirrhosis of the liver.

Cirrhosis occurs in advanced stages of liver disease. Liver tissue becomes severely scarred (fibrosis) and unable to function properly. Once a liver becomes cirrhotic, the tissue damage is permanent.

Smoking has been shown to increase the risk of developing liver cancer by 50% compared with people who have never smoked.

There may be a link between cirrhosis, smoking, and being diagnosed with hepatocellular carcinoma, which is the most common type of primary liver cancer.

Being a longtime smoker is also a known risk factor for developing primary biliary cholangitis, which causes progressive damage to the small bile ducts within the liver.

E-cigarettes and vaping

The Food and Drug Administration has classified e-cigarettes as “tobacco products” because most of them contain some amount of nicotine from tobacco.

Using e-cigarettes is also known as vaping. When vaping, an aerosol is inhaled. The aerosol contains nicotine and other substances that are addictive and can cause liver disease. It also can cause lung disease, heart disease, and cancer, according to the American Cancer Society.

The long-term health effects of e-cigarettes on the liver are not yet fully understood. But they do contain potentially harmful substances such as volatile organic compounds (VOCs). VOCs may include compounds such as formaldehyde, acrolein, and benzene, which have the potential to damage the liver.

Quitting smoking

When you stop smoking, your liver health may improve. Your liver has the potential to regenerate itself after injury, including from smoking.

By quitting smoking, you are no longer exposing yourself to toxins in tobacco that can be absorbed into the bloodstream and may contribute to liver damage.

Quitting also can help decrease inflammation in your body, which is a risk factor for various liver diseases, including NAFLD.

Resources and support

SmokeFree.gov offers a number of tools to quit smoking.

1-800-QUIT-NOW offers coaching, educational materials, and referrals to local resources.

The American Cancer Society also has educational materials to help make quitting smoking a bit easier.

Liver Disease News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.