Evidence that smoking causes non-Hodgkin’s lymphoma is mixed. However, smoking might create molecules that could prevent the destruction of cancerous cells. In general, smoking increases the risk of several types of cancer.

Tobacco smoke contains at least 70 chemicals known to cause cancer, such as formaldehyde, nicotine, and lead.

Smoking increases your chances of lung cancer by 15 to 30 times. It has also been linked to an increased risk of many other types of cancer, including lymphoma.

Lymphoma is a type of cancer that develops in white blood cells called lymphocytes. It’s divided into two primary categories: Hodgkin’s lymphoma (HL) and non-Hodgkin’s lymphoma (NHL).

Some research suggests that smoking may be associated with a subtype of NHL called follicular lymphoma, but studies have found mixed results.

In this article, we review what’s currently known about smoking and the risk of NHL.

The American Cancer Society estimates that 80,350 people in the United States will receive an NHL diagnosis in 2025. Researchers continue to examine a potential link between smoking and NHL. Some studies suggest a connection, but current evidence is mixed.

Theoretically, chemicals in tobacco smoke could lead to genetic mutations that cause lymphocytes to replicate uncontrollably. But the exact process by which smoking could cause lymphoma remains mostly unexplained.

Some research has suggested that cigarette smoking may change the immune response by producing molecules called Th2 cytokines. These molecules may prevent the destruction of cancerous lymphocytes.

One group of cancer-causing chemicals in tobacco smoke, called aromatic hydrocarbons, can cause mutations in the TP53 gene.

Mutations in this gene are present in 5% to 6% of people with follicular lymphoma. These mutations are associated with reduced survival. Follicular lymphoma is the second most common type of NHL.

What are 95% confidence intervals?

Researchers use a 95% confidence interval (CI) to express a range of values that they can say with 95% certainty contains the true average.

For example, if they find that people who smoke have a 2.0 times higher chance (95% CI: 1.9 to 2.1) of developing a type of cancer, they can say with 95% certainty that people who smoke have between a 1.9 and 2.1 times higher chance of developing that cancer.

Smoking and follicular lymphoma (a subtype of NHL)

Some groups of researchers have found a moderate association between smoking and follicular lymphoma, although study results have been conflicting. Follicular lymphoma is a subtype of NHL.

The authors of a 2020 research review concluded that most studies did not support an association between smoking and follicular lymphoma.

However, a 2022 study in Australia with the same lead author found a consistent association between smoking and increased follicular lymphoma risk. The study authors also found:

  • evidence of higher risk with an increased amount of smoking
  • an association between smoking and reduced survival after diagnosis
  • a possible association between smoking and a lower survival rate for follicular lymphoma specifically
  • an increased risk of follicular lymphoma among nonsmokers who were exposed indoors to more than two smokers during childhood

In a 2018 study in the United Kingdom, researchers examined cancer rates among 211,005 smokers and 211,005 nonsmokers over a 30-year period. They found:

  • Male smokers had a 7% (95% CI: 4% to 7%) higher and female smokers had a 3% (95% CI: 0% to 6%) higher chance of developing any cancer than nonsmokers.
  • Men who smoked had a 24% (95% CI: 13% to 36%) higher chance of developing lymphoma than nonsmokers.
  • Female smokers had a 2% (95% CI: -7% to 11%) increased chance of developing lymphoma. This CI means that it was not clear whether female smokers had a higher or lower chance of developing lymphoma.

Smoking and Hodgkin’s lymphoma

Current research suggests that smoking is most associated with the development of HL and follicular lymphoma.

Studies suggest that smoking cigarettes is associated with a modestly increased risk of HL but a 60% to 80% increased risk of some subtypes.

The authors of a 2021 review noted that smoking is not linked to most subtypes of NHL. However, smoking and obesity are highly associated with diffuse large B-cell lymphoma, the most common type of NHL.

A 2017 study in Italy found that people who smoked more than 15 cigarettes per day had a 42% (95% CI: 2% to 97%) increased risk of developing NHL and a 147% (95% CI: 25% to 387%) increased risk of HL.

No increased risk was found for people who smoked fewer than 15 cigarettes per day or for former smokers. Smoking duration was associated with increased HL risk but not NHL risk.

Immune system suppression and viral infections are the most important risk factors for NHL. According to the American Cancer Society, in the United States, the risk is also higher in the following groups of people:

  • older adults — especially those in their 60s or older
  • men (except for some subtypes, such as follicular lymphoma, which are more common in women)
  • white people
  • those who have a parent, child, or sibling with NHL
  • those who have been exposed to some drugs, such as benzene, and some herbicides
  • those who have been exposed to radiation
  • those who have certain autoimmune diseases
  • those who have overweight or obesity (although more research is needed to confirm this)

Smoking is considered the strongest negative predictor of survival in people with cancer. Smoking after a cancer diagnosis is associated with:

  • increased treatment toxicity
  • higher risk of treatment failure
  • higher risk of a second cancer
  • lower quality of life

Chemicals in smoke may reduce your liver’s ability to metabolize chemicals in chemotherapy drugs and increase your risk of complications.

A 2019 review suggests that nicotine may impair the effectiveness of chemotherapy by activating pathways that stimulate cell growth and inhibiting programmed cell death.

Nicotine is also found in e-cigarette products. One 2024 study found that people who vaped and smoked cigarettes had a 4 times greater risk of lung cancer than those who only smoked cigarettes.

Some small studies have found that smoking cannabis may help treat nausea and vomiting caused by cancer chemotherapy.

In a 2020 study, researchers found that current smoking was associated with lower quality of life at diagnosis and at a 3-year follow-up in 2,805 lymphoma survivors.

A 2021 study in Ireland found that being a current smoker or an ex-smoker was associated with a less favorable NHL outcome. Compared with nonsmokers, smokers were 47% more likely to die within 5 years after an NHL diagnosis. In comparison, young patients and non-smokers had 5-year survival rates of 87.5% and 59%, respectively.

Continuing to smoke can also increase your risk of developing a secondary cancer.

Here are some questions people frequently ask about smoking and NHL.

Can secondhand smoke exposure increase your risk of non-Hodgkin’s lymphoma?

In a 2022 study in Australia, researchers found that the risk of follicular lymphoma (a subtype of non-Hodgkin’s lymphoma) increased with indoor exposure to more than two smokers during childhood but not during adulthood.

These results were consistent with previous studies that found that the risk tended to increase with total years and intensity of exposure.

Can smoking affect your immune system?

Substantial research suggests that smoking harms your immune system and makes your body less capable of fighting disease. Smoking also increases the risk of some autoimmune diseases, such as rheumatoid arthritis.

If I smoked before being diagnosed with NHL but stopped after diagnosis, will that affect my outlook?

People who quit smoking after a cancer diagnosis tend to live longer and have a better chance of successful treatment. They also have fewer treatment side effects than people who continue to smoke.

Can alcohol consumption increase your risk of non-Hodgkin’s lymphoma?

Research has found evidence that alcohol intake is associated with a decreased risk of follicular lymphoma, as well as a decreased risk of kidney cancers and non-Hodgkin’s lymphoma. However, the harms of drinking alcohol outweigh any potential benefits.

Smoking increases your risk of developing many types of cancer.

Researchers have found more evidence to support a connection between smoking and HL than between smoking and NHL. However, some studies suggest a link between smoking and an NHL subtype called follicular lymphoma. It’s not clear how strong this association is.

Quitting smoking after a cancer diagnosis can help improve the effectiveness of your treatment and improve your outlook.

Quitting can be difficult, but there are many resources available to help make it easier. Learn more about quitting smoking.