Does quitting smoking reduce abdominal aortic aneurysm risk?

01

First ask whether the research counts diagnoses or measures diameter

An AAA is an abnormal enlargement of the abdominal part of the body's main artery, not a cancer. Research on new AAA diagnoses follows people for the development of an aneurysm. Research on growth starts with people who already have one and compares changes in its size. A lower chance of a new diagnosis cannot tell you what happened to an aneurysm already seen on a scan.

The 2020 Surgeon General report judged the evidence sufficient that quitting reduces new AAA risk, with a greater reduction as time without smoking increases. A 2018 synthesis found that a modeled risk curve after about 25 years without smoking approached the never-smoking group. That is a population comparison, not a promise that your risk resets in year 25. Its studies differed substantially, and a modeled diagnosis-risk curve is not a diameter measurement.

[1][2][4]

02

What the newer growth review actually adds

In 2020 the report considered evidence for slowing an existing AAA's expansion suggestive, not sufficient. A review published in 2026 adds a synthesis of six longitudinal cohort studies. Its network analysis estimated that former smokers had, on average, 0.45 millimetres less AAA growth per year than current smokers; the 95% confidence interval was 0.06–0.83 millimetres less. This is the difference between group averages, not an instruction to subtract 0.45 millimetres from your own scan each year.

Less growth is not shrinkage: an aneurysm can still become larger while growing more slowly than another group's average. The review did not detect a clear difference between former and non-smokers, but this does not establish equivalence. It searched through January 2022 using data collected in 1987–2017, not new 2026 participants. Smoking definitions, measurements and follow-up varied, confounding remained possible, and quitting duration was unavailable. It cannot specify which week after quitting growth slows or predict one person's rupture risk.

[1][3]

03

A smoke-free date does not replace the next scan

AAAs often cause no symptoms. Feeling better after stopping cigarettes does not tell you their diameter. If an AAA has been diagnosed, the treating team uses imaging and the clinical situation to plan follow-up; this page does not choose scan intervals or surgery thresholds. Useful questions are: ‘What did the latest scan measure?’ and ‘Does my follow-up plan need changing?’ Quitting alone is not a reason to cancel a booked scan.

For quitting support in England, the NHS describes local stop-smoking services; elsewhere, use your local health service. A cessation appointment and aneurysm follow-up serve different purposes. Discuss new or changing concerns with the team responsible for your care; more smoke-free days cannot establish that an aneurysm concern has resolved. This page does not assess symptoms or ask you to enter a scan result or smoking history.

[4][5]

04

What to keep in mind

• New AAA risk and existing AAA growth are different outcomes.
• The 2026 growth estimate is a group difference, not a shrinkage forecast.
• Keep aneurysm follow-up separate from quitting support.