Smoking and hidradenitis suppurativa: the strongest signal in the list

Observational evidence · moderate certainty

What the studies actually found

A 2024 meta-analysis pooling 23 studies found smoking associated with HS at an odds ratio of 3.10: roughly, smokers were three times more likely to have HS than non-smokers across the pooled data. The heterogeneity between studies was very high, which the authors flag clearly, but the direction of the association is consistent.

The most impressive single dataset is a Korean national cohort of 6.2 million people: compared with people who kept smoking, the risk of developing new HS was lower in recent quitters (adjusted hazard ratio 0.68) and lowest in never-smokers (0.57), with the benefit of quitting emerging after about 3-4 years. And a 1,689-person HS cohort found a dose-response pattern: more pack-years, more affected body sites, more pain, worse quality of life.

What we don't know

All of this is epidemiology, not a randomized trial, and nobody will ever randomize people to smoke. The sharpest open question is about people who already have HS: the data on developing HS and on severity are strong, while direct evidence that quitting improves an HS that already exists is thinner. The cohort data suggest the body needs years, not weeks, to show the difference.

Context, not a lecture

If you smoke and have HS, you already know the general health case for stopping; this page adds the HS-specific numbers to that file. Quitting is famously hard and famously personal: what worked for others (support programs, medication-assisted approaches, cold turkey) is a conversation for you and your doctor, not something a website assigns you. What I'd take from the evidence is patience: if you quit, the data say the payoff builds over years, so an unchanged month is not proof it was pointless.