A 2021 patient survey published in the British Journal of Dermatology (Thompson et al.) identified the most commonly reported HS flare triggers as stress, high-sugar and high-carbohydrate foods, exercise, weight gain, smoking, and hormonal changes around the menstrual cycle. Not everyone has the same triggers, and most people with HS have more than one.
Why do HS flares happen?
HS is an autoinflammatory condition rooted in follicular occlusion and immune dysregulation. A blocked hair follicle signals to the immune system that the follicle is damaged. The immune system responds with inflammation, and in HS, that response is dysregulated: disproportionate, persistent, and difficult to turn off.
Triggers don't cause HS to develop. They act on a system that is already primed to respond. That distinction matters, because it means trigger avoidance doesn't address the underlying condition. It reduces the load on a system that's already under strain.
Understanding your personal triggers is useful. But no single lifestyle change will put HS into remission on its own.
Hormonal changes
Hormonal fluctuations are one of the most consistently reported HS triggers, particularly for women. Studies show that between 43% and 77% of women with HS experience worsening symptoms in the days before or during their period.
The mechanism involves androgens. Sex hormone levels fluctuate through the menstrual cycle, and HS appears to be sensitive to androgen activity specifically. This is part of why HS is more common in women, tends to appear after puberty, and often improves after menopause. It also explains why anti-androgen medications like spironolactone are used as an HS management option.
Women with PCOS, which involves elevated androgen levels, are 2.14 times more likely to have HS than those without it.
Stress
Stress is a well-reported trigger across patient surveys and clinician observations. The mechanism is the stress-inflammation axis: psychological and physical stress activates the hypothalamic-pituitary-adrenal (HPA) axis, releasing cortisol and inflammatory cytokines. In HS, where inflammatory signalling is already dysregulated, this additional inflammatory load can be enough to initiate or worsen a flare.
Physical stress includes illness, infection, surgery, and injury. Emotional stress includes work pressure, relationship strain, and the psychological burden of living with HS itself. That last point creates a compounding cycle: HS causes stress, and stress worsens HS.
Diet and specific food triggers
Diet is the most discussed trigger category in HS communities, and the evidence is mixed but directionally consistent. A 2019 review in the International Journal of Dermatology (Silfvast-Kaiser et al.) noted that low glycaemic index eating patterns, dairy reduction, and alcohol reduction appeared to benefit some patients. No specific diet has been proven to treat HS, and individual responses vary significantly.
The most commonly reported food triggers include refined sugar and high-glycaemic carbohydrates, dairy products, brewer's yeast (found in beer and some breads), nightshades (tomatoes, potatoes, peppers) in some individuals, and alcohol.
The honest takeaway is that dietary triggers are highly individual. Keeping a detailed food and symptom diary is the most practical way to identify your personal pattern.
For more on this, see our guide to diet and HS flare triggers (add URL when Post #24 publishes)
Friction, heat, and mechanical irritation
Physical irritation of HS-prone skin is a direct and well-established trigger. Friction from tight clothing, skin-on-skin contact in body folds, and shaving can all contribute to follicular blockage and the inflammatory cascade that follows.
Heat and sweating compound the problem. HS symptoms are reported as worse in summer and in humid environments by a significant portion of patients. Practical steps include wearing loose, breathable fabrics, avoiding shaving inflamed areas, and keeping high-friction zones as cool and dry as possible during a flare.
Smoking
Smoking is the most consistently documented modifiable risk factor for HS severity and treatment outcomes. A large US population study (British Journal of Dermatology, 2018) found that HS incidence was 0.20% among smokers vs 0.11% among non-smokers. Smokers also develop HS in more body areas, experience more severe disease, and respond less well to treatment.
A 2026 study (Poulsen et al., JEADV) in a cohort of 787 HS patients found that current smokers were significantly more likely to be at Hurley Stage III. Among patients on tetracycline antibiotics, smokers had roughly half the clinical response of non-smokers.
A large South Korean cohort study (HS Foundation, 2025) found that the risk reduction from smoking cessation only becomes apparent after approximately three years of remaining smoke-free.
Weight and body composition
Body weight is listed as a trigger and a risk factor for HS, but it requires careful framing. Excess weight does not cause HS. People of all body sizes develop HS. But obesity is associated with increased inflammation systemically, and excess tissue in body folds creates more friction and occlusion in HS-prone areas.
Managing metabolic health through diet and movement, where possible, is worth discussing with a clinician. But weight loss is not a treatment for HS.
Why triggers vary so much between people
HS is a condition with a significant individual component. Genetics, immune profile, hormonal patterns, microbiome composition, and lifestyle factors all interact. What consistently triggers a flare in one person may have no effect on another.
For a deeper look at how HS inflammation works, see our guide to the connection between HS and inflammation (add URL once Post #8 is live)
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Frequently asked questions
Can stress alone trigger an HS flare?
Yes, in some people. Stress activates inflammatory signalling pathways that can worsen HS. The stress-HS relationship also works in reverse: living with HS is itself a source of significant psychological stress, which can create a compounding cycle.
Is sugar a proven trigger for HS?
High-glycaemic diets have been associated with worsened HS symptoms in some small studies. The evidence is not definitive. Reducing refined sugar as part of a generally anti-inflammatory diet is a reasonable approach, but it should be seen as one input among several, not a cure.
Does quitting smoking improve HS?
Evidence suggests it does, but not immediately. A large cohort study found that the risk reduction from quitting smoking takes approximately three years to become apparent. Smokers with HS also respond less well to antibiotic treatment.
Do hormones trigger HS flares in women?
Yes. Between 43% and 77% of women with HS report worsening symptoms around their menstrual period. Hormonal treatments including combined oral contraceptives and spironolactone are used to manage hormone-related flares in clinical practice.
Can you prevent HS flares entirely?
Not reliably. HS is a complex inflammatory condition, and flares can occur even with careful trigger management. Identifying and reducing your personal triggers can lower frequency or severity, but complete prevention is not a realistic expectation for most people.
This article is for educational purposes only. It is not a substitute for medical advice. If you have hidradenitis suppurativa, work with a board-certified dermatologist to build a treatment plan.
References
- Thompson AM, Fernandez JM, Rick J, et al. Identifying triggers for hidradenitis suppurativa flare: a patient survey. Br J Dermatol. 2021;185(1):225-226. https://doi.org/10.1111/bjd.19926
- Silfvast-Kaiser A, Youssef R, Paek SY. Diet in hidradenitis suppurativa: a review of published and lay literature. Int J Dermatol. 2019;58(11):1225-1230. https://doi.org/10.1111/ijd.14465
- Garg A, et al. Sex- and age-adjusted population analysis of prevalence estimates for HS in the United States. Br J Dermatol. 2018;178(3):709-714. https://doi.org/10.1111/bjd.15939
- Poulsen AH, et al. Impact of smoking on disease severity and treatment outcomes in HS. J Eur Acad Dermatol Venereol. 2026. PMID: 41623198
- HS Foundation. Can quitting smoking lower the risk of hidradenitis suppurativa? September 2025. https://www.hs-foundation.org/can-quitting-smoking-lower-the-risk-of-hidradenitis-suppurativa
Published by HS Daily.
