You may notice that your HS symptoms follow certain patterns, such as after exercising in hot weather, wearing tight clothing or around your period. You should know that smoking is strongly associated with HS, but it is not proven to act as an immediate trigger for every flare.
You and your dermatologist can look at which factors genuinely affect your skin. Smoking, higher body weight, hormones, friction, heat and sweating may influence symptoms differently, so understanding your own triggers can help you focus on what matters for you.
What Does an HS Flare Actually Mean?
You may notice an HS flare when a new painful lump appears or when existing swelling, tenderness or drainage suddenly worsens. You may also feel itching or discomfort before much is visible on your skin.
You should know that a flare does not mean you have done something wrong. You and your dermatologist can look at possible triggers, but not every flare has an obvious cause, so you do not need to blame yourself for every new lesion.
What Causes HS and What Triggers a Flare?
You should know that a cause and a trigger are not the same thing. HS is thought to involve hair follicle blockage and rupture, immune inflammation, genetic susceptibility and hormonal influences, while possible aggravating factors may make your symptoms worse.
You may notice that friction, heat or hormonal changes seem to bring on your flares, but you should not assume that you have caused your HS. You and your dermatologist can focus on your own pattern and identify which factors genuinely seem to affect you.
How Can Friction Aggravate HS?
You may notice that friction makes your HS more uncomfortable, especially in your armpits, groin, inner thighs or beneath your breasts. Tight clothing, long walks or exercise may increase rubbing around areas that are already inflamed.
You do not need to stop moving because of this. You and your dermatologist can see whether reducing unnecessary rubbing helps your symptoms and whether friction seems to be one of your personal aggravating factors.
Can Tight Clothing Make HS Worse?
You may notice that tight clothing makes your HS more uncomfortable, especially around your groin, inner thighs, buttocks or underarms. You may find that tight underwear, gym clothes or trousers increase pressure and rubbing during a flare.
You do not need to change all your clothes. You can notice which clothes make your symptoms worse and choose looser options when needed. You should know that clothing does not cause HS, but it may aggravate your symptoms.
How Are HS Risk Factors Different From Things That May Worsen Flares?
| Factor | What the evidence suggests | How to interpret it |
| Smoking | Strongly associated with HS; evidence on disease severity is mixed | Important risk factor; not necessarily an immediate trigger for every flare |
| Higher body weight | Associated with HS and greater disease severity in some people | Disease modifier rather than a simple day-to-day trigger |
| Heat and sweating | Commonly reported aggravating factors | May worsen symptoms, moisture and friction |
| Friction and tight clothing | Mechanical stress can aggravate affected skin | May worsen existing or developing lesions |
| Menstrual cycle | Perimenstrual flares are reported by some women | Individual pattern varies |
| Stress | Commonly reported alongside flares | Evidence that stress directly aggravates HS flares is less certain. |
| Diet | Certain foods are being studied | No single universally proven HS diet |
| Hair removal | May cause local irritation | Evidence for direct triggering is limited |
Can Heat Make HS Symptoms Worse?
You may notice that heat makes your HS symptoms worse, especially when you sweat more and your skin stays warm and damp. You may find flares become more uncomfortable during hot weather or after spending time in a warm environment.
You do not need to avoid heat completely. You can take breaks in cooler places and change out of damp clothes when possible. You should know that heat does not cause HS, but it may aggravate your symptoms.
Evidence Note
Not all factors you may think of as HS ‘triggers’ have the same level of evidence. Smoking and higher body weight have stronger evidence as factors associated with HS, while higher body weight is also linked with greater disease severity in some studies. Heat, sweating, friction, stress, diet and menstrual changes are often identified through patient reported or observational research. If you notice that something precedes your flare, that does not necessarily prove it caused your symptoms.
Can Sweating Make Hidradenitis Suppurativa Worse?
You may notice that sweating makes your HS more uncomfortable, especially after exercise or during hot weather. You should know that sweating does not cause HS, but prolonged moisture can increase chafing and irritation in your groin or underarms.
You can change into dry clothes and choose breathable fabrics when possible. You should avoid aggressively scrubbing your skin, as you may irritate it further. These measures may help reduce moisture and friction while protecting your skin barrier.
How Is Smoking Linked to HS?
You should know that smoking is strongly associated with HS. If you smoke, this association is important for your overall HS care, although evidence that smoking directly worsens disease severity or triggers individual flares is less certain.
You should not assume that smoking alone caused your HS, as HS can also affect people who do not smoke. If you smoke, you and your healthcare team can discuss support to help you stop. Smoking cessation is recommended for its overall health benefits and may also benefit HS, although its effect on individual flare frequency is not fully established.
Can Body Weight Affect HS Symptoms?
You should know that HS can affect you at any body size, and having a higher body weight does not mean you caused your condition. You may also develop HS even if you are slim.
You may find that higher body weight is linked with more HS symptoms in some people, possibly because of friction and inflammation. You and your healthcare team can discuss weight management when it is appropriate for your overall health, but you should still receive proper HS treatment regardless of your body size.
UK Guidance Note
The British Association of Dermatologists’ March 2025 guidance says HS can affect people of normal weight but is more common in people who are overweight or obese. If you smoke, it recommends stopping, and it advises you to avoid tight clothing and shaving your affected areas. These steps can support your self management but should not replace appropriate medical treatment.
Can Hormonal Changes Trigger HS Flares?
You may notice that your HS symptoms become worse around certain hormonal changes, especially before your period. This pattern is not the same for everyone, and some people may notice no clear connection with their menstrual cycle.
You can keep a record of your periods and HS flares if you menstruate. You and your dermatologist can use this information to see whether hormonal changes seem to influence your symptoms, without assuming that your hormones alone cause HS.
Why Do Some People Flare Before Their Period?
You may notice your HS becomes more painful or active in the days before your period. You may see new painful lumps or notice existing lesions becoming more uncomfortable, although this pattern is different for everyone.
You can track your HS symptoms across several menstrual cycles to see whether the pattern repeats. You and your dermatologist can use this information to understand whether hormonal changes may be affecting your flares, while remembering that stress, heat or friction may also play a role.
Can Pregnancy or Menopause Change HS Activity?
Your HS symptoms may change during pregnancy, after giving birth or around menopause, although the pattern is different for everyone. You can discuss any changes with your healthcare professional rather than assuming that hormones are the only cause.
- During pregnancy: Your HS activity may change as your hormone levels change.
- After giving birth: You may notice your symptoms change during the postnatal period.
- Around menopause: Hormonal changes may affect HS activity in some people.
- With hormonal contraception: Some people report changes in HS symptoms with hormonal contraception, but the effect can vary between individuals.
These changes do not necessarily mean that hormones are causing your HS. You and your doctor can review the timing of your symptoms and treatment together.
Can Stress Trigger an HS Flare?
You may notice your HS symptoms change during stressful periods, but you should know that stress does not necessarily cause HS flares. Living with pain, drainage and repeated symptoms can also make you feel more stressed, creating a difficult cycle.
You can keep track of stress and your HS flares to see whether you notice a consistent pattern. You should not blame yourself when a flare happens, and you can tell your healthcare team if HS is affecting your sleep, work, relationships or emotional wellbeing.
Clinical Tip
When you track possible triggers, record the date of each flare, the affected area, your pain or drainage, heat and sweating, your clothing or exercise, menstrual timing if relevant, your stress levels, foods, smoking and recent changes in your medicines or skincare. Looking for repeated patterns in your own record is more useful than assuming one event caused a flare.
Can Shaving or Hair Removal Trigger HS?
You may notice that shaving or waxing makes your HS prone skin more irritated. Shaving can cause small cuts or follicular irritation, while waxing may create more mechanical trauma.
You should know that hair removal does not cause HS, but it may aggravate your symptoms. You can avoid shaving over painful lumps or open lesions and discuss your hair removal routine with your dermatologist if you notice repeated flares afterwards.
Are Food and Diet Proven HS Triggers?
You may notice that certain foods seem to coincide with your HS flares, but you should know that there is no single proven HS diet that works for everyone. Dairy and highly processed or high glycaemic foods are being studied, but the evidence is still developing.
You can keep a simple food and symptom record if you suspect a pattern. You should avoid removing several food groups at once, and you can speak with your GP or dietitian before making major dietary changes so your nutrition stays balanced.
How Can You Work Out Your Own HS Triggers?
You may find symptom tracking useful because your HS triggers can differ from someone else’s. You can simply note when a flare starts, where it occurs, how painful it is and what happened in the days before it.
You may notice patterns linked with heat, exercise, your period or tight clothing. You and your dermatologist can look for repeated patterns over time, and photos from active flares can also help explain what happens when your skin looks clearer during an appointment.
Research Insight
Recent research has examined factors people report as worsening HS. These studies can help you discuss your own patterns, but because many are observational or self reported, they cannot prove that a particular factor caused your flare. Tracking your symptoms over time can help you and your dermatologist discuss possible aggravating factors.
When Should You Speak to a Dermatologist About Frequent Flares?
You do not need to identify every HS trigger before seeking medical advice. You should consider a dermatology review if your flares keep returning, cause significant pain, drainage or scarring, or interfere with your daily life.
You can tell your dermatologist about patterns you notice with smoking, periods, heat, friction or weight changes, and bring photos from previous flares. You should seek prompt medical attention if a lesion becomes rapidly more swollen or painful, redness spreads, or you feel feverish or unwell.
Myth vs Fact
| Myth | Fact |
| Every HS flare has an identifiable trigger. | Some flares occur without an obvious trigger. |
| Smoking is the sole cause of HS. | Smoking is strongly associated with HS, but people who do not smoke can also develop HS. |
| Higher body weight means you caused your HS. | HS can affect people of any body size. |
| Heat and sweating cause HS. | Heat and sweating may aggravate symptoms in some people, but they are not established causes of HS. |
| Stress definitely causes HS flares. | Stress is commonly reported alongside flares, but the causal relationship is not fully established. |
| There is one diet everyone with HS should follow. | There is no single universally proven HS diet. |
| If a flare happens after eating a food, that food definitely caused it. | A repeated pattern may be worth discussing, but one episode does not prove causation. |
| You should stop exercising if exercise seems to worsen HS. | You may be able to modify activity, reduce overheating and friction, and choose activities that are more comfortable. |
Key Takeaways
- An HS flare means a new or substantial worsening of your HS signs or symptoms.
- Flares do not always have an obvious trigger, and a trigger is not necessarily the cause of HS.
- Friction, tight clothing, heat and sweating may aggravate symptoms in some people.
- Smoking is strongly associated with HS, while evidence on its relationship with disease severity is mixed. Higher body weight is associated with HS and has been linked with greater disease severity in some studies.
- Hormonal changes, particularly around menstruation, may affect HS activity in some people.
- Stress and certain foods may appear to coincide with flares, but the evidence is less established.
- Shaving or waxing may irritate HS prone skin, although evidence that hair removal directly causes HS is limited.
- There is no single universally proven HS diet.
- Keeping a symptom and trigger diary can help you identify repeated patterns and discuss them with your dermatologist.
- Frequent, painful, draining or scarring flares may require medical review and adjustment of your HS treatment.
Frequently Asked Questions
1. Does an HS Flare Mean Your Treatment Has Stopped Working?
No. You can have a flare even when your overall treatment is helping. If your flares become more frequent, painful or draining, tell your dermatologist so they can review your treatment and decide whether your plan needs adjusting.
2. How Long Should You Track a Possible HS Trigger?
Record your symptoms over several weeks or months rather than judging one episode. If you repeatedly notice the same pattern before your flares, show your diary to your dermatologist so you can discuss whether it is likely to be relevant.
3. Should You Stop Exercising If Exercise Seems to Aggravate HS?
Not necessarily. You may be able to continue exercising by reducing rubbing, overheating and prolonged dampness. If your symptoms repeatedly worsen with one activity, you can adjust your clothing or routine and discuss your pattern with your dermatologist.
4. What Can You Do During a Hot Weather HS Flare?
You can try to keep your skin cool and dry, change out of damp clothing and reduce unnecessary friction. If your flare becomes rapidly more swollen or painful, or you feel unwell, contact your healthcare team for advice.
5. Can Losing Weight Cure HS?
No. If you have a higher body weight, weight management may improve your overall health and may help your HS symptoms, but it does not guarantee that your HS will clear. You should still receive appropriate medical treatment for your HS.
6. Can Hormonal Contraception Affect Your HS?
Some people notice changes in their HS with hormonal contraception, but the effect varies. If you notice a repeated change after starting or stopping contraception, record your symptoms and discuss your pattern with your doctor before changing your contraception.
7. Is It Safe to Shave or Wax When You Have HS?
Hair removal can irritate your HS prone skin, particularly during a flare. You may want to avoid shaving or waxing over painful lumps or open areas. If you repeatedly notice problems after hair removal, discuss your routine with your dermatologist.
8. Should You Cut Out Foods If You Suspect a Dietary Trigger?
Not immediately. You can keep a simple food and symptom diary first to see whether your pattern repeats. Avoid removing several food groups on your own; if you want major dietary changes, discuss your plan with your GP or a dietitian.
9. When Does an HS Flare Need Prompt Medical Attention?
Seek prompt advice if your lesion becomes rapidly more swollen or painful, redness spreads, or you feel feverish or unwell. You should also contact your healthcare team if your pain, drainage or scarring becomes difficult for you to manage.
10. What Should You Bring to a Dermatology Appointment About Your Flares?
Bring your symptom diary, photos of active flares and notes about your pain, drainage, menstrual timing, smoking, clothing, heat or other patterns you have noticed. This can help you and your dermatologist decide which factors are worth focusing on.
Final Thoughts: What Triggers Hidradenitis Suppurativa Flares?
HS symptoms may be aggravated by factors such as friction, heat, sweating and hormonal changes, while smoking and higher body weight are associated with HS and may influence overall disease burden. By tracking when your symptoms worsen and looking for repeated patterns, you and your dermatologist can identify possible aggravating factors without assuming that you caused the flare.
If you’re looking for a dermatologist in London, you can contact London Dermatology Centre for specialist assessment and advice.
References:
- Rosi, E. et al. (2022) ‘Hidradenitis suppurativa: the influence of gender, the importance of trigger factors and the implications for patient habits’, Biomedicines, 10(11), article 2973. Available at: https://www.mdpi.com/2227-9059/10/11/2973
- Shams, R.B. and Sayed, C.J. (2024) ‘Patient-reported exacerbating factors for hidradenitis suppurativa: A cross sectional study’, Journal of the American Academy of Dermatology, 91(2), pp. 333–336. Available at: https://pubmed.ncbi.nlm.nih.gov/38556091/
- Elzawawi, K.E. et al. (2024) ‘Hidradenitis suppurativa and its association with obesity, smoking, and diabetes mellitus: a systematic review and meta-analysis’, International Wound Journal, 21(9), article e70035. Available at: https://pmc.ncbi.nlm.nih.gov/articles/PMC11393007/
- Nielsen, V.W., Thomsen, S.F. and Naik, H.B. (2024) ‘Hidradenitis suppurativa pathogenesis: extrinsic factors’, Journal of the American Academy of Dermatology, 91(6S), pp. S17–S21. Available at: https://www.sciencedirect.com/science/article/pii/S0190962224027580
- Wolk, K., Join-Lambert, O. and Sabat, R. (2020) ‘Aetiology and pathogenesis of hidradenitis suppurativa’, British Journal of Dermatology, 183(6), pp. 999–1010. Available at: https://academic.oup.com/bjd/article/183/6/999/6600340