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what causes hs

Hidradenitis suppurativa (HS) is thought to be caused by a mix of genetics, immune system overactivity, and problems in hair follicles—not by poor hygiene or anything you “did wrong.”

Quick Scoop: What Causes HS?

Most experts now see HS as a chronic inflammatory disease of the hair follicles in areas where skin rubs together (like armpits, groin, under breasts, buttocks).

Key points in plain language:

  • HS starts when hair follicles get blocked, weaken, and rupture under the skin.
  • The immune system overreacts to this damage, causing deep inflammation, painful lumps, and tunnels (sinus tracts).
  • Genetics play a role: HS often runs in families, suggesting inherited changes in how follicles and inflammation are regulated.
  • It is not an infection you “caught,” not an STD, and not caused by being “unclean.”

Main Underlying Causes

Think of HS as several risk factors lining up, rather than one single cause.

  • Follicular occlusion (blockage of hair follicles) : The starting point in HS is usually plugging of hair follicles in areas with apocrine glands (sweat glands) and friction.
  • Immune system dysregulation : HS is associated with abnormal inflammatory pathways (for example, overexpression of inflammatory cytokines) that keep the inflammation going even after the initial blockage.
  • Genetic factors : A noticeable subset of people with HS have family members with the same condition, supporting a hereditary component and, in some cases, specific gene variants affecting follicle structure and inflammation.

These factors together create a cycle: follicle blockage → rupture → inflammation → tissue damage and scarring → new lesions nearby.

Triggers and Risk Factors (They Don’t “Cause” HS, But Can Worsen It)

HS triggers are things that can flare an underlying condition, not original causes.

Commonly discussed risk factors and triggers:

  • Mechanical friction : Tight clothing, chafing in folds (thighs, under breasts, armpits) may irritate follicles and worsen existing HS.
  • Smoking : Strongly associated with HS; nicotine and related changes likely worsen inflammation and follicular plugging.
  • Weight and metabolic factors : Extra weight can increase skin friction and is associated with more severe HS, though thin people can absolutely have HS too.
  • Hormonal influences : HS often starts around puberty and may flare with menstrual cycles, suggesting hormones modulate disease activity.
  • Heat and sweating : Warm weather, heavy sweating, and stress on sweat glands can aggravate existing lesions for some people.
  • Comorbid conditions : HS is more common with certain other inflammatory diseases (like inflammatory bowel disease), supporting its immune-based nature.

An example: a person with a genetic predisposition and overactive inflammatory pathways might stay mild for years—then weight gain, smoking, or intense friction areas can push them into frequent, painful flares.

Myths vs Reality Around “What Causes HS”

Because HS shows up as painful boils and drainage, people often get hit with stigmatizing myths.

Common myths (and what we know):

  • “HS is caused by being dirty.”
    • Reality: HS is driven by follicle blockage and immune dysregulation; showering more or “scrubbing harder” won’t prevent it.
  • “It’s just bad shaving or ingrown hairs.”
    • Reality: Ingrown hairs can irritate skin, but HS is a deeper, chronic inflammatory disease, not just shaving gone wrong.
  • “You must have done something to cause this (like sex, an STD, or poor lifestyle).”
    • Reality: HS is not an STD and not a simple lifestyle disease; while smoking and weight can worsen it, many non-smokers and people at all sizes have HS.
  • “If you lost weight / quit smoking, HS would disappear.”
    • Reality: Lifestyle changes can reduce flares and improve severity, but they rarely “cure” HS because underlying immune and follicular factors remain.

Why This Matters If You Have HS

Understanding causes can change the emotional story you tell yourself:

  • HS is not your fault ; you did not “cause” it through laziness or poor self-care.
  • There are modifiable factors (like smoking, friction, and sometimes weight) that you can work on to reduce flare-ups, often alongside medical treatment.
  • Early diagnosis and treatment can help break the inflammation–scarring cycle and protect quality of life.

If you’re seeing painful, recurring lumps or boils in typical HS areas, a dermatologist or experienced primary care clinician can help confirm the diagnosis and discuss treatment options.

TL;DR: HS happens when genetically and immunologically vulnerable hair follicles in friction areas get blocked and rupture, triggering chronic inflammation; things like smoking, friction, hormones, and weight can worsen it, but it is not caused by poor hygiene or being “dirty.”

Information gathered from public forums or data available on the internet and portrayed here.