Understanding the right words to use can help guide your conversation about hidradenitis suppurativa (HS) with a dermatologist.

Abscess: a swollen area within body tissue, characterized by a painful, swollen lump that's filled with pus.

Blackhead: a dark plug of oil from skin in a hair follicle that has been exposed to oxygen. Blackheads appear in small pitted areas of skin, often appearing in pairs.

Bump: a swelling of the skin. Some bumps get bigger, break open, and drain pus with an odor.

Boil: an inflamed, pus-filled swelling on the skin, typically caused by the infection of a hair follicle.

Comorbidities: the presence of 2 or more medical conditions in a patient at the same time. For HS, these medical conditions may include metabolic syndrome, axial spondyloarthritis, Crohn's disease, ulcerative colitis, depression, anxiety, and polycystic ovary syndrome.

Cyst: a sac-like pocket that contains fluid, air, or other substances. Cysts can grow almost anywhere in your body or under your skin.

Flare: a sudden outburst or worsening condition.

Hidradenitis suppurativa (HS): a condition that causes small, painful bumps, which are called inflammatory nodules, to form under the skin. The bumps usually develop in areas where skin rubs together, such as the armpits, groin, buttocks, and breasts. The bumps heal slowly, recur, and can lead to tunnels under the skin and scarring.

Hurley stages: alternate name for the 3 stages of HS used by dermatologists.

  • Mild: also called Hurley stage I. Typically shows up as 1 or multiple bumps (inflammatory nodules) and abscesses with no scarring or tunnel (sinus tract) formation.
  • Moderate: also called Hurley stage II. Typically shows up as multiple abscesses along with limited tunnels and/or scarring.
  • Severe: also called Hurley stage III. Typically shows up as multiple or extensive interconnected tunnels, abscesses, and scarring.

Immune system: a complex network of cells and proteins that defends the body against infection.

Ingrown hair: an ingrown hair occurs when a shaved or tweezed hair grows back into the skin. It can cause inflammation, pain, and tiny bumps in the area where the hair was removed.

Lesion: a region in an organ or tissue that has suffered damage through injury or disease, such as a wound, ulcer, abscess, or tumor.

Nodule: a bump or small inflammatory swelling made up of abnormal cells in the body.

Scarring: a mark left on the skin after a surface injury or wound has healed.

Sinus tracts: (see Tunnels)

Sores: sores can form in areas of the body where the skin rubs together, like the groin, the armpits, and under the breasts.

Systemic: something that affects multiple organs or parts of the body, possibly affecting the entire body.

Tunnels (also called sinus tracts): over time, tunnels might form under the skin, connecting the sores. These wounds heal very slowly, if at all, and drain blood and pus. When the walls of an inflamed hair follicle rupture, pus leaking beneath the skin may form a narrow opening or passageway extending from the wound underneath the skin, forming a connection between sores (abscesses).