This article is for information purposes only; it is not a substitute for an examination and a physician’s assessment.
Pilonidal sinus is a disease of tunnels and cavities formed by hairs burrowing under the skin in the cleft at the tailbone. It has three faces: silent pits, a painful abscess, and a discharging chronic sinus. It is most common in young men. The silent stage can be observed; an abscess needs drainage; in chronic disease the lasting solution is procedural — in suitable cases, incision-free laser treatment as a day procedure.
The folk name for this condition is one of the most misleading ever coined — as if a single hair had flipped around and were wandering beneath the skin. The reality is simpler and less frightening: hairs shed into the cleft at the tailbone pierce the skin, and the skin builds a system of cavities and tunnels against this foreign guest. The medical name is pilonidal sinus; its Latin roots translate literally as "nest of hair." Two words are enough to understand the disease: hair and nest.
Cyst, abscess, or sinus? Clearing up the terms
Patients hear three words used interchangeably; let's separate them. The sinus is the small opening(s) in the skin and the tunnel beneath — the disease's permanent infrastructure. The abscess is that infrastructure filling with pus and swelling — the painful, acute event. The popular "cyst" is usually just the name for the palpable fullness; technically, there is no true cyst. In other words, we are describing three different days of the same disease: the quiet infrastructure, the full infrastructure, and the burst infrastructure.
Who gets it, and where?
The typical profile is a man aged 15-30 with dark, coarse hair; those who sit for long hours, those who are overweight, and those with a family history stand out. The location is almost always the same: the cleft at the tailbone. Rarely it appears in the navel and — as barber's disease — between the fingers. The causes are detailed in the causes article.
How does it show itself?
Three pictures: silent pits noticed in the cleft (usually by chance); an abscess that swells over a few days, throbs, and makes sitting impossible; and an intermittent discharge that stains the underwear. I covered all the symptoms, and which ones are urgent, in the symptoms article. Let me also add that tailbone pain is not always pilonidal sinus — for the differential diagnosis, see this guide.
Diagnosis: almost always by sight
In most patients the diagnosis is made in the examination room within seconds — the typical pits in the cleft are the disease's signature. Imaging (ultrasound, rarely MRI) is needed only in cases whose extent is unclear, that have recurred, or that are atypical. In other words, what gets postponed out of "fear of the examination" is actually the shortest step.
Treatment: according to the stage
For silent pits, the approach is strategy rather than treatment: hair removal, moisture and pressure management, observation. For an abscess there is only one right answer: drainage — a small procedure that takes minutes and brings instant relief. For the chronic sinus, a lasting solution is discussed, and here the era has changed: in suitable cases, the classic "cut wide and leave open" surgery has given way to incision-free laser closure — day surgery, no stitches, on your feet the next day. A comparison of the methods is on the treatment page.
Frequently asked questions
Does pilonidal sinus turn into cancer?
In practice, no — exceptional transformations have been reported only in chronic cases neglected for decades. The present-day risk is not cancer but abscess flare-ups and branching of the tunnel.
Does it occur in women too?
Yes; it is less common than in men but not rare. The treatment approach is the same.
Do my silent pits require surgery?
The current approach to symptom-free pits is observation — together with preventive measures. The uncertainty of "will it cause trouble someday?" does not justify preventive surgery.
What happens if I don't get treated?
It may stay silent, or it may enter the abscess-discharge cycle and expand its network of tunnels. One thing is certain: chronic disease does not heal on its own, and the longer you wait, the larger the procedure becomes.
References
- American Society of Colon and Rectal Surgeons (ASCRS) — Clinical Practice Guidelines for Pilonidal Disease, fascrs.org
- NHS — Pilonidal sinus, nhs.uk
- Turkish Society of Colon and Rectal Surgery, tkrcd.org.tr
Let's put a clear name on that "thing" at your tailbone: 444 8 623 — Levent.
Content owner: Yasir Gozu, MD
Published: May 9, 2024
Last updated: July 8, 2026
