A pilonidal sinus is a small channel or pit in the skin, usually in the fold between the buttocks near the tailbone. It often contains hair and skin debris and can become infected. It is more common in young adults, people with thick body hair and people who sit for long hours, such as drivers and office workers.
Common symptoms
- A small pit or dimple at the top of the buttock crease
- Pain or tenderness near the tailbone, especially when sitting
- Swelling and redness (a pilonidal abscess)
- Discharge of pus or blood, sometimes with a bad smell
- Hair visible in the opening
- Fever in some cases of infection
Why does it form?
Loose hairs can be pushed into the skin of the buttock fold by friction, sitting and sweating. The body reacts to the hair like a foreign object and a small tract forms, which can collect debris and get infected.
Why can a pilonidal sinus come back?
Pilonidal sinus is known to recur in some people even after treatment. Reasons can include small side tracts that remain, the shape of the buttock fold, hair continuing to enter the area, and wound healing factors. Your surgeon will explain the risk for the method chosen. No treatment can promise that it will never return.
How is it diagnosed?
Diagnosis is made by a surgeon examining the area.
How is treatment decided?
Treatment is decided after examination by the surgeon. Learn more on our pilonidal sinus treatment in Kompally, Hyderabad page.
Habits that may help after treatment
- Keep the area clean and dry
- Follow hair removal advice from your surgeon
- Take breaks from long sitting
- Attend follow-up visits for wound checks
When to seek prompt care
Rapidly increasing pain, spreading redness, high fever or feeling unwell need prompt medical attention.
Pain near the anus rather than the tailbone may be a different condition; see piles and fistula.
Frequently asked questions
Where does a pilonidal sinus occur?
It usually occurs in the fold between the buttocks, near the tailbone.
Is pilonidal sinus related to piles or fistula?
No. It occurs near the tailbone, not at the anus, although people sometimes confuse them.
Why does a pilonidal sinus come back?
It can recur in some people because of small side tracts, the shape of the buttock fold, hair entering the area again and wound healing factors. Your surgeon will explain the risk for the method chosen.
Medical disclaimer
This article is for general information only and is not medical advice. Diagnosis and treatment depend on an in-person examination by a registered medical practitioner. In an emergency, go to the nearest emergency department.
Sree Nandaka Advanced Surgery Hospital, Kompally (near Ruby Block), Hyderabad. Call Us: 90008 61000.
Medically reviewed by Dr. Praveen Koduru, MBBS, MS (General Surgery), Telangana State Medical Council Reg. No. 45306
Concerned About a Pilonidal Sinus?
If you have pain, swelling or discharge near the tailbone, call our surgical team in Kompally for an examination.
Call Us