A pilonidal cyst is a pocket that forms in the skin at the top of the buttock crease, right over the tailbone. It fills with hair, dead skin cells, and other debris, and it can become infected, swollen, and painful. The condition affects roughly 26 per 100,000 people each year, most often young men in their late teens and early twenties.
How a Pilonidal Cyst Forms
For a long time, doctors believed loose hairs drilled into the skin like splinters. That theory has been replaced. Pilonidal disease is now understood as an acquired condition that starts with ordinary hair follicles stretching out and getting blocked.
The mechanics are straightforward. When you stand up, gravity pulls the tissue in the buttock midline downward while your body moves upward. Slouching while seated adds to that force. Over time, this repeated stretching widens the pores along the crease. Those widened pores collect dead skin cells, sweat, lint, and loose hair. The buildup blocks the follicle, trapping the natural oils your skin produces. The follicle swells, becomes inflamed, and eventually ruptures beneath the surface, spilling its contents into the surrounding tissue. That ruptured spot is what specialists call a “pit,” and it’s the starting point for everything that follows.
Once the skin’s barrier breaks, bacteria that thrive in low-oxygen environments invade the fatty tissue beneath. They multiply quickly, forming an abscess filled with foul-smelling pus. This is the infected pilonidal cyst that sends most people searching for answers. Pilonidal disease belongs to a family of skin conditions that all begin the same way: blocked hair follicles that rupture and trigger infection.
Who Gets Pilonidal Cysts
The condition overwhelmingly strikes younger people. It peaks in the late teens to early twenties, tapers off after 25, and rarely appears after 45. Men develop it three to four times more often than women, though in children the ratio flips, affecting girls four times as often as boys. White patients are affected more frequently than other groups.
Several factors raise your risk:
- Thick, coarse body hair. Stiff hair is more likely to get trapped in stretched follicles.
- Prolonged sitting. Desk jobs, long commutes, and extended driving create constant pressure and friction over the tailbone area.
- Being overweight. Extra weight increases pressure on the buttock crease and creates a deeper, more moisture-prone cleft.
- An inactive lifestyle. Less movement means more sustained pressure on the same spot.
What It Feels and Looks Like
A pilonidal cyst that isn’t infected may cause no symptoms at all. You might notice a small dimple or pit at the top of your buttock crease and nothing more. The trouble starts when infection sets in. The area over the tailbone becomes red, swollen, and tender. Pain can range from a dull ache to sharp throbbing that makes sitting unbearable. Many people notice warmth radiating from the spot.
As the abscess grows, it may begin draining pus on its own. The discharge is often thick, yellowish, and foul-smelling, sometimes streaked with blood. You may also develop a low-grade fever. Some people experience repeated cycles: the cyst flares, partially drains, settles down for weeks or months, then returns. This chronic pattern is common and is a sign that the underlying sinus tract has not healed.
Treatment for an Acute Flare
The most common first-line treatment for an infected pilonidal cyst is incision and drainage. It’s a straightforward procedure done in a doctor’s office under local anesthesia. The doctor numbs the skin, makes a cut into the cyst, and drains the fluid and pus. The wound is then packed with gauze and left open to heal from the inside out. You’ll need to change the gauze regularly, and full healing takes up to four weeks.
This procedure relieves the immediate pain and clears the infection, but it doesn’t remove the sinus tract or the pits where debris collects. That’s why many people who undergo simple drainage eventually have the cyst come back.
Surgical Options for Recurring Disease
When pilonidal disease keeps returning, surgery to remove the sinus tract and reshape the area becomes the next step. Several techniques exist, and they differ mainly in how the wound is closed and how much tissue is rearranged.
Wide excision removes the entire affected area and leaves the wound open to heal on its own. Recovery is slow, sometimes taking months, but the approach is simple and doesn’t require a plastic-surgery-style closure. Flap procedures take a different approach. The cleft lift, originally developed by surgeon John Bascom, involves moving a flap of skin to flatten the buttock crease and shift the wound away from the midline. By eliminating the deep cleft where debris accumulates, these procedures address the root cause of recurrence. The trade-off is a more involved operation with a longer time in the operating room, but healing is generally faster than with an open wound.
Recurrence rates depend heavily on the patient’s age and the technique used. In older adults, the five-year recurrence rate after surgery sits around 11.5%. Young adults fare slightly better at roughly 8.7%. Children and adolescents, however, have a much higher recurrence rate of about 45% over five years, likely because the hormonal changes of puberty keep driving hair growth and follicle activity in the area.
Preventing Recurrence
Both the American Society of Colon and Rectal Surgeons and the American Pediatric Surgical Association recommend conservative strategies as a baseline: daily hygiene of the buttock crease and regular hair removal from the area. Keeping the cleft clean and free of loose hair reduces the raw material that feeds new cysts.
Laser hair removal has emerged as one of the more promising preventive tools. A pilot study of patients with moderate to severe pilonidal disease found that after a median of six laser sessions, all 15 patients who completed treatment showed significant reduction in hair follicle density, with no adverse events. Notably, 40% of those patients saw their disease resolve without ever needing surgery. Quality of life scores improved substantially across the group. Other research has shown that laser treatment after surgery extends disease-free remission compared to surgery alone and lowers overall healthcare costs.
Beyond professional treatments, practical daily habits matter. Avoid sitting in one position for hours without breaks. If your job requires prolonged sitting, stand and move every 30 to 60 minutes. Keep the area dry, since moisture encourages bacterial growth. Losing excess weight, if applicable, reduces pressure on the cleft and makes the area easier to keep clean. Some people find that shaving or using depilatory creams between laser sessions helps keep hair from accumulating, though razor irritation can sometimes make things worse, so finding the right method takes some trial and error.