Pilonidal Cyst: Symptoms, Causes, and Treatment
Updated: 1 hour ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
TL;DR: A pilonidal (pie-low-NIE-dul) cyst is a pocket in the skin that usually contains hair and skin debris, and it almost always forms near the tailbone at the top of the buttocks. Most cases develop when loose hairs puncture the skin and become embedded, with sitting, friction, and tight clothing pushing the hair in. Infected cysts cause pain, swelling, and pus or blood leaking from a small pit in the skin. A pilonidal cyst is not dangerous by itself, but it is often treated with a small in-office drainage procedure, and recurring cysts may need surgery.
Quick Answer
What is a pilonidal cyst? It is an unusual pocket in the skin, usually filled with hair and skin debris, that almost always forms near the tailbone at the top of the buttocks.
What does it feel like? An uninfected cyst may cause no symptoms, but an infected one is painful, with swollen, inflamed skin and sometimes pus or blood draining from a small pit.
What causes it? Loose hairs puncture the skin and become embedded. Friction and pressure from sitting, rubbing, cycling, or tight clothing push the hair in, and the body forms a cyst around it.
Who gets it most? Pilonidal cysts are most common in young adult males, and the problem tends to come back.
How is it diagnosed? A health care provider diagnoses it by asking about symptoms, habits, and medical history, and by examining the skin.
How is it treated? Most are treated in the office with a small cut that drains the cyst. If it keeps returning, surgery removes the cyst.
How serious is it? Infected cysts are painful but treatable. Left untreated and repeatedly infected over years, they slightly raise the risk of a skin cancer called squamous cell carcinoma.
What Is a Pilonidal Cyst?
A pilonidal cyst (pronounced pie-low-NIE-dul) is an unusual pocket in the skin that usually contains hair and skin debris. The cyst almost always forms near the tailbone, at the top of the crease between the buttocks.
Many people never notice a pilonidal cyst. Some cysts cause no symptoms at all. But if a pilonidal cyst becomes infected, it can be very painful.
Pilonidal Cyst Symptoms
A pilonidal cyst may not cause any symptoms. When it does, the warning signs usually come from infection, which makes the skin around the cyst swollen and painful.
Symptoms of an infected pilonidal cyst include:
Symptom | What to look for |
A pit in the skin | A small hole near the top of the buttocks crease |
Pain | Often near the tailbone, especially when sitting |
Inflamed skin | Skin around the cyst is red and irritated |
Swollen skin | The area looks and feels puffy |
Draining pus or blood | Fluid leaking from an opening in the skin |
Odor | A smell coming from the draining pus |
When to See a Doctor
If you notice any symptoms of a pilonidal cyst — a painful lump, a draining pit, or inflamed skin near the tailbone — see your health care provider.
Seek care promptly rather than waiting, because a draining cyst is an infected cyst, and infected cysts rarely settle down on their own.
What Causes a Pilonidal Cyst?
The cause of most pilonidal cysts is loose hairs that puncture the skin. Friction and pressure from rubbed skin, tight clothing, cycling, or long periods of sitting can force the hair into the skin.
The body then creates a cyst around the hair to try to push it out. That trapped pocket of hair and skin debris is the pilonidal cyst.
Most pilonidal cysts form on the tailbone. In a less common twist, people who groom animals or cut hair can develop a cyst between their fingers, from loose hairs driven into that skin.
Risk Factors
Several factors may increase your risk of a pilonidal cyst.
Risk factor | Why it matters |
Being a young adult male | Pilonidal cysts are most common in this group |
Being overweight | Adds pressure and friction near the tailbone |
Inactive lifestyle | Less movement means more constant pressure on the skin |
Sitting for long periods | Constant sitting pressure forces hairs into the skin |
Thick, stiff body hair | Stiffer hairs puncture the skin more easily |
Complications
The main problem with pilonidal cysts is that they tend to recur. Some people have cysts that become infected again and again over a long time.
Without treatment, people with long-term, repeatedly infected pilonidal cysts may be at increased risk of a type of skin cancer called squamous cell carcinoma. This is one reason chronic, draining pilonidal disease should not be ignored.
How Is a Pilonidal Cyst Diagnosed?
Diagnosis is usually simple. Your health care provider can often diagnose a pilonidal cyst by asking about your symptoms, medical history, and personal habits, and by looking at the affected skin.
No scans or lab tests are typically needed. The exam of the skin near the tailbone, combined with your history of pain and draining, is usually enough.
Pilonidal Cyst Treatment
A pilonidal cyst is usually treated in your health care provider's office. After numbing the area, the provider makes a small cut to drain the cyst. This simple procedure relieves the pressure and pain.
If the cyst returns, you may need surgery.
Surgery Options
If you need surgery, your health care provider numbs the area and removes the cyst through an incision. After removing the cyst, there are two ways the wound can be handled:
Healing option | How it works | Trade-off |
Leave the wound open | The surgeon leaves the wound open and packs it with dressing, allowing the area to heal from the inside out | Takes longer to heal, but makes it less likely the cyst will come back |
Close the wound with stitches | The surgeon closes the wound with stitches | Shorter healing time, but a greater risk of the cyst coming back |
Wound Care After Surgery
Wound care is very important after surgery. Your health care provider will show you how to change dressings and explain what to expect during the healing process. You will also be told when to call your health care provider.
You may need to shave around the surgical site to prevent hairs from entering the wound.
How to Prevent a Pilonidal Cyst
To help prevent pilonidal cysts, try to follow these habits:
Prevention step | What it does |
Wash regularly | Keeps the skin near the tailbone clean |
Achieve or maintain a healthy weight | Reduces pressure and friction in the area |
Avoid prolonged sitting | Less sitting pressure means fewer hairs forced into the skin |
Shave the area or use hair removal products (if you have had cysts before) | Reduces the chance of loose hairs entering the skin and forming a new cyst |
Preparing for Your Appointment
You are likely to start by seeing your primary care provider. In some cases, when you call to set up an appointment, you may be referred immediately to a surgeon or to a dermatologist — a doctor who specializes in treating skin conditions.
What You Can Do
Before your appointment, you may want to write a list that answers the following questions:
Your question | Why it helps |
When did your symptoms begin? | Shows how long the problem has developed |
Have you experienced this problem before? | Recurrence changes the treatment plan |
Does anything improve your symptoms? | Points to useful habits to continue |
What, if anything, appears to worsen your symptoms? | Reveals friction, sitting, or clothing triggers |
What medications or supplements do you take regularly? | Affects numbing, surgery, and healing |
What to Expect From Your Doctor
Your health care provider is likely to ask you a number of questions, including:
Provider's question | What it tells them |
Have you had a fever? | Checks whether the infection is spreading |
Is the pain keeping you awake at night? | Gauges how severe the infection is |
What is your occupation? Do you sit all day? | Identifies a likely pressure and friction trigger |
Conclusion
A pilonidal cyst is a small but genuinely painful problem that starts with something simple: a loose hair pushed into the skin near the tailbone. The good news is that most cases are handled with a quick in-office drainage, and surgery is reserved for cysts that keep coming back. Keeping the area clean, staying active, and avoiding long stretches of sitting can help prevent the problem — and if it returns, acting early keeps treatment simple.
If you notice a painful lump, a draining pit, or swollen skin near your tailbone, see a health care provider. It is an easy problem to treat early — and a hard one to ignore.
Frequently Asked Questions
What is a pilonidal cyst?
A pilonidal cyst is an unusual pocket in the skin that usually contains hair and skin debris. It almost always forms near the tailbone at the top of the buttocks. The name describes its location: "pilonidal" means "nest of hair" in Latin.
What does a pilonidal cyst feel like?
An uninfected cyst may cause no symptoms. An infected one is painful, with swollen, inflamed skin near the tailbone. You may notice a small pit in the buttocks crease, and pus or blood may leak from an opening in the skin, sometimes with an odor.
What causes a pilonidal cyst?
Most pilonidal cysts are caused by loose hairs that puncture the skin. Friction and pressure from rubbing, tight clothing, cycling, or long periods of sitting push the hair into the skin, and the body forms a cyst around it to try to push the hair out.
Is a pilonidal cyst dangerous?
An infected pilonidal cyst is painful but treatable, and it is not dangerous on its own. However, cysts that become infected repeatedly over a long time, left untreated, can raise the risk of a skin cancer called squamous cell carcinoma.
How is a pilonidal cyst treated?
Most pilonidal cysts are treated in the doctor's office. After numbing the area, the provider makes a small cut to drain the cyst. If the cyst keeps returning, surgery removes it through an incision, and the wound is either left open to heal from the inside out or closed with stitches.
Does pilonidal cyst surgery hurt?
The procedure is done after numbing the area, so you should not feel pain during it. Wound care afterward is important: you will be shown how to change dressings, and you may need to shave near the surgical site so hairs do not enter the wound.
Will a pilonidal cyst come back?
Pilonidal cysts tend to recur, which is why the problem can repeat. Leaving the surgical wound open heals more slowly but is less likely to come back. Stitching it closed heals faster but carries a greater risk of return.
How can I prevent a pilonidal cyst?
Wash regularly, achieve or maintain a healthy weight, and avoid sitting for long periods. If you have had pilonidal cysts before, regularly shaving the affected area or using hair removal products can reduce the risk of a new cyst.
Should I see a doctor or a dermatologist for a pilonidal cyst?
You are likely to start with your primary care provider, who can often diagnose and drain the cyst in the office. In some cases, you may be referred immediately to a surgeon or a dermatologist (skin specialist).
External References
Roberts JR, et al., eds. Incision and drainage. In: Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Elsevier; 2019.
Pilonidal disease — American Society of Colon and Rectal Surgeons
Ferri FF. Pilonidal disease. In: Ferri's Clinical Advisor 2023. Elsevier; 2023.
Cutaneous cysts. In: McKee's Pathology of the Skin. Elsevier; 2020.
References
Disclaimer: This article is for general educational purposes only and is not a substitute for professional medical advice. Always consult a qualified health care provider for diagnosis and treatment.
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