A pilonidal sinus is a small tunnel or cavity that forms in the skin, often near the top of the cleft of the buttocks. This condition is thought to be caused by hair penetrating the skin, which can lead to infection and the formation of an abscess or sinus tract. Common symptoms include pain, swelling, redness, and sometimes discharge of pus or blood from the affected area.

Causes and Risk Factors

• Ingrown hairs: Loose hairs can become embedded in the skin, triggering inflammation and infection.
• Prolonged sitting: This can increase pressure on the area and contribute to the formation of a sinus.
• Male gender and young age: Pilonidal sinuses are more common in men, especially those between the ages of 15 and 30.
• Obesity and thick body hair: These factors increase the likelihood of hair becoming trapped under the skin.