The Pilonidal Sinus is a type of a cyst or a hole found in between or at the top of the butts which may sometimes one or many and they all are connected with the tunnels under the skin and are generally found in people above the age of 35. The Pilonidal Sinus contains hairs, dust and these two are also the main cause of this disease. Sometimes this type of disease is by birth, small hairs near the butts later it results in where hairs  stick in the skin and sometimes it becomes irritating and as a result of inflammation of the skin between the butts. The inflamed skin later gets in contact with the cloths and get infected very easily which result in the cause of sinus which contain the pieces of hairs. These types of cyst are not easily noticeable, but one can identify the redness or pain in the area where this type of cyst is present, this may not be the always cause of this disease but in some cases this may be. The cyst is formed around hair follicles (the tiny holes in the skin where the hairs are grown). The cause of such disease is still not found, but majorly it is due to pressure or friction to the skin.

CAUSES AND SYMPTOMS 

• Obesity.
• A previous injury to the skin.
• Family history.
• Regular irritation in particular, part of the body.
• Spending more time sitting.
• Pain and swelling in the buttocks.
• Dust particles.
• Redness.
• Difficulty in urinating.
• Feeling sick.
• Fever.
• Heavy growth of body hairs.
• Back pain.
• Pressure or friction to the skin.
• Acute Infection- if you have a serious symptom that developed too quickly, then you may have to operate the same for draining the sinus of pus. 
• Chronic Infection- this is when the infection keeps on coming back. The best treatment for this is also an operation

TREATEMENTS:-Regular cleaning and dressing the area which is operated or if not operated applying the prescribed medication or tube on it. Not using soap on the inflamed area, keeping the area dry, no using of creams unless it is being prescribed,eating as much of fibers like fruits, vegetables etc.