Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain a tender lump just beneath the tailbone can be most probably due to formation of a Pilonidal
cyst and is mostly containing hais and skin debris in it..
It is commonly formed due to infection in hairfollicles, infected glands on skin while at times rubbing of skin, wearing tight clothes and long hours of sitting can be a cause..
I would suggest you to
consult a Proctologist and get evaluated and a thorough clinical evaluation is generally enough for diagnosis.
In case if Pilonidal cyst is confirmed as the diagnosis, you be advised to go for enucleation of the cyst followed by a course of antibiotics and anti inflammatory painkillers..
You can also be advised to wear loose fitting clothes as well as avoid sitting for long hours.
Keep the area clean to prevent secondary infection.
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.