About a month ago I noticed a bump on the back of me heel.. about the size of a dime. At the time i pressed it and examined it.. thinking perhaps it was a blister. it does not hurt.. but i've noticed that it has grown in size slightly.. and this evening while pressing on it.. i noticed a sound and feeling as if well the sound was as if cracking your fingers.. and the feeling like i had popped an air bubble inside of my foot... it scared me so i massaged it to see if i could make it happen again. After about 5 minutes I gave up and got up from my chair to get something to drink.. the moment i put pressure on the foot.. the same sound.. happened and in the area of the bump.. there was that feeling of the air. I've never heard of this before.. and trying to find information about it on the net has been hard.. i was wondering if anyone else has had this problem.. or could point me in some directions. I'm not extremly worried about it.. as it does not hurt. I have looked up a few things such as Haglund's Deformity. but it is not hard. I should also mention that i had a problem with my heel cracking for a few months.. and with extensive soaking and vasaline.. i've managed to get it to heal some.. could this be the cause of it. any information or suggestions please?

Its possible its a "pump bump", search it out and see if it sounds like your problem.