I have had a bump on the top of my head for 20+ years, over the past 10 years it has been growing it is now maybe a 1/2" wide and 3/8" tall, and over the past 3 years another one has been growing rapidly on the side of my head and is now about the size of the other one.  They are hard.  Well about a week ago the one on the side had started to become very painful and soft, when I pull my fingers through my hair I scratch it with my nails and I noticed a scab one morning and removed the scab and liquid came out, then I squeezed it and a lot of pus came out.  I have squeezed it again last night in the shower and it is still squeezing out pus.  Should I be alarmed?
Hi, From history it seems that you might be having infected sebaceous cyst giving rise this problem. Up till now there was no infection, so they remained silent. As there is infection, they started increasing and got burst open. Consult surgeon and get examined. These cysts are to be excised with sac to get complete cure. Ok and take care.