What Causes Bumps On Shin With Swelling ?

Hi, I train jujitsu and mixed martial arts. I have over the years developed bumps on my shins which I know is quite common. On Thursday however, I developed a lot of swelling both on the right shine bone and on the outside muscle group. The swelling is sore and feels quite warm to touch. I have kept my leg elevated and been treating it with ice which seems to be helping a bit. What do you suggest this could be and what should I do further? Thanks