Hello, I had a question about sudden bruising on my legs, more specifically on my calves. They have been popping up for years, from my ankles to my knees, and I want to know what is the cause? Just yesterday, I had a huge protruding bump appear on the leg and is now forming into a big bruise. I ve had this for years but it s never protruded out before and now I m worried. I ve tried doing research and all the results of diabetes, leukemia, kidney and liver problems are not helping. I m young, in my early 20s, and live an active, healthy, vegan lifestyle. This leads me to believe the problem is something beyond lifestyle choices, such as not being active or being overweight.