Bad cramps

I'm 17, over 6 feet tall, 155 pounds. Whenever I run or jog for too long, which can be less than 100 meters for me I get these really bad cramps right underneath my ribcage, almost as if a snake is biting me from the inside, and even if I try to walk it off it just gets worse. If I stop walking for a couple minutes they go away. I'm not sure if this is a serious  health risk but I've been like this since I was a child, and I was rather active as a child as well. Even in grade 5 once I got the same cramps and my teacher told me to walk it off but it got so bad that it made me cry. And in grade 2 I was playing kickball for gym and I ran 2 bases the most maybe and that gave me the same painful cramps.