shin splints are very serious, i myself have had surgery on both legs down the inner and outer sides of my shins. the cause can be different for each person, shin splints is merely a term used to discribe problems between just under the knee and just above the ankle.

the best thing to do is stop running and seek a doctors advice, it could be that you have slightly flat feet in which case some orhapidic insole can help, or your dorseflex musles need strenghing, you won't know until you get them checked out