Fitness Goals Support Group
This community is dedicated to group support around achieving fitness goals, whatever they may be, through personal training, athletic activites, or other strenuous activity. Whether you are trying to get fit to treat a health problem, boost your mood, relieve stress, or tone your body, this group is a great place to meet other like-minded people who have similar goals.
http://www.medicalnewstoday.com/articles/21555.php
They both mentioned dont assume its from being dehydrated and from running. It says to go see a doctor just to be sure and rule out any other things. Its better to be safe then sorry... Im glad you brought this us cause i would of freaked out. If it does happen to me I will still go to a doc.