That happends to me some times too. Here are the usual reasons
-something trajic happened that day
-you got no sleep the nite before
-you had a lot of sugar before
-just went though a bad brake up
-you saw or herd something that could of scared you, but you don't think
it scared you
but if its not one of those, I honestly don't no because my father is a reasearcher
and wen that happened to me. He looked it up and told me those were the
usual reasons
-something trajic happened that day
-you got no sleep the nite before
-you had a lot of sugar before
-just went though a bad brake up
-you saw or herd something that could of scared you, but you don't think
it scared you
but if its not one of those, I honestly don't no because my father is a reasearcher
and wen that happened to me. He looked it up and told me those were the
usual reasons