Feeling Faint When Standing

Does anyone else ever start to feel sick and like you're going to pass out when standing in one place for too long? I've noticed that whenever i'm up doing the dishes or taking a shower that i'll start getting heart palpitations, feeling nauseated, and feeling like i'm gonna pass out. Sometimes i try to ignore it so i can continue what i'm doing, but if i wait too long i'll start seeing black dots and that's when i really go sit or lay down. It only happens when i'm standing in one place, but walking around i'm fine. Should i mention this to my OB?