Is it normal for a fish to lay on the bottom of the tank and swim up to the top then back down?

if its a betta fish they will do that sometimes. if it is tired it will sleep at the bottom (just to make sure its sleeping and not dead, tap the glass gently to see if it moves a bit) but it will go back up to breathe since they do breathe air if its another fish maybe its sick or it might want to make some bubbles with its mouth.