This may seem like a stupid question but is there a limit to the amount of cards you can have in your hand? I have it in my mind that its eight and if that is correct does this mean that you cannot draw cards above this limit?

There is no hand limit in Call of Cthulhu. You can have as many cards in hand as you like!

8 cards is how many you draw at the beginning of the game. That is the last time that the number 8 is mentioned in relation to hand size or draw.

Actually, there's a Support card called 'The Book of Eibon' in the Yog faction , which can be attached to an opponent's character imposing a hand limit of 5 cards on your opponent while in play.

Jhaleen is correct, I meant to say the last time it is addressed in the rules.