Yep, what everyone has posted so far is correct. You have to declare if you have any known conditions, you also have to declare if any of your close relatives died from or suffer from certain conditions, and the companies often seek a report from your GP before they decide a) if they can take you on and b) what premium they will charge you. There are hundreds of life assurance companies and a great many different types of policies - whole of life, term assurance, etc - it's worth shopping around and taking impartial advice if necessary.