The life insurance company tests you to look for any diseases, and any use of illegal substances. They may also be able to determine what drugs and prescriptions you are on, and if you use tobacco or have nicotine in your system.
You may want to consider
term life insurance no exam required. However, always make sure you answer all questions truthfully on your life insurance application, because they can contest your coverage if you die and they find out you did not tell the truth on your application.