Based on that information medical records may be ordered from the applicant's doctors.
Also, life insurance carriers access the MIB or Medical Information Bureau to review all medical information provided to insurers previously and whether or not someone had been declined for life insurance by a previous carrier.
Checking prior medicals is simply part of due diligence to avoid fraud on the part of the applicant.
Most life insurance policies require a paramedic exam which is paid for by the insurance company. In addition, a medical history will usually include health questions on immediate family members.
The insurer may consider the applicant's health and lifestyle including tobacco use, STD's, legal and illegal drug use, height-to-weight ratio, and family health history, among other things.
Learn more about a life insurance medical exam.