Applying for life insurance does not guarantee an insurance company will sell you a policy. Your application goes through an underwriting process during which your eligibility for insurance is evaluated, which includes a review of your medical history and a physical exam. Personal health problems can lead to higher premiums or even a complete denial of coverage. Examples of health conditions that may affect your insurance costs and eligibility include cancer, heart disease, diabetes, high blood pressure and being overweight. If you develop serious health issues after getting life insurance coverage, your policy will not be affected. To improve your chances of qualifying for coverage and making your premiums more affordable, it’s advantageous to buy insurance while you’re young and healthy.