Although many life insurance companies do not insure people with serious health problems due to the high risk of someone being insured and then not having a long-life expectancy, there are plans called "Guaranteed Issue" life insurance that offer guaranteed approval for anyone who meets the age requirements.
For example, some insurers offer guaranteed coverage to people ages 45-75, 40-80, or even ages 45-85.
If you meet the age requirements, and you can pay the premiums, you are guaranteed approval for a policy.
However, these guaranteed issue plans usually have graded death benefits the first 2 (or 3) years you are insured.
That means, you won't have 100% death benefit coverage until you have been insured for a period fo two years. That's how they can guarantee your approval for a policy.
Learn more about life insurance for people in poor health.