Typically you'll find renewal periods of from 10 to 20 years. So even if you're hanging on to life by the thinnest of threads at renewal time, you'll be able to keep your insurance. Many younger people favor term insurance during their 20s and 3's. After all, it is cheaper. With this type of insurance, as long as you continue to pay the premiums, you'll have coverage.
Permanent insurance goes by a variety of names.
Basically, they're all variations on the same policy. Here you'll pay a consistent premium for the rest of your life. The premium is split into two parts. One part actually pays for the life insurance for that year. The other part is invested in the early years and can be used to pay your premium in later years.