These are three very important factors in regards to life insurance.
Greater age will equal greater cost of life insurance. The reason for this is simple: the more aged you are, the more likely it is that you will die. This is the second most important factor.
Gender affects life insurance in a similar way. Females, on average, live a longer life than males do. This is why being male means that life insurance will cost more. While it plays a role, gender is the least important factor that goes into consideration.
Good health will lower insurance costs while poor health will increase the rates. By having poor health, a person has a smaller number of years to pay premiums, which will be much higher for a person with poor health. This cuts into the time the insurance company has before possibly having pay for a claim. It is even possible that a person in bad health might not be insurable. This is the most important factor.