Insurance companies price policies based on mortality tables that capture data on death rates for various customer segments. Higher the risk of death higher the premium. Some of the factors that can influence your price include:
Your age: older people pay more
Your gender: women pay less than men
Your tobacco consumption habits: pay more if you consume tobacco
Add-on benefits: pay more if you include optional benefits like critical illness cover, etc.
Medical history: pay more if you have certain medical conditions/complications
However, once bought, the premium stays constant throughout, as long as the policy is renewed without a break. Prices differ across insurers – so make sure you compare before you buy.