Your bed is certainly not built to last your entire life time, so don't be afraid to upgrade when your mattress has reached the end of its life. A good rule of thumb is to replace your mattress every 8-10 years, but if you begin to notice lumps, sagging, or indentations, your bed could be ready for an up grade sooner then you think. While mattress can be a big-ticket purchase, don't wait while your sleep suffers. Upgrade to newer bed and give yourself a better night's sleep. A good night sleep is very important for your well being.