Knowing when to replace your mattress can be a bit of a gamble. You can either wait too long, and end up with a spring in your back, or else replace it when it's got many good years left in it.
There's no real science to knowing when exactly to get a new mattress - however, there are a few foolhardy pointers which will tell for for certain, when it's time to give your mattress the old heave-ho....
Take a look at your mattress. Are there any dips, sags, or imprints that stay there after you get up? This is a common sign of filling wear, and means that years of sleeping in the same position has compressed the fillings. Try turning your mattress over - this can expose a new, less worn sleeping area to sleep on.
Poor Night's Sleep
If you find yourself tossing and turning, and hard to get comfortable, this can be because your mattress does not provide the correct support anymore. If your bed cannot support your back and body properly, this can build up to uncomfortable sleeping posture, leading to a bad nights sleep. Time for a new mattress!
Aching in the Morning
If you wake up to sore muscles, still joints, or aches and pains that disappear after the morning, then this is probably a sign that your mattress needs replacing. These aches are thanks to the muscles being unable to relax, fully supported; therefore building up tension throughout the night.
Over 8 Years Old
Remember when you brought your mattress? If it was in a time when shell suits and poodle perms were cool then DUMP IT! Even if it still is in one piece, a mattress over 8 years old will be in no fit state for you to sleep on, night after night. Remember that in it's lifetime a mattress will double its weight with dust, detritus, and dirt build up. If that doesn't convince you to chuck the old one, nothing will!