Check with the manufacturer at the time of your purchase as the expected life span of your pillow will really depend on what material is used and the quality of it.

Some pillow manufacturers even provide a tag on the pillow so you can jot down the date you bought it, to see how it's ageing.

The pillow test

For synthetic and feather down pillows you can also try the shoe test to see if your pillow might need replacing:

Put your pillow on a reasonably flat surface and fold it in half.

Put a sports shoe on top.

If the shoe flies off as your pillow bounces back into its original shape, your pillow is in top form.

If the shoe stays there or the pillow doesn't spring back into shape, it's probably time to buy a new one.

It pays to consider a few issues before you go out to buy yourself a new pillow:

How do you sleep and what position do you prefer? Do you like to curl up on your side, sleep on your stomach or crash out on your back?

Are you a tosser and turner or do you sleep like the dead?

Consider your size: do you have a large frame? Are you small or somewhere in the middle?

If you're sharing your bed with a partner don't forget to take their sleep position preferences and body shape into consideration too. Different pillow styles suit different people, so it's smart to make sure you both shop for your own pillows to get one for your individual needs.

Soft or firm?

If you sleep on your stomach or have a small build, a low, soft pillow is best. This is also suitable for children.

If you sleep on your back a medium to firm pillow with a medium profile is the best.

If you sleep on your side mostly or have a bigger body frame, a firm to extra-firm pillow might suit you better.