You spend about a third of every day in bed. Whether that time is spent blissfully slumbering or tossing and turning depends a lot on your mattress.

One way that your mattress affects your sleep has to do with the network of fine blood vessels, called capillaries, that run beneath your skin. When you lie on any part of your body for an extended period of time, the weight reduces blood flow, depriving the skin of oxygen and nutrients.

This causes nerve cells and pain sensors in your skin to signal your brain to roll over. Rolling restores blood flow but also briefly interrupts your sleep.

Where memory foam mattresses help is when you have an active bed partner. Foam mattresses reduce motion transfer, letting you lie still while your partner tosses and turns.

You wouldn’t buy a car without test-driving it. So why invest hundreds or thousands of pounds in a mattress without trying it? Take any new mattress for a test nap. People shouldn’t be embarrassed to lay on a mattress for 20 minutes.

For a more realistic test, sleep in hotel beds when travelling. If you get an especially good night’s sleep, ask the hotel what brand it is or pull the mattress to find the label.

When you test a mattress, make sure it feels comfortable in every position, especially the side you favour. It should be supportive without creating pressure points.

If you’ve been having trouble sleeping, the problem might be your mattress age. Mattresses have a lifespan. Keep yours too long and internal materials break down, reducing support.

The general guideline is to change your mattress every 10 years. If you feel pain or generally un-rested after sleep, it’s time to shop again.

One more thing to consider is learning how to sleep well. You may have a sleeping disorder affecting your rest. Before heading to a bed store, try the holistic approach.