I think you're better off buying a cheap foam mattress, in most cases, than buying a cheap spring or air mattress.
The reason I say that is because cheaper spring mattresses can be so poor as to not give you any back support, especially in the lumbar area where you so desperately need it.
You can check the back support characteristics of any mattress right while you're lying on it in a store. It only takes a couple seconds to know if it will be a back breaker once you've got it home.
While you're in the store, lie down on your back and then try sliding your hand between the mattress and the small of your back.
Now don’t raise up or turn your body in any way to make it easier; just lie flat on your back when you're doing this little mattress experiment.
With a poor mattress, you will easily be able to slide your hand in between the small of your back and the mattress.
In fact, most doctors will tell you to sleep on a very firm mattress which, in my opinion, is one of the worst things you can do to your lower back.
Just to illustrate this, try lying on the floor on your back.
The floor is the firmest surface you could sleep on and your low back will be curved up above the floor so it's not getting one ounce of support.
That's the real story of a firm mattress being the best thing for your back—it's not. (I’m not a doctor, but it makes common sense, doesn’t it?)
If it's difficult to slide your hand between the small of your back and the mattress, it's because the mattress is pushing up against your back and giving support.
Now, the next thing you want to think about is memory foam and the nature of it. Because it tends to allow your body to sink in further at the shoulders and hips, it more naturally supports the low back lumbar area.
Does that make sense to you? I hope so because it's the real answer to waking up each morning refreshed with no back pain.
I suggest that the density of memory foam is the key to getting the proper support your body needs.
On this website, I've always recommended 5 lb. density or more.
The reason is that it's more supportive than lower-density memory foam and lasts longer than less dense, cheap foam mattresses.
Having said that, it's not that you shouldn't consider foams down to 4.0 lb. density—just that they won't have a 20-year warranty and won't give you the same level of support that you'd get from 5 lb. foam.
Another alternative to the more expensive mattresses is the large-cell memory foam rated at 5 lb. density.
These foams aren’t as heavy and some people say they sleep cooler than the true 5 lb. density memory foam but in any case, they are normally priced less than the others so it makes them an attractive alternative if you can’t afford the true 5 lb. density foam mattress.
They'll still outperform most spring mattresses of any price.
Because these foams haven’t been around as long as the older, denser foams, they aren’t really proven yet and so don’t have the longer track record that the true density foams have.
Still, they provide a great amount of support. They deaden motion transfer from a restless sleep partner and they can give you a great night’s sleep compared to spring or air mattresses.
The obvious problem with air mattresses, besides not giving you the support you need, is that anything that’s aired up will also leak and at some point will not hold air for more than a couple of hours per night.
