First off, thank you Phoenix and everyone for all the helpful information on this site!
I’m in my mid-20s. I currently sleep on a 20-year-old firm spring twin mattress, and for the past two years or so, I’ve had a ~1.5 inch foam topper. Lately, I’ve been noticing that I never feel well rested. I downloaded a sleep tracking app. I don’t know how accurate it is, but it says I toss and turn in my sleep a LOT. I also occasionally wake up with light lower back pain.
I tried experimenting with removing the foam topper. The firm spring mattress felt more comfortable for the first few minutes lying on my back, but it quickly became uncomfortable. I often sleep on my side, and it was too hard on my shoulders. I would wake up with even more back pain. I’ve since put the foam topper back on, and it’s better, but still have the issue of light back pain and never feel rested.
I’ve tried sleeping with a pillow under/in between my legs, but I toss and turn a lot so it always ends up somewhere else.
I’m hoping to purchase a nice, larger mattress a few years down the road when I move into a new place and have more money saved up, but until then, I’m looking for a cheaper solution. What would be your advice? Should I shop for a cheap mattress? Do you think a new mattress topper would help? Maybe I should consider other non-mattress factors?
I’m not sure what type of topper you are using but if it’s a lower quality/density material then it’s quite possible that after 2 years it’s past the end of its useful life and has softened or compressed under the heavier areas of your body and in combination with your mattress may no longer suitable for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences).
If your mattress is still in good condition and there are no soft spots or sagging (in either the mattress or the foundation underneath it) and all you need is some additional pressure relief (which is one of the most likely causes of tossing and turning) then another replacement topper may be a good lower budget option that would work well for you. If your mattress is a good candidate for a topper then the topper guidelines in post #2 here and the other posts it links to should be helpful.
If your mattress has soft spots or is sagging then there are no great options but there are some ideas in post #4 here that may be helpful.
If your mattress isn’t a good candidate for a topper then it may be worthwhile looking for a new mattress in a suitable budget range in which case the tutorial post here would be the best place to start and has all the basic information, steps, and guidelines that can help you make the most suitable choice in any budget range.