I've noticed that mattresses (and pillows) in hotels tend to be softer than I'm used to, and I don't get a good night's sleep like I do at home. I don't have anything super-special going on (no weird medical stuff); I just have a firmer mattress and pillow at home and I notice the difference at hotels, sometimes waking up with a bit of a backache. Is there anything I can do in a hotel room, or when making a reservation, to firm up the bed, within the constraint that when I fly I try not to check baggage? (So if I bring something, it has to pack down.) I don't want to sleep on the floor (that's too firm).
I found a helpful video for exactly this problem - and it's an easy solution: just put a pillow under your midsection and your spine will be much better supported. http://youtu.be/DQgpE3DIcXs
One thing I noticed is that more expensive hotels tend to have softer mattresses and fluffier pillows.
While probably not universal, it might be worth experimenting with selecting a slightly lower class hotel, or just a different chain.
In extreme cases, sleeping on the floor is of course an option, even at home I have to do that sometimes when I've a severe attack of back pain (and my mattress there is pretty hard indeed).
But if your back is healthy, the aches waking up in a strange bed have more to do with the bed being strange and not shaped/moulded to your body as the one you have at home is than with the specific firmness of the mattress and bottom (the stiffness, shape, and movement of the springs or wooden slats the mattress is sat on have a big influence as well on your nightly comfort).
You will notice the same thing the first several days to weeks after purchasing a new mattress for your home.
Some hotels offer a choice of mattresses, not advertised but it is worth asking.
I had an uncomfortable night at one large hotel because the mattress was too hard for me. I called the front desk to complain. The next night there was a much softer mattress on the bed.
Check for online reviews about the bedding. When I see "too hard" I think, "perfect for me." Also, you can call the front desk of hotels before you reserve a room and ask what guests typically say about the beds.