I woke up with lower back pain every morning for six months. I blamed my mattress, but a new mattress cost eight hundred dollars and I was not ready for that. A physical therapist friend suggested a mattress topper instead. One hundred dollars later, I wake up without pain.

Here is what I learned about picking the right topper for back pain.

Firmness is not what you think

Most people with back pain assume they need a firm sleeping surface. That is only true for some people. The goal is spinal alignment: your spine should be in roughly the same position it is in when you stand up straight. If your mattress is too soft, your hips sink and your spine curves. If it is too firm, your hips stay elevated and your lower back bridges over empty space.

A topper adjusts your existing mattress toward the right firmness. If your mattress is too firm, you want a softer topper. If your mattress is too soft, you want a firmer topper. Buy the opposite of what you have.

Memory foam: Best for pressure relief

Memory foam conforms to your body shape and distributes your weight evenly. This reduces pressure points on your hips and shoulders. Look for a density of at least 3 pounds per cubic foot — anything less will flatten out within a few months.

The Linenspa 3-inch gel-infused memory foam topper (about $50 for a twin, $80 for a queen) is the one I bought. The gel infusion helps with heat retention — standard memory foam sleeps hot, which wakes some people up at night. The gel version stays cooler.

Latex: Best for support and durability

Natural latex is firmer and more responsive than memory foam. It pushes back instead of sinking in. This is better if your back pain is caused by a mattress that is too soft — the latex adds support without being hard. Latex also lasts longer than memory foam (eight to ten years vs. three to five).

The Pure Green 2-inch natural latex topper costs about $100 for a queen. It is firmer than memory foam and sleeps much cooler. The trade-off is that it is heavier and harder to move around.

Egg crate foam: Skip it

Those textured foam toppers that look like egg cartons are cheap — $20 or less — but they compress after a few weeks and offer almost no support. Save your money for a denser foam. An egg crate topper is slightly better than nothing, and only for about a month.

The trial period matters

Give a new topper at least two weeks before deciding. Your body needs time to adjust. If you have been sleeping on a bad surface for months, your muscles have adapted to compensate. A correctly supportive surface can feel “wrong” at first because your muscles are not used to relaxing.

If the pain gets worse after the first week, the topper is probably not right for you. If it gradually decreases, stick with it.

I have been sleeping on the Linenspa topper for eight months now. The back pain has not returned. For eighty dollars, that is better than any pricey mattress I could have bought.