- Article medically reviewed and fact-checked by Dr. Dimitar Marinov (M.D, Ph.D, RDN) for accuracy.
Mattress firmness describes how hard or soft a mattress feels when you lie on it.
But if you have back pain, should you go for a firm or a soft mattress?
A soft mattress is better for lighter weighted sleepers under 150 lbs, side sleepers, and skinny sleepers with back pain due to pressure reduction; whilst a firm mattress is better for heavier weighted front and back sleepers over 200 lbs due to the increased surface tension that can maintain good posture.
The rest of this article explains the types of mattress firmness, material, and layering design combinations that are potentially the best for alleviating back pain.
Alternatively: if you’re ready to buy a new mattress then check out my list of the best mattresses and adjustable beds to help with back pain in 2021 for some excellent deals.
Are Firm or Soft Mattresses Better For Back Pain?
Both firm and soft mattresses can be good for back pain.
Because whilst a study concluded that a medium-firm mattress resulted in a reduction of back pain in the cervical, dorsal and lumbar regions in older adults with musculoskeletal pain , and the status quo is that a firm mattress (or even sleeping on the floor ) is better for back pain, the truth is that soft and firm mattresses both help or even CAUSE back pain.
This apparent paradox is true due to the difference in body weights, body types, and the preferred sleeping positions between individuals.
For example, whilst a soft mattress may not provide enough support for a heavier weighted front sleeper over 230 lbs and could actually contribute to back pain, a lighter weighted side sleeper under 150 lbs may find that their back pain reduces because the lower surface tension allows the sleeper’s hips and shoulders to sink more deeply into the materials to facilitate better posture.
However, the same 230 lbs+ front sleeper may experience a reduction in back pain whilst sleeping on a firm mattress because the increased surface tension can help to guard against excessive material sinkage and thus maintain an ideal posture to combat back pain – whilst the lighter weighted side sleeper would likely experience pain and discomfort on the same firm mattress due to the pressure points that it creates as a result of not being able to sink far enough into the mattress materials.
Below, I’ve summarized the best sleeping positions, body weights, and body types that map to each type of mattress firmness to help guide you towards the best mattress firmness for your back pain.
Firm – Best For Front and Back Sleepers Over 200 lbs
Firm mattresses tend to be better for heavier weighted front and back sleepers over 200 lbs with back pain because the tighter surface tension and reduced capacity for material compression can help to stop you from sinking too deeply into the mattress materials and instead help to keep your spine and lower back well supported so that your body is being placed under less strain.
Firm mattresses can be divided up into extra-firm, firm, and medium-firm with subtle differences that are as follows:
Extra-Firm – Ideal For Front Sleepers Over 250 lbs
Extra firm mattresses (sometimes referred to as orthopaedic mattresses) are best suited to the heaviest weighted front sleepers over 250 lbs with back pain because the maximal surface tension can help to keep your hips in the proper position and guard against your lower back from painful ‘hammocking’.
However, due to this relatively extreme level of firmness, you should choose an adaptive material like memory foam or latex foam in the upper comfort layer to off-set the pressure points that it may create on your body (more on material selection in the next section).
Firm – Best For 230 – 250 lbs Front and Back Sleepers
A firm mattress is best suited to front and back sleepers with back pain in the 230 – 250 lbs range because the higher than average surface tension can help to push back against your body weight for protection against poor posture whilst you’re lying down.
And whilst the level of firmness isn’t as high as that of an extra-firm mattress, going for a latex foam or memory foam top layer can help to soothe any pressure points that may arise as a consequence of the firmer feel.
Medium-Firm – Suitable For 200 – 230 lbs Front, Back, and Side Sleepers
Medium-firm mattresses are best for front, back, and side sleepers with back pain in the 200 – 230 lbs range because whilst the touch of extra firmness can help to maintain good posture as you sleep on your front or your back, there’s a little more ‘give’ that allows side sleepers to sink more into the materials to achieve optimum posture.
However, if you’re a side sleeper with back pain closer to the 200 lbs end of the spectrum, then you’ll likely want to go for a mattress with adaptive memory foam or latex foam in the top layer to help reduce the pressure on your hips and shoulders.
Soft – Best For Side Sleepers and Sleepers Under 150 lbs
Soft mattresses tend to be better for lighter weighted sleepers under 150 lbs and sleepers with a lower body fat percentage – especially in the side sleeping position – with back pain because the reduced surface tension allows you to sink more deeply into the mattress materials to off-set the pressure that would normally build up on your body and in your joints on a firmer mattress.
Soft mattresses can be differentiated further into extra-soft, soft, and medium-soft firmnesses as follows:
Extra-Soft – Ideal For Side Sleepers Under 130 lbs
Extra-soft mattresses are best suited to the lightest weighted side sleepers under 130 lbs with back pain because the maximal ‘give’ afforded by the surface of the mattress can help to dissipate your body weight more evenly across the mattress to reduce the pressure in your joints.
Mattresses with memory foam in the upper comfort layer can be especially beneficial for lighter weighted side sleepers and/or sleepers with a lower body fat percentage because the foam can adapt to your unique body shape to soothe the pressure that you would typically feel on a firmer mattress surface.
Soft – Best For 130 – 150 lbs Side Sleepers
Soft mattresses are best suited to lighter weighted side sleepers in the 130 – 150 lbs range because the softer than average surface tension allows you to sink into the materials more for better pressure relief.
Medium-Soft – Suitable for 130 – 150 lbs Front, Back, and Side Sleepers
Medium-soft mattresses are best for front, back, and side sleepers in the 130 – 150 lbs range because the touch of extra softness allows for a more even distribution of your body weight across the mattress but not so much that you sink in too far and drop out of good posture.
Medium – Best For 150-200 lbs Front, Back, and Side Sleepers
Mattresses with a medium level of firmness are best for front, back, and side sleepers in the 150 lbs – 200 lbs range because they provide the ideal amount of surface tension to keep you in good posture.
However, many front, back, and side sleepers in the 130 – 150 lbs and 200 – 230 lbs weight ranges may also be comfortable in a medium firmness mattress depending on personal preference.
How Does Mattress Design Affect Back Pain?
Mattress design can affect back pain both positively and negatively depending on how the mattress materials interact with your body type, body weight, and dominant sleeping position.
Below is a breakdown of how the materials, support, and layer design can affect your back pain and your potential comfort levels:
1: Materials – Impacts Pressure Relief and Support
The materials that your mattress is primarily made from can make a huge difference to how comfortable you feel in your mattress if you have back pain:
Memory foam mattresses are best for lighter weighted sleepers, sleepers with a lower body fat percentage, and side sleepers with back pain because the material’s unique ability to conform to your physical characteristics means that you can experience greater pressure relief and contoured support to help maintain good posture and combat back pain.
Heavier weighted sleepers can also enjoy the pressure-relieving qualities of memory foam providing that the mattress is firm enough to stop you from sinking too far into the materials.
Latex foam mattresses are suitable for front, back, and side sleepers with back pain who may also sleep hot, sweat at night, and/or suffer from restlessness because natural latex tends to be more breathable and able to recover faster than memory foam for better mobility and temperature regulation – as long as the mattress has the right level of firmness relative to your body weight.
Polyfoam mattresses tend to be better for lighter and average weighted sleepers with back pain because polyfoam tends to not be as dense and durable as memory foam – meaning that it could wear out faster under heavier weights and lead to sagging that may make your back pain worse.
2: Support – Crucial For Good Posture and Preventing Pain
The quality of support that the lower layers of your mattress are able to provide is critical in helping to prevent back pain because whilst the firmness of the mattress influences the surface tension – and thus the level of pressure relief and the support to some extent – it’s the thicker support core that’s primarily responsible for holding your body weight and maintaining ideal posture.
Here’s a breakdown of the different types of support cores that you’ll typically encounter and what they can mean for your back pain:
Mattresses with a spring core have excellent potential for supporting your body weight to guard against back pain – especially for heavier weighted sleepers – if you opt for individually wrapped pocket coils with a firmer coil gauge of less than 13 (as opposed to an open coil mattress with a coil gauge greater than 13).
Mattresses with a foam support core are typically better suited to lighter weighted sleepers because heavier weighted sleepers may sink too far into the materials and end up with back pain – although this may not be the case in firmer mattresses.
Mattresses with zoned support can be very beneficial for all sleeper types with back pain because the support is more concentrated around the hip and lower back regions whilst the shoulder area has more ‘give’ to reduce the pressure points.
3: Layer Design – Influences Comfort and Support
The way in which the layers of the mattress are designed can influence how the firmness of the mattress is perceived – especially when you have back pain because even subtle differences can be felt vividly.
The upper ‘comfort’ layer of the mattress ties heavily to the level of firmness and also influences the rate of compression and pressure relief that you’ll experience.
Whilst the lower ‘support’ layer is dominant in its role of providing support – with some mattresses also having an additional ‘transition’ layer sandwiched between these two layers to stop you from sinking into the support core below and potentially making your back pain worse.
Here’s a breakdown of how you can expect the layering design of different mattress types to potentially influence your back pain and comfort levels:
All-foam mattresses can potentially be suitable for all sleeper types if they are selected in the correct firmness, but heavier weighted sleepers may find mattresses with foam in both the comfort and support core to sink in too much, be harder to move around in, and possibly make your back pain worse.
Conversely, lighter weighted sleepers are the most likely to benefit from an all-foam mattress in the correct firmness because the greater capacity for material compression can help to dissipate pressure and help you to maintain good posture.
Restless couples with back pain can also benefit from an all-foam mattress in the right firmness because in addition to the foam soothing pressure points to reduce night-time waking, the foam does an excellent job of absorbing shock waves so that you don’t wake each other up as you move around.
Hybrid mattresses are arguably the best types of mattresses for all sleepers and especially those with back pain because the coils in the support core work with the foam in the comfort layer to provide an excellent balance between pressure relief and support for an individualized sleeping surface.
Traditional spring mattresses are a cheaper alternative for those with back pain but may not last as long as a high-quality hybrid or even an all-foam mattress which means that the mattress may wear out faster and make your back pain worse.
Conclusion: Take a Holistic Approach
Whilst the opinion of your doctor should take precedence over anything that you read online, you should holistically consider the firmness, materials, and layering design to give you the best chance of finding a mattress that can help to combat your back pain.
If you’re ready to buy a new mattress, then click the button below to see the best mattresses and adjustable beds for back pain to buy now.
Sources and References
 Science Direct – Effects of an Adapted Mattress in Musculoskeletal Pain and Sleep Quality in Institutionalized Elders. Accessed 21/11/10.
 Health Line – Is Sleeping on the Floor Good or Bad for Your Health? Accessed 21/11/20.
No part of this article or website is intended to provide medical advice – always consult with a qualified medical professional if you require such guidance.
Image Attribution and Licencing
Main Image – ‘Woman With Back Pain Sitting on Bed’ by AndreyPopov (Getty Images), used with permission under Canva’s One Design Use License Agreement.
Dan is the founder and head content creator at Bedroom Style Reviews.
He has been working as a professional online product reviewer since 2015 and was inspired to start this website when he ended up sleeping on a memory foam mattress that was too soft and gave him backache.
Through in-depth research and analysis, Dan’s goal with this website is to help others avoid such pitfalls by creating the best online resource for helping you find your ideal mattress, bedding, and bedroom furniture.
Dan is a qualified NVQ Level 2 Fitness Instructor with 6 years’ experience helping clients improve their health through diet, exercise, and proper sleep hygiene.
He also holds several college and university-level qualifications in health sciences, psychology, mathematics, art, and digital media creation – which helps him to publish well researched and informative product reviews as well as articles on sleep, health, wellbeing, and home decor.
Dan also has direct personal experience with insomnia, anxiety, misophonia (hypersensitivity to sounds), and pain from both acute and long-standing sporting injuries – he enjoys writing insightful articles around these subjects to help fellow sufferers of such conditions.
Learn more about Dan here.