Choosing a mattress
The mattress for the comfortable user
The mattress is a personal thing. It's like shoes. Just as shoe size is strictly related to the size of the sole, the mattress is strictly related to the height, weight, constitution and health issues of whomever sleeps on it.
The purpose of a mattress is to provide support and comfort to the people who sleep on it. The support comes from bottom layer of the mattress, and the comfort comes from the top layer.
The relevant factors in deciding what mattress to choose are: your body type and particularities, your health particularities, your budget, the quality of the mattress. The mattress type (springs, latex, or memory foam) isn't such a factor.
It can not be stated more firmly (pun intended) that the saying "a firm mattress is good for the back" is an evil advice which should only be given to enemies. If you are slim then you should choose a soft-firmness mattress, if you are average to fat then you should choose a medium-firmness mattress.
According to Huelsta, the firmness of a mattress should be chosen based on the BMI of the person who sleeps on it:
You can find a BMI (Body Mass Index) calculator here.
To choose a mattress, go to the store, lie in your preferred positions on as many mattresses as you like, stay there for as much time as you can, and buy the one that feels best for you and that you can afford to pay without living your life to pay for it. When testing, follow the advice below.
Is lying for a few minutes on a mattress a guarantee that you will make a good choice? No, but not lying on a mattress at all is more likely to lead to choosing a wrong mattress.
When laying on your back, your bottom and the middle of your back have to push in the mattress, and your head has to push in the pillow, all without causing pressure / pain to your bottom, lower back, middle of your back and neck; "middle of back" is about at nipple level, where the backbone is curved the most outward.
When laying on your side, your hip and shoulder have to push in the mattress, and your head has to lie on the pillow, all without causing pressure / pain to your hip, lower back, side chest and neck; "side chest" is about at nipple level.
You must use a pillow which fits both your body and the mattress that you are lying on. Try multiple pillows with the same mattress.
If while you relax on a mattress you start to feel sleepy after a few minutes, the mattress is a good candidate for the final decision.
Do this several times, weeks or even months apart, so that your body and mind adapt to all the mattresses.
A mattress should have:
According to this survey, the general opinion is that the highest owner satisfaction is for memory foam (81%) and latex (80%) mattresses, while the lowest is for spring (64%) mattresses.
When you consider the cost of a mattress (and of any accessories), think at the price that you are willing to pay each month for a mattress which will literally have your back.
You will probably change your mattress every 5 to 10 years, maybe with an average of 7. There are 7 * 12 = 84 months in that period, so multiple this with the amount of money that you are willing to pay each month. This should be the maximum price of your mattress.
See this for a way to determine if you can afford things in general.
Hygiene studies for different types of mattresses are conflicting, so don't choose your mattress type based on hygiene claims for that type.
For example, this study has found that foam mattresses contain more dust mites than spring mattresses. However, the authors recognize that another study has reached the opposite conclusion.
Foam firmness is described using a standard measurement value called IFD (Indentation Force Deflection), and is the number of kilograms of force required to indent a foam sample by a specified percentage (usually 25%) of its original thickness.
For example, to measure IFD, a 20 cm (= 8 in) metal disc presses a 10 cm (= 4 in) thick sample of foam until a 2.5 cm (= 1 inch) high indentation is created. The force in kilograms required to obtain this indentation is the IFD.
Lower IFD numbers indicate a softer foam, while higher values indicate a firmer foam.
The compression modulus (also called "support factor") is for IFD what acceleration is for speed.
The compression modulus is determined by dividing the IFD required to obtain a 65% tall indentation in the foam, to the IFD required to obtain a 25% tall indentation in the foam.
A common compression modulus for high quality foams is 2.5. This means that the firmness of the foam is higher the more it is compressed.
The surface firmness (at 25% tall indentation) shows the comfort feel of the foam, while the deep firmness (at 65% tall indentation) shows the support feel of the foam for the body (that is, the foam's ability to prevent the body from reaching the bottom of the mattress).
A foam's density is independent from its firmness, except for latex where they are proportional. High density foams can be produced to be very soft, and low density foams can be made to be very firm.
A high density foam is more durable than a low density foam.
Density directly affects the comfort, support and durability of foam.
A common density for memory foams is at least 50 kg / m3 (3 lbs / ft3).
Memory foam (also called viscoelastic foam) is a foam which slowly reacts to heat in the sense that it slowly deforms to take the shape of a body which sits on it, slowly recasting itself to the shape of the body, and slowly regaining its factory cast shape once the (heat of the) body moves away. As the body moves on the mattress, the memory foam slowly adapts to the new position of the body, not instantly like in non-memory foams.
Memory foam is normally used only for the comfort layer because it lacks supportive properties (= has a low compression modulus).
People who first try a memory foam mattress may find its embracing to be unpleasant. When the memory foam takes the shape of the body, the depression which occurs in the mattress may be too deep (depending on how thick and reactive the memory foam is). Because of this depression formed under the body, moving around and getting up from the mattress requires more effort than on a non-memory foam mattress.
This gives a feeling of being in a caught in a whole (in the ground). However, after a few weeks the body adapts to the new feeling and it starts to enjoy the stability.
Not all memory foams are equal. Some react more intensely than others at the same amount of heat. As the reaction to heat increases, so does the heat retention of the foam, and heat retention is unpleasant in a warm environment. Tempurpedic mattresses are known as having the highest memory effect, but also the highest heat retention. I had a Tempurpedic (memory foam) pillow which made my nape sweat during the summer, but my current Magniflex (memory foam) pillow only feels warm (but not hot).
Humidity, either from the air or from perspiration, is absorbed by memory foam, which causes it to sag.
Bounciness and stability
The slowness with which memory foam reacts when exposed to heat, both when deforming and when regaining its factory cast shape, leads to a lack of bounciness, and this provide an exceptional stability to the body during sleep.
Springs, latex, and non-memory foams have bounciness, that is, once the body moves on them they instantly change their shape. This leads to muscular activity and body movements to find a stable position, especially for side sleepers, and this results in a less deep sleep. Something similar happens if the mattress or pillow is too soft or too firm.
The lack of bounciness of memory foam affects sex because thrusting has no feedback / bounciness.
A memory foam mattresses is not a mattresses made entirely from memory foam, but a mattresses which has a significantly thick memory foam layer on top, like 5...15 cm (2...6 inches) thick.
This is because memory foam is very expensive, but also because while it provides good comfort, it doesn't provide good support for the body (because it has a low compression modulus).
Memory foam is better for the back
There are two factors which deform a mattress:
When you lie on a non-memory foam mattress:
Since memory foam is also deformed by heat (not just weight), no matter what the firmness of the foam is, the memory foam doesn't push back into your lower back.
The same happens in the case of the head and neck on a pillow.
There are mattresses with several zones of different levels of firmness. However, these zones are fixed in size, position and firmness, so they are unlikely to fit your body's height, structure and sleeping positions. It's especially bad when there are more than 3 zones because it's very easy for you to lay on the zones which are the opposite of what you need.
On a mattress without zones, your body pushes differently into the mattress, depending on the weight of each body part, preserving your backbone's natural curve. Also, on one hand, your bottom must not sit on something too firm because that would keep it too high for the lowest part of your back to preserve its natural curve, and on the other hand, if your bottom sinks in the mattress too much then you need a firmer mattress. In any case, you don't need a mattress with multiple zones.
Heat retention is body heat which is retained by a mattress when you lie on it; because this heat is not absorbed by the mattress, it creates a discomfort by overheating the person who lies on it.
Foam mattresses are generally affected by this problem, with memory foam mattresses being affected the most. Heat retention is in fact the biggest disadvantage of memory foam mattresses, toppers and pillows.
The more your body sinks in a mattress, the less ventilation exists and the more heat is retained by the mattress.
Heat retention can be reduced during the manufacture process by reducing the memory effect, or by drilling narrow, vertical tubes through the mattress.
Heat retention can be reduced by sleeping on a mattress cover made with bamboo fibers.
If you feel that your mattress retains heat, you could try to sleep with very thin pajamas or none at all, and cover yourself with only a sheet (not a blanket or duvet).
Spring mattresses are theoretically immune to this issue since they are mostly empty around the springs. However, modern spring mattresses have a foam layer at the top, layer which blocks the ventilation and retains heat.
Latex is a rubber with excellent elastic properties, which can be used for both the support and comfort layers.
In order to benefit from the properties of latex it should be used for both the support and comfort layers, so avoid buying a latex mattress if the height of the latex layer is less then most (for example, two thirds) of the height of the mattress.
There are manufacturers which have mattresses that have separate foam layers which can be swapped to provide you the firmness that you need.
There are manufacturers which have mattresses that are split in half, one half for each person that sleeps on the mattress. You can unzip the cover of such a mattress and expose its internal foam layers. You can then flip over either half (or even both), so that each person has a half-mattress with a different firmness than the other person. The foam layers are usually glued together, so you can't swap them around.
In order for the two halves to feel as a single mattress rather than two smaller ones, the mattress cover has a foam padding layer which is thick enough to bridge the gap between the two halves.
If you think that this padding is not enough, it's possible to buy a mattress bridge. A mattress bridge is a filler plank made from a soft material, which is put in and above the gap between two mattresses, under the cover.
A split mattress also gives you the possibility to replace only half of it at a time. For example, you can start by buying a 180 * 200 cm (72 * 80 inches) mattress; later you can replace half of it by buying a 90 * 200 cm (36 * 80 inches) mattress (and taking its cover off).
A split mattress is important for people who sleep together and have significantly different physical constitutions, but also for people who either sell or rent an apartment / house which includes the mattress.
There are various types of bed foundations: solid plank, plank with many small holes all over it, wood slats, springs.
A bed foundation made made from a solid plank is a bad choice for any kind of mattress because it blocks any ventilation.
A bed foundation made with springs is meant to complement a relatively thin mattress with springs.
A foam mattress should be put on a firm bed foundation which has good ventilation, like a plank with many small holes all over it.
A bed foundation should allow you to lift the mattress with ease, so make sure that the mattress handles are not covered, or that you have space which allows you to lift the mattress.
The top of the mattress should be high enough so that you can get down from the bed rather than get up from the bed, that is, you should not need to force your knees to raise your body from the bed. An average height is 60...65 cm (25 in).
The pillow is as important as is the mattress itself, and should only be chosen in pair with the mattress.
A pillow should be made from memory foam in order to provide stability (not bounciness) to the head during sleep.
There are memory foam pillows which are solid blocks of foam, but there are some which imitate feather filled pillows (and which contain shredded memory foam).
When searching for a pillow to buy, you should start with a wavy pillow. Such a pillow is designed to have its middle thinner than the sides. This allows the head to sink in the pillow more than the neck, and so the head, neck and backbone stay straight in line. Usually, the sides of the pillow have different thicknesses so that if one of them doesn't fit your neck, the other might.
A little story about bouncy-foam pillows
For about 8 years I have slept on a latex pillow. The pillow was great, it had no irreversible deformations; it only got a little yellow and a bit more brittle.
From some point onward, occasionally, I started having extreme neck pain manifesting as hot stabbing flashes when I was turning my head. If the movement was very slow, the pain was reduced significantly.
After 8 years I've replaced this pillow with a memory foam pillow. The pain virtually disappeared.
I tried again the latex pillow and the pain reappeared the next day. I then realized that the latex was pushing into my nape, so this may have been the cause of the pain. Another possible cause was that the bounciness of the latex was forcing me to turn my head in order to find a stable position, turning which led me to sleep with my neck twisted.
The odd thing was that the latex pillow was much more comfortable than the memory foam pillow when I put my head on it, yet it had an invisible opposite effect on the long term.
I've repeated the experiment with a pillow which had one half made of memory foam and one half made of bouncy foam, and the result was the same: when I was sleeping on the bouncy part, the pain reappeared.
The moral of the story is that if you have neck, back, hip, shoulder or even knee pain, be sure to pay attention to how you sleep, on what you sleep and what is the position of your body for long periods of time on the bed, sofa, chairs, and even toilet (if you sit for long times on it).
For instance, if you sleep of your side on a firm mattress, the hip on which you usually lie may start hurting.
Lower back pain can occur because you sit the wrong way on a chair, like with the sole of a foot on the chair, therefore forcing your backbone to bend laterally.
Sitting with the calf or ankle of one foot over the knee of the other (which rests on the floor) may cause pain in the calf of the foot which is resting on the floor.
The biggest problem in understanding the cause of your problems is that the pain may occur much later than the cause. For instance, you may be sleeping in a bad position, but the pain may start occurring only years later.
You could also think that back or neck pain is age related even though it may be your bad mattress / pillow, mattress / pillow which you may be accustomed to and say that it's a good one. Being accustomed to it doesn't mean that it's good for your body (even if it's comfortable).
Avoid sleeping on your stomach because this position puts great pressure on your neck due to the fact that you need to keep your face turned 90 degrees relative to your backbone (in order to be able to breath).
Generally, the user satisfaction increases as the thickness of the mattress increases. For the average adult, the thickness of a mattress should be at least 20 cm (8 inches).
Your mattress must have a firmness which fits your body, and must not be sagging, that is, it must not have permanently depressed areas (especially where your bottom is).
If your back or neck hurts, it may be that your mattress is bad, or that your sleeping position is bad. You have to sleep with your body straight. If you are used to sleep on your side, the mattress has to be soft so that your hip and shoulder can easily sink in it and therefore allow your backbone to be straight. The way you sit on chairs may also be a cause of back or neck problems; you have to sit with your back and neck straight and with your soles on the ground.
A mattress topper should have 5 to 10 cm (2 to 4 inches). More than this would give you an unpleasant sinking feeling because a topper is made to provide comfort, not support to the body.
If you use separate mattresses for each person, you may feel the separation between them even if you use a mattress topper. In this case you can use a mattress bridge.
You should buy a mattress only if it has a removable cover so that you can see the layers inside, see what they are and how clean they are.
You should always use a mattress protector (which is like a moisture resistant sheet) to protect the mattress from body humidity.
Oeko-Tex 100 is a certification for the chemical safety of textiles for people.
If you want to sleep well and feel relaxed in the morning then remove stress from your life, do physical exercise, eat properly, and sleep 7...9 hours a day (depending on your body's needs); "sleep" means sleeping, not just laying (consciously) in bed. The muscular tension created by stress can't be reduced by a mattress, no matter how expensive.
I've heard that brand X makes super-mega-ultra great mattresses that make you fall asleep in the showroom as you try one, and have features Y, Z and W that I've heard I really need. Should I buy one?
You know what mattress is good for you? The one that you lie on, and out of the tens that you've tried feels the best to you, fits in your budget and has a warranty which fits your needs (if the manufacturer fulfills that warranty, especially for its inner layers). Keep in mind that, usually, the lifespan is much shorter than the warranty, and it's generally between 5 and 10 years; make sure that you read this about warranties and lifespan.
Everything else is marketing.
Oh, and choose to buy from a manufacturer which describes in as much detail as possible the internal structure of its mattresses, and the materials that they use.
How can I ensure that a mattress has Oeko-Tex certification?
Textile manufacturers and their products can have Oeko-Tex certifications. These certifications are different things.
To be certified, a mattress must have a label (with green, orange and black text) stitched on it, label which represents the Oeko-Tex certificate. This label contains the text "Confidence in textiles". If the label contains the text "0904046.O", it means that the mattress is class 2 certified, meaning that it's not expressly certified as being safe for babies.
Oeko-Tex says that in order to get their certification it's required that all the components of an item meet the required criteria without exception (meaning, the outer material, sewing threads, linings, prints, buttons, zip fasteners, rivets).
If you want to verify that a manufacturer is not falsely attaching an Oeko-Tex label to their products, verify that their name is on the Oeko-Text website.
Sleep Like the Dead = Information about anything related to sleep, review aggregations.
John Ryan = See their guides about the mattress construction and industry.
Casper = Sell mattresses through the Internet, which allows them to avoid paying some costs, so they say that they have much lower prices than in a showroom, at the same quality.
Tuft and Needle = Sell mattresses through the Internet, which allows them to avoid paying some costs, so they say that they have much lower prices than in a showroom, at the same quality.
DreamFoam = Have mattresses that are split in two halves which can be turned independently.
Magniflex = Have mattresses that are split in two halves which can be turned independently. I have verified their Oeko-Tex certification (though, sadly, not helped by the manufacturer), using the manufacturer's name, not the brand name. Their mattresses come with a class 2 certificate.
Sleep by Number = Have smart mattresses which use electronics to monitor who sleeps on them, and to adjust their firmness.
Rest Performance = Have smart mattresses which use electronics to monitor who sleeps on them, and to adjust their firmness.