There are four basic requirements for a good mattress to enhance a healthy sleep. In order of importance: Maintain Spinal Alignment, Reducing Surface Pressure, Regulating Body Temperature, and Resist Nasty Allergens.

• Maintaining Spinal Alignment On a Mattress:  Mattresses and bed bases that do not support your spine produce backaches. The ideal position of your spine while lying on the mattress or bed is the same as it while standing. A mattress that is too hard will tend to put pressure on your shoulders and hips while not supporting your lower back or side. Soft mattresses often sag, causing your spine to follow the curve of the mattress. Only a mattress that can conform to your body without sagging will give adequate support. This support should be felt evenly along the length of your body while sleeping on the mattress, especially at your waist and lower back.
• Reducing Surface Pressure: High pressure on your shoulders and hips causes tossing and turning because it restricts blood flow and eventually will cause these joints to ache. A good mattress that conforms to the shape of your body will distribute your weight evenly and eliminate high-pressure areas. This will allow your body to relax and reach the deeper levels of sleep, which ensure the highest level of body recovery. This pressure can be measured scientifically to assure proper circulation. One can also test this by lying on the side of the mattress and feeling the pressure on shoulders and hips.
• Regulating Body Temperature: Sleeping too hot or too cold will also cause tossing and turning on the mattress. While we sleep, our bodies give off moisture, which gets trapped in our bedding. This dampness interferes with our body’s ability to regulate its own temperature. The best cure for this is wool, either as the top layer of the mattress or in a separate mattress pad. Wool can absorb up to one third of its weight in moisture without feeling damp. It also dissipates moisture much faster than down, cotton, or polyester. Since you are drier, you are warmer in the winter and cooler in the summer. Your heartbeat actually slows down, and you fall into a deeper sleep on a bed.
• Reduce Harmful Allergens: Waking up with sinus troubles in the morning may indicate dust mites in the mattress, mould or mildew causing allergies. Some mattress materials are anti-microbial (such as latex), so that dust mites will not reside in these mattresses as easily as in others and these mattresses offer a certain protection for those who struggle with allergies. The cover of the mattress is also a key to overcome the allergy problem.