A Mattress top is a usually a 2 to 3 inch piece of foam that is the same size as your mattress that you lay on top of your regular mattress to provide a more comfortable nights sleep. There are a variety of foams used for these mattress tops but the most popular type of foam is what is known as memory foam. Although different companies make their own version of memory foam they should all have certain features in common.The main two features that make memory foam mattress toppers different from other mattress tops is that this material fits to the contours of your body lending support to areas such as your lower back, neck and behind the knee area. It also springs back into shape when all weight is removed from it.Originally memory foam was first used by NASA and later in hospitals and the health field to help relieve pressure sores in bedridden patience. However, it wasn’t very long before different companies began to see a more widely used commercial use for the general public and different companies began to make their own version of Memory foam. Soon this foam was being used in pillows, chairs and for Mattresses and Mattress tops.Who Benefits From a Mattress Top Made From Memory Foam?The truth is almost everyone can get a more comfortable nights sleep having a mattress top made from memory foam. However, these mattress tops are especially helpful for people who are bed ridden as they help to prevent pressure sores as well as people with back, neck and other problems that need to have certain areas of their body given additional support that regular mattresses or mattress toppers simply don’t allow for.People with back problems who have slept on memory foam mattress toppers have reported being able to get a better nights sleep while experiencing little or no back pain or discomfort and waking up feeling more rested and with less pain.Various SizesMattress tops come in various sizes for twin, double, queen and king size beds. Memory foam mattress toppers are no exceptions and even come in sizes to fit futons and trundle beds as well. The cost of these Mattress tops varies depending on the size you purchase and the company who makes them.Where To Buy Mattress Tops Made of Memory FoamYou can purchase memory foam mattress toppers almost any place where mattresses tops are sold but, one of the best places to purchase this product is from Amazon.com. Not only does Amazon offer a wide choice in different sizes of these toppers, but they also offer memory foam by different companies giving you a larger choice than you might find locally.Since each company makes their memory foam a little differently this will allow you to read the reviews for mattress tops from different companies to find out which ones consumers find the most comfortable and longer lasting.A good memory foam mattress topper should not only be comfortable and help relieve those aches and pains but, should be durable enough to last 4 or 5 years if made correctly. Reading the reviews and seeing which brands are the most popular will help you make an informed choice about which mattress top might be right for you or your loved one.