Firmness and support are related but separate factors to consider when choosing a mattress. Mattresses that are too soft for your body will not offer the correct amount of support, but choosing a firmer mattress doesn't necessarily mean it will be more supportive. In fact, an overly firm mattress can be unsupportive if it interferes with the natural curve of your spine. To determine the best firmness for your needs, take your weight and preferred sleep position into account. Rather than increasing your mattress firmness past this level, consider a bed with a robust support system — such as an ergonomically zoned hybrid mattress — if you require more support.