There is a lot of confusion about whether or not all trundle beds raise up. The answer is, unfortunately, that it depends on the specific model. Some trundle beds do not have any mechanism for raising the bed up, and so they must be pulled out from underneath the main bed frame in order to be used. Other trundle beds have a hydraulic system that lifts the bed up so that it is at the same level as the main bed. It is important to check before you purchase a trundle bed to make sure that you are getting one that will meet your needs.