When you picture an older person, you may imagine someone shorter and slightly stooped. It’s not just your imagination: most of us gradually lose some height as we age. But how does it happen, when and by how much? Here’s what the science says, and when it can signal an underlying health problem. Most lasting height loss happens in the spine. Think of the spine as a tower of bony blocks separated by water-filled cushions. The blocks are the vertebrae, and the cushions are intervertebral discs.