Sitting for long periods of time has emerged as a significant health threat, associated with everything from obesity to metabolic syndrome, which can include high blood pressure, and high blood sugar and cholesterol levels.
More companies and individuals are taking steps to reduce sitting time by moving to standing workstations, which have surfaces at heights that allow the user to stand while typing on a keyboard and viewing a monitor.

Full article: The (ergonomically ) right way to set up a standing workstation
Source: Safety Best Practices