In dentistry, the hydrodynamic or fluid movement theory is one of three main theories developed to explain dentine hypersensitivity, which is a sharp, transient pain arising from stimuli exposure.

In fluid dynamics, hydrodynamic stability is the field which analyses the stability and the onset of instability of fluid flows.

In atmospheric science, hydrodynamic escape refers to a thermal atmospheric escape mechanism that can lead to the escape of heavier atoms of a planetary atmosphere through numerous collisions with lighter atoms, typically hydrogen.