This chapter review about Hydrostatic pressure (Fluid motion, Laminar flow, Turbulent flow), Atmospheric pressure (Torricelli’s experiment, Pressure notation in medicine), Aneroid barometer, Gas pressure (Boyle’s law, Charle’s law, Gas equation, clinical application), Osmosis, Measurement of pressure in the body (Arterial and venous blood pressure, sphygmomanometer, Ocular pressure, Intracranial pressure) and Application of pressure in nursing (limb edema, respiration, respirator, autoclave, Blood gas analyzer, Venturi meter, Bunsen burner, pressure relief valves, pressure reducing valves).