All the biological systems can be treated as complex materials made out of multiple mechanical elements that give rise to intriguing properties such as elasticity and viscosity. By applying force and measuring the response to it (deformation) parameters like axial stress and strain, shear modulus, loss modulus or stress relaxation of tissues can be determined. During the presentation I`ll describe the methods to study rheological phenomena in living systems and explain how mechanical stresses can lead to mechanopathology and disease development in our bodies.