Phase equilibrium and kinetic models for describing the swelling of hydrogels are considered. The swelling equilibrium model is based on an effective Flory-Huggins model coupled with a phantom network model in the framework of the Flory-Rehner theory, The kinetic model used is that proposed by Camera-Roda and Sarti, which is capable to describe non Fickian diffusion that occures in hydrogels. The models are coupled and applied to non charged thermo-sensitive hydrogels and the results obtained show a good agreement between experimental and calculated data.