System for monitoring the hydration status of a living being by exploiting the modulation of backscattered RF electromagnetic waves from a wearable patched placed on the skin, said system comprising:a RF-tag adapted to be directly or indirectly fixed to the skin and containing at least one passive integrated circuit coupled to an antennaan electromagnetic RF power source for supplying different signal frequencies to said RF-taga reader adapted to receive and to process the backscattered electromagnetic waves generated by said electromagnetic power source.
