A medical device is disclosed which connects an overactive tissue suffering from positional displacement in a living body to a less active tissue having a range of movement smaller than that of the overactive tissue to correct the positional displacement. The medical device can include an elongated insertion tool including an observation portion configured to observe a distal end side of the medical device using an imaging device, and a guide portion configured to guide a treatment tool, which is to be used to carry out treatment for the less active tissue, to the proximity of the less active tissue, the insertion tool having a dissection function for dissecting a biological tissue when the insertion tool is inserted into the living body from the outside of the living body and advances toward the less active tissue in the living body.
