An implantable, body-driven shunt pump includes a pump body defining a fluid inlet, a fluid outlet and a fluid chamber therebetween; an inlet valve arranged in the fluid inlet, the inlet valve being a one-way valve arranged such that it is operable to allow fluid flow into the fluid chamber and to prevent fluid flow out of the fluid chamber; and an outlet valve arranged in the fluid outlet, the outlet valve being a one-way valve arranged such that it is operable to allow fluid flow out of the fluid chamber and to prevent fluid flow into the fluid chamber. The pump body includes an expandable and contractible component in a portion of the pump body that defines the fluid chamber such that the fluid chamber changes volume in response to a change in pressure of fluid in the fluid chamber.