Functionalized particles in the blood are able to selectively bind to targets in the blood that have adverse health effects. The binding of the particles to the targets allows the targets to be selectively modified or destroyed by energy from outside the body such that the adverse health effects are reduced or eliminated. The energy is generated by a wearable device which is able to direct the energy into the subsurface vasculature of the wearer of the wearable device. Further, one or more of the functionalized particles may be magnetic, allowing a magnetic field generated by the wearable device and directed into the subsurface vasculature to concentrate the bound targets in a lumen of the subsurface vasculature proximate to the wearable device.
