Active and passive retinal water transport mechanisms must be altered to cause an exudative detachment (ED). The retinal pigment epithelium (RPE) plays a critical role. Whenever the RPE pump becomes dysfunctional or its adhesive force is overcome, ED can follow. ED can occur in the presence of reduced pump function with excessive traction as can occur diabetes, retinal detachments (mainly pseudophakic) in the absence of a tear, or certain inflammatory disorders such as pars planitis. Thickened subretinal fluid can compromise the RPE pump as is seen with persistent serous detachments following buckle surgery. However, most cases are due to a generalized depression of the RPE pump coupled with excessive fluid influx - idiopathic and steroid related central serous retinopathy, age related macular degeneration, idiopathic polypoidal vasculopathy, retinal vein occlusion, uveitis (sympathetic and VKH). Treatment will depend on the cause - may include an attempt to stimulate pump function or the elimination of tractional components. In many cases, identifying the presence of an ED leads to a conservative follow-up with excellent outcomes.