A system and related methods and components for treating a tissue site exhibiting interstitial hypertension, including tissue swelling, and particularly swelling associated with cerebral edema, compartment syndrome, and congestive heart failure, by the use of water removal therapy, in order to remove only water from biological fluids. Included also is a system for such use that incorporates one or more monitors, optionally in addition to the use of water removal therapy. By removing only water, all other biologic agents, including essentially all solutes and formed blood elements (such as cells) are increased in concentration in the remaining bodily fluid(s). WRT can be applied to several clinical conditions in which there is an excess of water, and is ideally used in an extracorporeal fashion, in combination with other functions and related components as well, including ultrafiltration.
