Cheyne-Stokes respiration (CSR) is a breathing pattern cycling between apnea (temporary breathing cessation) and hyperpnea (rapid and deep breathing). It is associated with neurological monitoring of blood carbon dioxide levels. Clinical researchers hypothesize that fluid shifts in the body when changing from an upright to a recumbent position are a factor involved in the onset of CSR. A model of CSR that incorporates body fluid shifts fit to clinical measurements is presented and analyzed. In agreement with clinical knowledge, the model predicts increased likelihood of CSR for males over females, and for patients in the supine position over upright.