Liberal fluid intake is one of the key management strategies in sickle cell anaemia (SCA) patients in steady state, but less work has been done on the desire of patients to drink water. Using the Visual Analogue Scale we studied thirst perception (TP) in 20 euhydrated SCA patients and 28 control (HbA) subjects, as well as during dehydration in 13 SCA patients and 9 HbA subjects. Serum and urine samples were collected and analyzed for Na, K ions, creatinine concentrations and haematocrit and specific gravity of urine were determined. During euhydration, TP was significantly [P