a height - adjustable pillow for supporting a patient &# 39 ; s head . the pillow includes a casing of flexible material defining a casing volume and a volume of filler material partially occupying in said casing volume . the casing volume is compressible and expandable . the casing volume includes a support portion positioned above a base portion . an air valve is associated with the casing for introducing air into and evacuating air from said casing volume .