Abstract Limb tourniquets are commonly used to help facilitate surgery by producing less blood in the surgical field. This may also shorten operative time and reduce intraoperative blood loss. These advantages need to be weighed against potential complications such as post-tourniquet syndrome, skin damage, deep vein thrombosis, rhabdomyolysis and ischaemic pain. Physiological changes in the cardiovascular, respiratory, metabolic, haematological and neurological systems also occur.