General systems theory is proposed as a framework for understanding chronic illness, and for intervention in chronic illness. It is suggested that chronic illness needs to be understood as a particular type of unhealth system. Various components of the unhealth system are described including disease, illness, sickness and illness behaviour, and applied to an understanding of chronic illness. The personal and temporal or developmental aspects of chronic illness are also described. The implications and value of a systems theory view of chronic illness are discussed and illustrated with two case demonstrations.Die Aigemene sisteemteorie word bespreek as 'n raamwerk waarbinne kroniese siekte verstaan kan word en intervensie beplan kan word. Kroniese siekte kan gesien word as 'n bepaalde ongesonde sisteem. Verskillende komponente van 'n ongesonde sisteem word beskryf onder andere organiese siekte en siek wees gedrag en dan toegepas op kroniese siekte om sodoende 'n beter beg rip hiervan te verkry. Die persoonlike en temporale of ontwikkelingsgang van 'n kroniese siekte word ook bespreek. Die implikasies en waarde van 'n sisteemteoretiese benadering tot 'n kroniese siekte word bespreek en toegelig aan die hand van twee gevallestudies.