Considerations of a person’s spirituality and/or spiritual needs are necessary in order to provide holistic and person-centred intervention within healthcare. However, the term “spirituality” is difficult to define clearly, so healthcare professionals are often unsure as to what exactly spiritual needs are, and also what their role is in addressing these. An in-depth literature review was therefore carried out in order to evaluate the various definitions: firstly, to evaluate how health professionals define spirituality, and, secondly, to explore the relationship between spirituality and health. The review revealed that spirituality is a highly subjective concept, with personal meanings and unique realities for individuals. Some people believe it involves recognition of a deity or a personal relationship with God, while others argue it can be defined simply as an expression of our truest selves or inner beings. Many prefer to use religious language in describing spiritual needs, thus supporting the inclusion of reference to the sacred or supernatural in any proposed definition of spirituality. Exploration of the concept of spirituality also uncovered its relationship to disability, illness, recovery, and health/well being. A working definition has emerged from analysis of the literature which is proving to be of use to healthcare professionals within their practice.