Post-natal depression is much discussed yet definitions and approaches are not homogenous, neither in terms of the cause of post-partum mental ill health, its treatment or how further research in the area should proceed. This paper seeks to examine post-natal 'upsets' and to consider the different explanations that have been and could be made of post-partum mental ill health. The paper reviews the dominant biomedical and psychological approaches, evaluating their ability to explain post-natal mental illness. The writer believes biological and psychological approaches are in the ascendance but seeks to demonstrate that they do not present a full picture. Sociological approaches drawing upon stress, labelling and feminist models are examined, exploring new ways of looking at post-natal illness. The paper concludes that biological and psychological approaches do not provide complete explanations and a multidisciplinary approach is needed. Most significantly the woman's own perception of post-natal ill health is largely absent from the literature. The need for an approach using ethnographic methods is highlighted.