Sexuality is a sensitive topic in health care and is often interpreted through a natural scientific lens as just corresponding to sexual dysfunction and fertility problems. The purpose of this thesis was to describe sexuality and its outcomes in two cancer populations. Women with breast cancer and men with prostate cancer in all stages were invited to participate. In this thesis, these two populations are restricted to age groups between 45 and 65 years, since there are reasons to believe that younger people are more vulnerable to sexuality changes. Lifeworld, gender, and sexuality are three concepts of importance in this thesis and they are used from the viewpoint of nursing care. Phenomenological interviews (I, III) and focus group interviews (II, IV) were carried out with a total number of 46 informants. The EPP-method (Empirical Phenomenological Psychological) was used (I, III) in order to grasp the lived experience, and qualitative content analysis was used to analyse the seven focus groups (II, IV). The lifeworld experiences of those women and men were comparable. The changes brought by the cancer and its treatment were a threat to their very existence, their existential base of knowledge had gone and alienation occurred (I, III). For the women, this was illustrated through the metaphor of a bird which is pinioned and unable to fly anymore. For the men it was expressed in the essential meaning “to lose the elixir of life”. Both women and men suffered, sexuality changed from one day to another and they handled it individually. Changed body appearance, and feeling old and unattractive were, for the women, the dominating features, whilst for the men changed desire and erection problems were their main concerns. The findings from the group discussions (II, IV) elucidate the gendered differences in these two contexts. The aim of the women was to look healthy and attractive and for the men the ability to have an erection was important. Neither of these two groups of people was able to meet their aims. On the other hand, being diagnosed with a life-threatening disease they were not in a position to claim preserved sexuality. This opens up existential questions that need to be confirmed in health care. To succeed in this, a change of perspective is required in health care. It should be possible to use human science to the same extent as natural science in health care.