A patient’s journey with cancer may cause psychological disorders or exacerbate existing conditions. The field of psycho-oncology has found ways to link psychological disorders to cancer and research the effects of mental disorders on patient outcome and wellbeing. This review looked at current literature in the field of psycho-oncology to understand how the stress level changes during the patient’s treatment journey. A search was performed to identify relevant published articles on electronic databases, including PubMed, ScienceDirect and Web of Science. The results demonstrate a direct link between cancer diagnosis and increased stress, depression and anxiety within patients, not as medication side-effects. These levels reduce over time, mainly due to patient acceptance coupled with either improved prognosis, or acceptance of death. Stress is complex and can precipitate a range of psychological disorders. Early psychological, counselling and even in some cases coaching interventions, could work preventively to help cancer patients more effectively to manage their stress, thereby promoting their greater wellbeing. Additionally, early diagnosis of mental disorders is crucial to improving long-term outcomes, therefore, the need for adequate psychological screening services in oncology patients for mental illness should be routine practice