Abstract Medical knowledge of HIV is rapidly evolving, leading to increased understanding of the disease, its immunology and clinical manifestations. Combination antiretroviral therapy (cART) has provided a means of controlling but not curing the disease and patients now live longer, healthier lives with the disease. However, new challenges are emerging, including those of treating a population ageing on antiretroviral therapy, and continuing to prevent transmission of the virus. Worldwide, strategies including universal testing and the rollout of cART have reduced transmission and the number of new diagnoses is falling. However, in the UK approximately one in four patients with HIV are unaware of their diagnosis and nearly half present with a CD4 count lower than 350 cells/μl. It remains essential that all healthcare providers are alert to those at risk of HIV, or who display the signs of early infection, to ensure these patients are tested and treatment is put in place before the development of HIV-related infections, cancers and complications.