Experiencing and managing a long-term condition places heavy emotional demands on a patient or carer. We conducted disease-specific focus groups for patients or carers. We recruited adults with diabetes, heart disease or hepatitis C, parents of children with asthma or diabetes, and carers of people with Alzheimer's disease. Participants had sole access to a PC and were asked to use three Internet interventions, each for 30 min. We conducted 10 disease-specific focus groups in three areas of the UK, involving a total of 40 participants. Three main themes emerged from the data: dealing with negative emotions, boosting positive emotions and social support. Designers of Internet interventions should consider users’ emotional needs and how to meet these needs with every section or facility within an intervention.