Phobic reactions to receiving or self-administering injections reduce the ability of patients to comply with some medical or dental treatments and can lead to the avoidance of medical care. The growing number of injectable medications available has increased the impact of injection phobia on the successful delivery of healthcare, although the effect on long-term health outcomes is not clear. Underlying mechanisms may involve genetic and psychological components. Effective treatment involves cognitive behavioural therapies (e.g. exposure and cognitive restructuring) and relaxation techniques.