Evidence is emerging that disturbances in sleep and sleep disorders play a role in the morbidity of chronic conditions. However, the relationship between sleep processes, disease development, disease progression and disease management is often unclear or understudied. Numerous common medical conditions can have an affect on sleep. For example, diabetes or inflammatory conditions such as arthritis can lead to poor sleep quality and induce symptoms of excessive daytime sleepiness and fatigue. It has also been suggested that poor sleep may lead to the development of cardiovascular disease for which an underlying inflammatory component has been proposed. It is therefore important that the development and progression of such disease states are studied to determine whether the sleep effect merely reflects disease progression or whether it may be in some way causally related. Sleep loss can also have consequences on safety related behaviours both for the individuals and for the society, for example the increased risk of accidents when driving while drowsy. Sleep is a complex phenotype and as such it is possible that there are numerous genes which may each have a number of effects that control an individuals sleep pattern. This review examines the interaction between sleep (both quantity and quality) and parameters of cardiovascular risk. We also explore the hypothesis that inflammation plays an essential role in cardiovascular disease and that a lack of sleep may play a key role in this inflammatory process. Aim: To review current evidence regarding the endocrine, metabolic, cardiovascular and immune functions and their interactions with regard to sleep, given the current evidence that sleep disturbances may affect each of these areas.