A sleep diary is a record of an individual's sleeping and waking times with related information, usually over a period of several weeks. It is self-reported or can be recorded by a care-giver. The sleep diary, or sleep log, is a tool used by doctors and patients. It is a useful resource in the diagnosis and treatment of especially circadian rhythm sleep disorders, and in monitoring whether treatment of those and other sleep disorders is successful. Sleep diaries may be used in conjunction with actigraphy. In addition to being a useful tool for medical professionals in the diagnosis of sleep problems, a sleep diary can help make individuals more aware of the parameters affecting their sleep. This data alone can help people self-diagnose what helps them get a good sleep.