Delayed sleep phase pattern is a disorder in which an individual has a circadian rhythm that is shifted later than normal. This results in difficulty falling asleep at a desirable time and difficulty waking up in the morning. The disorder is often referred to as delayed sleep phase syndrome or delayed sleep-wake phase disorder. Other synonyms for the term include delayed sleep phase type, delayed sleep phase disorder, circadian rhythm sleep-wake disorder, and DSPD. While there are various treatments available for the disorder, such as bright light therapy and melatonin supplements, it is important for individuals with DSPD to consult with a healthcare provider to determine the best course of action.