Patients with bipolar disorder are mainly characterized by high or easily provoked mood, increased speech and activity, and high energy levels during mild manic or hypomanic episodes. As for sleep, it is common to have a reduced need for sleep, with only 3-4 hours of sleep per night being sufficient to remain energized during the day. However, some patients with bipolar disorder have a strange cyclical sleep pattern, which is seldom noticed by the patients and often leads to a delay in consultation. Case 1: A 37-year-old woman came to the clinic with the main symptom of “not being able to sleep 1/3 of the time every month (insomnia), 1/3 of the time not being able to wake up (narcolepsy), and 1/3 of the time sleeping normally”. After careful questioning, the patient recalled that for many years in the insomnia during the mood “hyper”, energetic, active, high efficiency; and sleepiness during the low mood, more bedridden reluctant to go out, often take sick leave to rest. The patient did not pay much attention to this cycle of illnesses over the years, and it was not until a sick colleague suggested it that she received treatment. The patient is currently thinking about getting pregnant, but now she will have to complete treatment before she can think about getting pregnant. If she had realized earlier that she needed to be seen for sleep disorders, she could have completed the treatment cycle earlier and not delayed her pregnancy planning for an older woman. Case 2: Another young man, aged 25, recalled that he had a cyclical sleep cycle since junior high school, with a pattern of “depressed mood (insomnia) – “hyperactive” mood (normal sleep) — normal mood”, but did not pay attention to it, so it lasted for many years until the condition worsened before seeking medical attention. Case 3: A middle-aged female patient in her 60s, who has suffered from bipolar disorder for decades and has been taking mood stabilizers for years, still feels that she is prone to “depression” only in the spring, fall, and winter seasons, and denies that she has a problem of (mild) mania. The patient was able to clearly describe his performance during depression as “unable to get up, not wanting to move, unwilling to talk, able to sleep for several days in a row, no energy, and difficulty in seeking medical attention”; and he thought that his performance during the hypomanic episodes was “very normal, quite happy”, and the only change he admitted was that he was “very happy”. The only change he admitted was that he “could get out of bed and didn’t need to sleep as much”. It can be seen that all of these bipolar patients had sleep abnormalities during the fluctuations of their illnesses, but the patients tended to ignore the changes in their moods and only noticed the changes in the form or quality of their sleep. For some patients who do not realize that their (mild) manic manifestations are abnormal, timely consultation for sleep-related reasons would provide a valuable opportunity for timely diagnosis and treatment. It is recommended that if patients or their families find themselves or their loved ones in similar situations, they should consult psychiatric hospitals in a timely manner and be highly alert to the possibility of “bipolar disorder”.