Usually, patients are diagnosed by filling out a sleep log and showing it to a sleep specialist or a neurologist with a sleep specialty who is literate in Non-24. Non-24 Sleep–wake disorder is diagnosed when the patient fails to follow (entrain to) a 24-hour light-dark cycle and typical wake times.
This graph is an example of a Non-24 sleep pattern with a semi-predictable forward shift. The date is horizontal and the sleep time is vertical. It shows a semi-predictable pattern and then shows the patient forcing themselves to stay awake on 2/25; then, the pattern tries to correct itself to the patient’s abnormal (Non-24) circadian rhythm.
For information on keeping sleep logs, visit our Resources page.