The patient repeatedly has trouble getting to sleep and trouble awakening on time. Jet Lag Type. Alertness and sleepiness occur at inconvenient times of day after traveling across more than one time zone. Shift Work Type. Because of night shift work or frequently changing job shifts, the patient experiences excessive sleepiness during major periods of wakefulness or insomnia during major sleep period.
Some disorders display similar or sometimes even the same symptom.
The clinician, therefore, in his diagnostic attempt has to differentiate against the following disorders which one needs to be ruled out to establish a precise diagnosis. Circadian Rhythm Sleep Disorder is a mismatch between a person's internal sleep-wake cycle and external demands. In a sense, it is not a disorder, because there is nothing unusual about the person, except perhaps more than normal difficulty in shifting the cycle of sleep and waking. Nevertheless, the mismatch creates periods of insomnia, sleepiness, or both, depending on the time of day and how much time the person has to make up for the insomnia. Only in severe cases of disruption would a person with this type of difficulty seek treatment.