<unk>  is mainly diagnosed via clinical interview and ruling out other potential sleep disorders that could account for the feelings of<unk> . Several measures are available to reliably diagnose or screen (Munich Parasomnia Screening) for recurrent isolated<unk> . Diagnosis Episodes of<unk>  can occur in the context of several medical conditions (e.g., narcolepsy, hypokalemia). When episodes occur independent of these conditions or substance use, it is termed "isolated<unk> " (ISP). When ISP episodes are more frequent and cause clinically significant distress or interference, it is classified as "recurrent isolated<unk> " (RISP). Episodes of<unk> , regardless of classification, are generally short (1–6 minutes), but longer episodes have been documented. It can be difficult to differentiate between cataplexy brought on by narcolepsy and true<unk> , because the two phenomena are physically indistinguishable. The best way to differentiate between the two is to note when the attacks occur most often. Narcolepsy attacks are more common when the individual is falling asleep; ISP and RISP attacks are more common upon awakening. Differential diagnosis Similar conditions include: *Exploding head syndrome (EHS) potentially frightening parasomnia, the hallucinations are usually briefer always loud or jarring and there is no<unk>  during EHS. *Nightmare disorder (ND); also REM-based parasomnia *Sleep terrors (STs) potentially frightening parasomnia but are not REM based and there is a lack of awareness to surroundings, characteristic screams during STs. *Noctural panic attacks (NPAs) involves fear and acute distress but lacks<unk>  and dream imagery *Posttraumatic stress disorder (PTSD) often includes scary imagery and anxiety but not limited to sleep-wake transitions
Sleep paralysis
Narcolepsy
Sedation
Night terror
Sleep disorder
Hypokalemic periodic paralysis
Syncope 
Atonic seizure