| Insufficient sleep |
| Sleep deprivation |
| Environmental intrusions |
| Sleep disorders |
| Obstructive sleep apnea |
| Central sleep apnea |
| Sleep-related hypoventilation or hypoxemia |
| Central disorders of hypersomnolence |
| Narcolepsy type 1 or 2 |
| Kleine-Levin syndrome |
| Idiopathic hypersomnia |
| Circadian rhythm sleep-wake disorders |
| Delayed sleep-wake phase disorder |
| Advanced sleep-wake phase disorder |
| Irregular sleep-wake rhythm disorder |
| Non-24-hour sleep-wake rhythm disorder |
| Jet lag |
| Shift work |
| Restless legs syndrome |
| Periodic limb movement disorder |
| Other neurologic disorders |
| Neurodegenerative disease |
| Parkinson disease |
| Dementia with Lewy bodies |
| Alzheimer disease |
| Multiple system atrophy |
| Myotonic dystrophy |
| Multiple sclerosis |
| Amyotrophic lateral sclerosis (via sleep-related breathing disorders) |
| Structural lesions affecting thalamus, hypothalamus, or brainstem |
| Traumatic brain injury |
| Encephalitis lethargica |
| Cerebral trypanosomiasis |
| Medical and genetic disorders |
| Hypothyroidism |
| Obesity |
| End-stage renal disease |
| Adrenal insufficiency |
| Hepatic encephalopathy |
| Niemann-Pick type C |
| Prader-Willi syndrome |
| Psychiatric disorders |
| Depression |
| Anxiety |
| Substance abuse |
| Alcohol |
| Narcotics |
| Prescription opioid abuse |
| Stimulant withdrawal |
| Psychogenic sleepiness |
| Medications |
| Benzodiazepines |
| Nonbenzodiazepine sedatives |
| Antipsychotics |
| Opioid analgesics |
| Beta-blockers (lipophilic) |
| Barbiturates |
| Antihistamines |
| Antiseizure medications |
| Sedative antidepressants |
