A personal medical history considering any medical conditions, any medications being taken, and any stressful life events/changes that could be causing<unk> 
Screen for mood disorders, PTSD, substance use disorders
A sleep history and review of sleep and wake diaries can be helpful in determining the cause
Insomnia
Alcohol Abuse, alcohol, benzo, or opioid withdrawal
Ergotism
Depression/anxiety
Sedation 
Bipolar disorder, schizophrenia
Hiccups
Hepatic encephalopathy