Enhanced physiologic<unk>  (e.g. anxiety)
Essential<unk>  (familital)
Parkinson's disease
Hyperthyroidism
Hepatic encephalopathy
Cerebellar dysfunction
Wilson's disease
Hypoglycemia
Toxicology:
Caffeine, theophylline
Sympathomimetics
ETOH withdrawal
Antipsychotics
Metoclopramide
Lithium
Levothyroxine<unk> icyclic antidepressants
Valproic acid
Hydrogen Sulfide
Serotonin syndrome
Salicylate toxicity
Bupropion
Heavy metal toxicity
West Nile virus
Caffeine, theophylline
Sympathomimetics
ETOH withdrawal
Antipsychotics
Metoclopramide
Lithium
Levothyroxine<unk> icyclic antidepressants
Valproic acid
Hydrogen Sulfide
Serotonin syndrome
Salicylate toxicity
Bupropion
Heavy metal toxicity
Tremor
Enhanced physiologic tremor 
Catatonia
Essential tremor 
Sedation 
Parkinson's disease
Chorea
Hyperthyroidism