Emotional or psychiatric causes
Pain, anger, or anxiety
Response to fever (about 10 bpm per degree C > 37.0)
SIRS (from infection or other causes)<unk> /hypovolemia
Anemia
Drug/alcohol intoxication (particularly sympathomimetic or anticholinergic drugs, but may also be seen in aspirin, theophylline, or other ingestions)
Drug/alcohol withdrawal
Anion gap acidosis
Hyperthyroidism
PE
CHF
Cardiac tamponade
Myocardial contusion
Cardiac valvular disease
Hyper or hypoglycemia
Myocardial infarction
Pheochromocytoma
Pain, anger, or anxiety
Dehydration
Emotional or psychiatric causes
Diabetic ketoacidosis 
Pain, anger, or anxiety
Diabetic ketoacidosis
Response to fever 
Syndrome of inappropriate antidiuretic hormone secretion
SIRS 