<unk>  is believed to be caused by psychological factors and by definition has no organic cause. It is one cause of<unk>  with others including infection, blood loss, heart attack, hypocapnia or alkalosis due to chemical imbalances, decreased cerebral blood flow, and increased nerve sensitivity. In one study, one third of patients with<unk>  had "subtle but definite lung disease" that prompted them to breathe too frequently or too deeply. A study, found that 77% of patients with empty nose<unk>  have<unk> . Empty nose<unk>  can appear in people having done nose surgery like cauterization, turbinectomy, turbinoplasty, etc. Many people with panic disorder or agoraphobia will experience<unk> . However, most people with<unk>  do not have these disorders.
Hyperventilation syndrome
Central hypoventilation syndrome
Obesity hypoventilation syndrome
Upper airway resistance syndrome
Sleep apnea
Reactive airway disease
Central sleep apnea
Asthma