Hyperventilation The blood contains carbon dioxide, which is a waste product of cellular metabolism.  It is also a part of the blood's acid-base balance system. Carbon dioxide is blown off from the lungs, with an optimum partial pressure of 40 mm Hg, and a blood pH of 7.40. In Hyperventilation, if too much carbon dioxide is blown off, the pH in the blood rises and becomes alkalotic. Tingling in the hands and feet on both sides of the body Rapid breathing Anxiety Muscle Spasm Anxiety Hypoxemia (decrease oxygen in blood) Lung diseases Severe infections (sepsis) Liver failure Pain Fever Brain stem injury Usually made from history.  If the cause is anything other than Anxiety, a medical work-up should be pursued. Heart and lung exam will be performed. Arterial blood gas will confirm the diagnosis EKG and chest X-Ray will probably be performed to rule out other causes. Anxiety as cause -- breathing into paper bag (until symptoms improve). Anti-Anxiety medications can be helpful Seek immediate medical advice, as serious medical conditions may mimic Hyperventilation.  For example, a Pneumothorax (Collapsed Lung) or Pulmonary Embolism may have identical symptoms to Hyperventilation.  And, of course, it will cause Anxiety -- not enough oxygen is getting into the blood! Myocardial Infarction Angina pectoris Pulmonary Embolism Hypertrophic Cardiomyopathy Spontaneous Pneumothorax