Sudden breathlessness brain numbness can be seen in tachycardia, cardiac neurosis, bronchial asthma and so on. 1. Tachyarrhythmia: some patients may have sudden onset of tachycardia, such as paroxysmal supraventricular tachycardia, which may be characterized by severe chest tightness and breathlessness, accompanied by numbness in the brain. 2. Cardiac neurosis: patients may be mentally overstressed, which may manifest as sudden chest tightness, breathlessness, which may be accompanied by hyperventilation, leading to temporary respiratory alkalosis, which manifests as brain numbness. 3. Bronchial asthma: the patient may suddenly come into contact with allergens, resulting in an acute asthma attack, manifested as a lack of breath brain numbness. Suddenly appeared out of breath with brain numbness may also be caused by other reasons, to remain calm, it is recommended to timely accompanied by family members or coworkers to the hospital, by the doctor to check and receive treatment.