It sounds as if you may be having a panic attack. http://en.wikipedia.org/wiki/Panic_attack From the link: ----- Sufferers of panic attacks often report a fear or sense of dying, going crazy , or experiencing a heart attack or flashing vision , feeling faint or nauseated, heavy breathing, or losing control of themselves. These feelings may provoke a strong urge to escape or flee the place where the attack began (a consequence of the sympathetic fight or flight response). A panic attack is a response of the sympathetic nervous system (SNS). The most common symptoms may include trembling, dyspnea (shortness of breath), heart palpitations, chest pain (or chest tightness), hot flashes, cold flashes, burning sensations (particularly in the facial or neck area), sweating, nausea, dizziness (or slight vertigo), light-headedness, hyperventilation, paresthesias (tingling sensations), sensations of choking or smothering, and derealization.