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.
Stress is an important causing factor.Other causes being anxiety,hypoglycemia,vit B12 deficiency and hyperthyroidism.