Tetany is a disorder with a very heterogeneous clinical manifestation. It includes neuromuscular hyperactivity, decreased attention, fatigue, constant anxiety. Attacks of tetany range from mild symptoms, which includes circumoral and distal paresthesias, hyperventilation, accompanied by shortness of breath, palpitation, dizziness, nausea and carpopedal spasm, through more severe symptoms like generalized seizures, loss of consciousness, muscle crumps to life-threatening emergencies like laryngospasm or arrhythmias. Tetany can be a result of many electrolyte disturbances, like hypocalcaemia, hypomagnesemia, hypokalaemia, alkalosis and electrolyte disturbances following hyperventilation. These disorders may occur in many clinical situations including diet deficiencies, alcoholism, endocrine diseases, genetic disorders, iatrogenic causes like proton pump inhibitors therapy and many, many others. It happens that tetany is diagnosed too late and therefore insufficiently cured. For these reason it deserves closer attention.