INS and thyrotoxic periodic paralysis: The severity of muscle weakness depends on the degree of hypokalaemia.6 Hypokalemia is the result of intracellular shift of potassium due to increased activity of Na+/K+-ATPase pump under the influence of increased thyroid hormones.1-5 The activity of Na+/K+-ATPase pump is enhanced by other factors such as insulin, adrenergic stimulation, androgens or exercise, hence, these factors may predispose to an attack in TTP patients.3 Patients with thyrotoxic periodic paralysis have higher Na+/K+-ATPase pump activity compared to those without paralytic attacks.4