Initial tests usually include some combination of a complete blood count (CBC), electrolytes (including calcium and magnesium), glucose, kidney and liver function tests, thyroid-stimulating hormone (TSH), erythrocyte sedimentation rate (ESR), and hepatitis C serologic testing. If sudden or severe true general weakness or any respiratory symptoms are present, forced vital capacity and maximal inspiratory force must be tested to assess risk of acute ventilatory failure.