This chapter deals with renal, metabolic and endocrine emergencies, and covers acute renal failure (ARF), rhabdomyolysis, hyperkalaemia, diabetic ketoacidosis (DKA), hyperosmolar hyperglycaemic nonketotic states (HONKS), hypokalaemia, hypoglycaemia, hyponatraemia, Addison’s disease, hypocalcaemia, hypercalcaemia, thyrotoxic crisis, acid-base balance. ARF is an abrupt decline in renal function diagnosed by rapidly rising blood urea and creatinine. Rhabdomyolysis has muscle signs in 50 per cent, myoglobin is absent in urine in 30% and should be considered in trauma, burns, epilepsy, coma with hypotension, falls and self poisoning. Hyperkalaemia always occurs in the context of acute or chronic renal failure. Mild hypoglycaemia is common in patients on insulin and usually managed by them. Severe hypoglycaemia requires help from another person. Mild hypoglycaemia is common in patients on insulin and usually managed by them. Severe hypoglycaemia requires help from another person. Symptoms, causes and management of all the discussed emergencies are also presented in this chapter.