Haemoglobin and blood indices, serum levels of calcium, inorganic phosphorus, alkaline phosphatase, urea, glucose, sodium, potassium and chloride. The urine was tested for glucose and protein.In all patients with marked finger clubbing radiographs were taken of the extremities to detect the presence of hypertrophic osteoarthropathy. Other investigations, such as estimations of serum thyroxine levels, were performed when indicated clinically or as a result of the initial investigations.The following diagnostic criteria were observed: finger clubbing was recorded only when three independent observers agreed to its presence and hypertrophic osteoarthropathy when a patient with finger clubbing showed radiographic evidence of periostitis; significant weight loss, when it exceeded 6-4 kg (one stone); anaemia when the haemoglobin level was less than 10-0 g/100 ml (anaemia was considered normocytic when the mean corpuscular volume exceeded 75 ,ug and microcytic when it did not); hypercalcaemia when the serum calcium exceeded 11-5 g/100 ml on two or more occasions; hyponatraemia due to inappropriate antidiuretic hormone (ADH) secretion when the serum sodium was less than 125 mEq/l and the urine was hyperosmolar to the plasma; fever with an oral temperature in excess of 375°C on three or more occasions during admission (excluding postoperative pyrexia); hyperthyroidism when the serum thyroxine TABLE I