The Full Form of GRBS is General Random Blood Sugar.

The blood sugar level, blood sugar concentration, or blood glucose level is the measure of concentration of glucose present in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the blood of a 70 kg (154 lb) human at all times. The body tightly regulates blood glucose levels as a part of metabolic homeostasis. Glucose is stored in skeletal muscle and liver cells in the form of glycogen; in fasting individuals, blood glucose is maintained at a constant level at the expense of glycogen stores in the liver and skeletal muscle.

Random glucose test (a.k.a. random blood glucose) is a blood sugar test taken from a non-fasting subject.

This test, also called capillary blood glucose (CBG), assumes a recent meal and therefore has higher reference values than the fasting glucose test.