Glucose is an important nutrient for human body, which is absorbed quickly after oral administration. After ingestion, various carbohydrates are also decomposed or converted into glucose for tissue utilization, or converted into glycogen or fat for storage. The human body generally uses 800 mg of glucose per kilogram of body weight per hour, so it is an important energy source in total parenteral nutrition therapy. Normal people's plasma glucose concentration is often maintained in a certain range, mainly relying on neuroendocrine regulation. When blood sugar is lowered, it can accelerate fat catabolism and increase ketone body production, which can lead to ketosis. Insulin can antagonize the above-mentioned effects of nerve and endocrine hormones and lower blood sugar. The energy supply required by brain tissue mainly depends on glucose. If the blood sugar level is low, the energy supply of nerve tissue is insufficient, or various nervous system manifestations, such as palpitation (sympathetic nerve reaction), hand trembling, convulsion, coma and so on, are caused. When glucose and insulin are injected together, potassium ions can be brought into cells, which can reduce the blood potassium concentration in a short time. When the effect of insulin is eliminated, potassium ions are released again. Oral or intravenous injection of glucose injection to observe the changes of blood glucose concentration and plasma insulin concentration (glucose tolerance test) is helpful to diagnose diabetes, spontaneous hypoglycemia and pituitary hypofunction. Hypertonic glucose can dehydrate tissues, but its effect is short-lived, and it is only used to treat dialysis imbalance. Adding different concentrations of glucose to peritoneal dialysis solution can adjust osmotic pressure and eliminate water. Injecting 5% glucose injection into dehydrated patients can replenish lost water and relieve hypertonic dehydration.

Generally, there is enough glucose intake in the normal diet, so it is meaningless to give glucose to patients or healthy people who are not short of glucose. It is incorrect to regard glucose as a nutritional tonic and think that the more kinds of tonics, the better, and the greater the dosage.