Blood sugar is the amount of glucose in the blood. The consumption of food defined as food is vital for humans. Food is defined in Article 2 of Regulation (EC) No 178/2002 as "a substance or product intended to be, or reasonably expected to be ingested. Several pathologies can impose on patients the inability to eat orally. This inability to eat orally poses a problem in the management, particularly in developing countries, because food, according to Hippocrates, is the first medicine. The objectives of our study were: To describe the clinical, and socio-demographic aspects of patients unable to eat; To determine the frequency of hyperglycemia and hypoglycemia in patients unable to eat in the department; To identify the probable factors of hyperglycemia and hypoglycemia in patients unable to eat in the department of infectious diseases; To compare the blood glucose levels before and after intake of glucose solutions in these patients