The recovery time for viral influenza, or flu, depends on the severity of the illness and the ability of the autoimmune system. The main manifestations of influenza are acute onset of high fever, generalized pain, significant malaise and mild respiratory symptoms. Since influenza is self-limiting, the temperature usually drops to normal in about 3-5 days, and most of the symptoms such as cough and malaise can disappear in about 1-2 weeks. For elderly people over 65 years old, children under 5 years old, pregnant women or people with other chronic diseases, the course of the disease is usually relatively long due to low autoimmune function, and some patients may develop into severe influenza due to lack of timely treatment, causing complications such as pneumonia, sepsis, and shock, which can even affect life. During the treatment period, influenza patients should pay attention to adequate rest, reasonable and comprehensive diet and nutrition, and pay attention to protection against cold and warmth and indoor ventilation.