The normal range of routine blood tests for lymphocyte values is between 20% and 40%. If there is an increase in lymphocytes, the possibility of viral infection is considered more likely. Patients most commonly have upper respiratory tract infections with significant fever, runny nose, cough or sputum, as well as peripheral muscle aches and pains, which usually require antiviral therapy, and should be advised to drink plenty of fluids. If there is a decrease in lymphocytes combined with an increase in the proportion of neutrophils, it is a sign of an inflammatory response in the body. There should be primary foci of infection and also fever, which should be treated systematically with anti-infective therapy. There are also cases of immunocompromised patients with viral infections, but the lymphocytes may not have a significant response, which should be determined by the clinical picture.