Even if crying is part of an infant's normal development during the first three months of life, it is important to differentiate normal crying of infancy from crying caused by an illness (e.g. infection, cow's milk allergy, acute surgical diseases). Differential diagnostics are based on history and clinical examination. An excessively crying baby may induce feelings of disappointment and helplessness in the parents and is always a burdensome problem for the family. The treating physician should show empathy and never underrate the effect of the crying on the family even if no underlying illness is diagnosed.