The most common cause of lethargy in infants younger than 2 to 3 months of age is sepsis. Although there are other causes to consider (eg, methemoglobinemia), all infants in this age group with lethargy should be considered septic until proven otherwise.
Check our archive to test your knowledge in other pediatric cases:
If you do not already have Acrobat Reader, simply click on the icon below, scroll down to the "Get the Free Acrobat Reader" heading and follow the instructions to install the program. Acrobat enables you to convert any document into an Adobe Portable Document Format (PDF) file for easy viewing.