This is a difficult question to answer. Any type of infection can caue the above symptoms. Anything from mononucleosis, malaria, lymphoma, strep, etc. the list is virtually endless. A GOOD history and physical exam by an experienced doctor will help him start to figure out which tests to order. It can be a lenghty process, since it is a process of elimination.
In blood
cat is to kitten as dog is to
atypical lymphocyte
lymphocyte
Lymphocyte
lymphocyte
lymphocyte
Lymphocyte...
lymphocyte
Absolute lymphocyte count is the number of lymphocytes (a certain type of infection fighting white blood cell) in a given volume of blood. This is in distinction to the percentage of white cells that are lymphocytes.
T - lymphocyte
lymphocytes