Abnormal lymphocyte count can have various causes, ranging in severity from 'minor' to 'generally fatal'. Finding the true cause means ruling out or confirming each possibility – in other words, diagnosis.
Diagnosis is usually a complex process due to the sheer number of possible causes and related symptoms. In order to diagnose abnormal lymphocyte count, we could:
|Bone Marrow Suppression||17%||Unlikely|
|Aplastic Anemia||1%||Ruled out|
|Multiple Myeloma||1%||Ruled out|
|Whooping Cough||0%||Ruled out|
|Myasthenia Gravis||0%||Ruled out|
White Blood Cells - Lymphocyte Percentage [fraction]
Possible responses:→ Don't know
→ Under 20% [0.20] (low)
→ 20 to 45% [0.20-0.45] (normal)
→ 46 to 55% [0.46-0.55] (elevated)
→ Over 55% [0.55] (high)
Certain drugs, such as mephenytoin, dilantin and para-aminosalicylic acid, can cause an increased lymphocyte count.
Autoimmune problems such as rheumatoid arthritis can cause reduced lymphocyte counts.
A complete blood count may show large numbers of lymphocytes in a pertussis patient.