Patient presents with leukocytosis, defined as an elevated white blood cell count (WBC).  Differential diagnosis includes infection, inflammation, bone marrow disorders such as leukemia or lymphoma, stress, and certain medications.  Presenting symptoms may include fever, fatigue, body aches, and localized signs of infection such as redness, swelling, or pain.  Physical examination findings may be consistent with the underlying cause of the leukocytosis.  Complete blood count (CBC) with differential reveals an elevated WBC exceeding the normal range.  Further laboratory investigations, such as peripheral blood smear, bone marrow biopsy, or imaging studies like CT scan or ultrasound, may be indicated depending on the clinical picture.  Treatment for leukocytosis is directed at the underlying cause.  For example, if infection is identified, appropriate antibiotic therapy will be initiated.  If a malignancy is suspected, referral to hematology-oncology for further evaluation and management is warranted.  Patient education regarding symptoms to monitor and when to seek medical attention is crucial.  Follow-up CBC with differential will be scheduled to monitor the white blood cell count and response to treatment.  ICD-10 code R70.0, Leukocytosis, is used for billing and coding purposes.  CPT codes for associated laboratory and imaging studies will be appended as appropriate.  This documentation supports medical necessity for the diagnostic workup and treatment plan for leukocytosis.