Patient presents with complaints consistent with left leg deep vein thrombosis (DVT).  Symptoms include left lower extremity pain, swelling, and tenderness to palpation along the calf.  Onset of symptoms occurred approximately three days ago and has progressively worsened.  Patient denies any chest pain, shortness of breath, or hemoptysis.  Risk factors for DVT were assessed, including recent prolonged immobility due to a long car trip, family history of thromboembolic events, and oral contraceptive use.  Physical examination reveals edema and erythema of the left leg, with increased warmth compared to the right leg.  Homan's sign is negative.  D-dimer level is elevated.  Compression ultrasonography of the left lower extremity confirms the presence of a thrombus in the left popliteal vein.  Diagnosis of acute left leg deep vein thrombosis is made.  Treatment plan includes initiation of anticoagulant therapy with rivaroxaban, patient education regarding medication administration, signs and symptoms of pulmonary embolism, and importance of follow-up care.  Patient advised to avoid prolonged immobility and elevate the affected leg.  Referral to hematology for further management and evaluation for underlying thrombophilia will be considered.  ICD-10 code I80.222, Left leg deep venous thrombosis, is documented.  Follow-up appointment scheduled in one week to monitor treatment response and assess for potential complications such as bleeding or recurrent thrombosis.