Diagnose It Answer — April 23, 2026

38-year-old female presents with a 4-day history of left calf pain, swelling, and warmth. She initially thought she had pulled a muscle but the leg has continued to swell and now feels 'hot and heavy.' She is 6 weeks postpartum following a cesarean section. She reports mild shortness of breath that started today, which she attributes to anxiety.

Uncomplicated C-section 6 weeks ago with a hospital stay of 4 days. She has been mostly sedentary since discharge, caring for her newborn at home. She is breastfeeding and takes prenatal vitamins. No prior history of blood clots. Mother had a DVT after a long flight 10 years ago. She has been on oral contraceptive pills in the past. Does not smoke. No recent travel.

BP 124/76 mmHg, HR 94 bpm, RR 18 breaths/min, Temp 37.2°C, SpO2 97% on room air. Left lower extremity: visibly swollen compared to right — circumference 4cm larger at mid-calf. Left calf is erythematous, warm to touch, and tender to palpation along the medial aspect. Dorsiflexion of the left foot elicits sharp calf pain (Homan's sign positive — poor specificity but noted).

Wells DVT score: 4 (high probability) — recent immobilization after surgery, entire leg swollen, calf swollen >3cm compared to other leg. Pulmonary embolism Wells score also calculated given new dyspnea: 4.5 (PE likely). CT pulmonary angiography ordered to rule out concurrent PE. Compression duplex ultrasound of left lower extremity ordered — performed at bedside. Anticoagulation initiated after imaging: enoxaparin 1mg/kg SC BID given patient is breastfeeding (LMWH does not cross into breast milk significantly).

D-dimer: 3,840 ng/mL (markedly elevated; normal <500 ng/mL — always elevated postpartum, limiting its utility in this setting). CBC: WBC 9,200/µL, Hgb 11.4 g/dL (postpartum anemia). Duplex ultrasound left lower extremity: non-compressible left popliteal and femoral veins with intraluminal echogenic thrombus — proximal DVT confirmed. CTPA: no pulmonary embolism identified. Hematology and OB consulted regarding duration of anticoagulation and thrombophilia workup.