A nurse is giving a presentation about preventing deep-vein thrombosis (DVT). Which of the following should the nurse include as a risk factor for this disorder? (Select all that apply.)

Rationale: A. Oral contraceptive use: Estrogen in oral contraceptives increases coagulability of the blood, raising the risk of venous thrombosis. Women who use oral contraceptives are at higher risk of developing DVT, especially if combined with smoking or immobility. B. Hypertension: While hypertension contributes to arterial diseases such as stroke or myocardial infarction, it is not considered a primary risk factor for venous thrombosis. DVT is more closely associated with venous stasis, endothelial injury, and hypercoagulability. C. BMI of 20: A body mass index of 20 falls within the normal weight range and does not increase the likelihood of developing DVT. Obesity, rather than a healthy BMI, is the condition that contributes significantly to venous stasis and thrombus formation. D. High calcium intake: Increased calcium intake does not contribute to venous clot formation or elevate DVT risk. DVT risk is more related to factors such as immobility, hypercoagulability, surgery, and trauma, not dietary calcium levels. E. Immobility: Limited mobility slows venous return from the lower extremities, leading to venous stasis. This stagnation of blood flow is a key factor in clot formation, making immobility one of the strongest and most common risk factors for DVT.