###Human: What are the symptoms of DVT? ###Assistant: Hello. Leg pain behind the knees which is localized, non radiating in nature with no swelling, no history of prolonged bed rest and no fracture of a limb. Hence, this is not deep vein thromboembolism. DVT occurs when there is a prolonged history of immobilization with sudden onset of swelling. This also does not look like cellulitis where is a superficial subcutaneous infection, which is most common cause of swelling and pain. If this is more on walking, then we have to rule out claudication first and second is knee joint pathology. Kindly tell me if there is any history of trauma or fall, or any associated disease.