The main symptoms in patients are swelling and pain in the lower limbs and pressure pain in the back of the calf and/or inner thighs, which worsens with activity and improves with elevation of the affected limb. The skin may appear normal or mildly bruised in mild cases, or may be bruised in severe cases. Once dislodged, the venous thrombus can drift with the blood flow and can block the main trunk or branches of the pulmonary artery causing pulmonary embolism and symptoms such as shortness of breath, chest pain or coughing up blood.