The most common sign of deep vein thrombosis is swelling of the leg which usually happens in the entire leg so if you notice your leg suddenly swelling then it's likely you have deep vein thrombosis and should see a doctor or get to the emergency room or urgent care as soon as possible.
Other warning signs of deep vein thrombosis are Chest pain or discomfort that worsens when you take a deep breath or when you cough, Coughing up blood, Rapid Pulse, Shortness of breath that happens Suddenly and fainting or feeling lightheaded or dizzy.
Deep Vain Thrombosis is a very serious condition and can be fatal if not treated so always seek medical attention if you think you're having or about to experience Deep Vein Thrombosis.