Common Symptoms Include: Leg pain or tenderness Leg swelling Discoloration of leg; usually blue, purple, or red Regardless of the cause, Deep Vein Thrombosis (DVT) can be particularly dangerous if left untreated. [venousinstitute.com]

Since the leg pain associated with DVT is very similar to muscle pain, your doctor might look for signs of swelling and enlargement of the calf due to swollen leg veins. A diagnosis of DVT is usually confirmed with a compression ultrasound. [medbroadcast.com]