Acute Deep Venous Thrombosis (DVT) half of the times causes no symptoms. Sometimes, as pieces of clot break off, the first manifestation may be pulmonary embolism. The classic symptoms of DVT, when present, include:
• Swelling of the leg (sometimes both) or arm
• Leg pain or tenderness that may only be present when standing or walking
• Increased warmth in the swollen or painful area of the leg or arm
• Redness or discoloration of the skin
• Enlargement of the superficial veins in the affected leg or arm
Symptoms of a pulmonary embolism include:
• Sudden shortness of breath
• Sharp chest pain, often aggravated by coughing or movement
• Pain in the back
• Cough with or without bloody sputum
• Excessive sweating
• Rapid pulse or breathing
• Lightheadedness or passing out
The symptoms of acute pulmonary embolism or acute deep vein thrombosis may resemble other medical conditions or problems. Do not wait to see if the symptoms will "go away". It is important to notify your doctor immediately or go to the emergency room if you experience these symptoms. Seek treatment right away to prevent serious complications.
As the blood clot ages (after 1 month) it becomes harder and may turn to a scar (chronic DVT). As a result of this process, the vein becomes much smaller and does not allow blood to flow through effectively; other times the vein lumen gets open (recanalizes), however valve damage results in deep venous insufficiency and venous reflux (blood flow is directed "downwards" instead of "upwards"). As the blood pools, it can cause chronic swelling, pain, increased pigmentation or discoloration of the skin and leg ulcers known as venous stasis ulcers. This condition is called post-thrombotic syndrome and typically will manifest several years after the initial DVT. The severity of the symptoms depends on the extent and location of the DVT.
Regarding superficial thrombophlebitis, as it occurs close to the skin surface, it usually causes pain, swelling and redness in the area of the vein. The only risk of superficial thrombophlebitis is that it may progress into the deep veins, and as it turns to a DVT it may lead to the symptomatology and risks that were described earlier. However, superficial thrombophlebitis in the majority of cases has a benign course.