what are the symptoms of blood clots?

When a thrombus occupies more than 75% of surface area of the lumen of an artery, blood flow to the tissue supplied is reduced enough to cause symptoms because of decreased oxygen (hypoxia) and accumulation of metabolic products like lactic acid. More than 90% obstruction can result in anoxia, the complete deprivation of oxygen, and infarction, a mode of cell death.
Cerebral thrombosis (blood clot in the main cerebral artery of the brain) may cause stroke.
Coronary thrombosis (blood clot in the coronary artery) may cause heart attack.
Deep vein thrombosis may cause pulmonary embolism.
Symptoms will differ according to the location of the blood clot in the various organs of the body.

What are the symptoms of blood clots?

Venous clots do not allow blood to return to the heart and symptoms occur because of this damming effect. Most often occurring in the legs or the arms, symptoms include:

•swelling,

•warmth,

•redness, and

•pain.
Arterial clots do not allow blood get to the affected area.

•Pain is the initial symptom of this ischemia, or oxygen deprivation due to loss of blood supply.

•Other symptoms depend upon the location of the clot, and often the effect will be a loss of function. Heart attack and stroke are self-explanatory.

•In an arm or leg, in addition to pain, the limb may appear white, and weakness, loss of sensation, or paralysis may occur.

•If the blood supply is lost to an area of the bowel, in addition to intense pain, there may be bloody diarrhea.

Dr. Harvey D. Cohen is board certified in both internal medicine and geriatric medicine. He has been in private practice in Rancho Cucamonga since 1979.

For this week’s Focus on 5, Cohen answers questions on deep vein thrombosis.

Blood clots can result from many factors

Q. what is a deep vein thrombosis (DVT)?

A. Deep Vein Thrombosis is a clot formed in the venous system. it mainly affects large veins in the lower legs and thighs; however, it may affect other veins as well. The clot can block blood flow. if the clot breaks off and moves through the blood stream, it can get stuck in the lung, the brain or the heart. if the clot ends up in the lung, it is called a pulmonary embolism. if it ends up in the brain, the result is either a cerebral vascular accident “CVA” or transient ischemic attack “TIA.” if it affects the heart, it can block the outflow of blood to the lung.

Q. what causes deep vein thrombosis?

A. Bed rest, cigarette smoking, fractures, medications such as estrogen and birth control pills, recent surgery, especially in the hip, knee and female reproductive system, obesity, and sitting for long periods of time such as on long plane or car trips. there are also congenital abnormalities of blood clotting such as factor V mutation, anti-thrombin 3 deficiency, and pro-thrombin mutation. these can increase the risk of getting a deep vein thrombosis. Deep vein thrombosis also may appear as the first sign of cancer, particularly colon cancer or pancreatic cancer. Finally, there are illnesses that may thicken the blood and lead to DVT.

Q. I hurt my calf when I fell off my bicycle two days ago and now my calf is swelling and painful. do you think I have a deep vein thrombosis?

A. maybe. you may have swelling just because of the damage to the effected tissues; however, I agree with your thoughts that swelling and tenderness in one leg with increased warmth and/or changes in skin color, such as redness, may be the signs of deep vein thrombosis.

This should be quickly evaluated by your physician. An ultrasound doppler of the lower extremity should be performed. if the clot is above the popliteal area (behind the knee) then treatment with anti-coagulation (blood thinners) should be started. if, however, the clot is below the popliteal area, you should repeat the ultrasound in three to five days to evaluate for progression of the clot into or beyond the popliteal area. if the blood clot stays beneath the popliteal area there is usually no reason for starting anti-coagulation.

Q. three days ago I returned from Australia and I became short of breath and felt a rapid heart beat. I went to the emergency department and I was told I had a pulmonary embolism. what does all of this mean?

A. Long airplane or car trips without walking may cause a stagnation of blood in your lower extremities. A blood clot can form without showing any symptoms such as swelling, pain, or redness in the legs. after the trip, when you got up and out of the plane and walked around, part of this clot broke off and went upstream into your heart, then into the pulmonary artery and finally into your lung. The size of the clot and the underlying condition of your lungs will determine the symptoms you will have. Difficulty breathing, chest pain, especially when you inhale, and heart pounding may be your only symptoms; however, if the blood clot is very large or you have severe underlying lung disease, this could lead to sudden death. To diagnose pulmonary embolism, we utilize a CT pulmonary angiogram or, in some cases, if the patient has kidney disease, a ventilation perfusion scan. Infrequently, we also may utilize pulmonary angiogram where a catheter is placed into your pulmonary artery and a contrast material is injected. if there is a very severe pulmonary embolism causing a significant drop in blood pressure and an inability to get adequate oxygen in your blood, then thrombolysis with medications such as TPA (tissue plasminogen activator) may be utilized to break down the clot. in some cases, surgical intervention to remove the clot is necessary.

Q. I have a blood clot in my lower extremity from below the knee into my groin; however, two months ago I had a bleeding gastric ulcer. I am afraid to take a blood thinner since my stomach ulcer might start to bleed again.

A. you are right on target. it would be contra-indicated to give you an anti-coagulant for at least six months, if not more, after having a gastric ulcer bleed. in order to prevent a blood clot going from your leg into your lung, your physician will advise you to have an inferior vena cava (IVC) filter. This device is placed into your inferior vena cava via a catheter. The vena cava is one of the largest veins in your body. A large blood clot would not be able to go to the lung since it would be stopped by this filter. at times the IVC filter may only be a temporary device that could be removed in the near future. you should speak to your physician regarding these options.