Causes of Deep Vein Thrombosis

Deep venous thrombosis is more common in adults over 60 years of age. However, it can occur at any age.

When a clot breaks down and travels through the bloodstream it is called an embolism .

The embolism can get stuck in the brain, lungs, heart or other areas, causing serious damage.
Blood clots can form when something slows or changes the blood flow in the veins, usually occurs in the lower limbs, rarely occurs in the upper limb or the arm (about 3% of cases).

The risk factors are:

  • A central venous catheter that passes through the groin vein irritates the vessel wall and reduces blood flow.
  • Prolonged rest, such as during a long hospital stay, or in case of paralysis.
    When the legs remain standing for long periods, they do not contract the calf muscles that help the blood circulation, so they develop blood clots.
  • An earlier episode of deep vein thrombosis or pulmonary embolism. If there has been deep vein thrombosis in the past, you are more likely to have a relapse.
  • A family history of deep venous thrombosis or pulmonary embolism. If anyone in the family has suffered from these problems, the risk of developing deep venous thrombosis increases.
  • Fractures of the pelvis , femur , tibia and fibula .
  • A birth in the last 6 months.
  • Obesity.
  • Recent surgery (more common in the hip, knee or an operation on the female pelvis).
  • Pregnant women. The pregnancyincreases pressure in the veins of the pelvis and legs. Females with a hereditary coagulation disorder are particularly at risk. The possibility of developing a blood clot during pregnancy can continue for up to six weeks after giving birth.
  • Many blood cells produced in the bone marrow can have an effect on the blood that becomes denser and flows more slowly than normal.
  • Age, it is the elderly who are likely to be at much more risk, but deep venous thrombosis can also affect young people.

The formation of a blood clot is most likely in the veins of people with certain problems or diseases, such as:

  • Cancer . Some types of neoplasia increase the amount of substances in the blood that produce the blood clot.
    Any cancer treatments increases the risk of blood clots.
  • Inflammatory bowel disease . Some intestinal diseases such as ulcerative colitis increase the risk of deep venous thrombosis.
  • Heart failure . Those who suffer from heart failure have an increased risk of deep vein thrombosis because a damaged heart does not pump blood like a normal heart.
    This increases the possibility of congestion and a blood clot.
  • Birth control pills or hormone replacement therapy. Both birth control pills(oral contraceptives) that hormone replacement therapy may increase the risk of deep vein thrombosis.

When you sit for long periods when traveling, you may increase the risk of deep vein thrombosis. This is most likely if you have one or more of the risk factors listed above.
According to the guidelines of the American College of Chest Physicians (ACCP) you do not need to take an anticoagulant before boarding, but you may want to sit on the aisle seat to walk during the trip.


Symptoms of Deep Vein Thrombosis

Patients with deep venous thrombosis may have a variable staining of the lower limb.
The most common abnormal color  is purple / reddish  congestion and venous obstruction . In rare cases, the leg is cyanotic with severe femoral vein obstruction.
This ischemic vein occlusion form was originally described as “flegmasia cerulea dolens” (” blue painful inflammation “). The leg is usually very swollen, painful and cyanotic. There are often bruises .

In some cases, deep venous thrombosis does not cause symptoms in other cases may occur:

  • Swelling and numbness in one leg (usually in the belly of the leg or calf)
  • Acute and constant pain in the affected area
  • Hot skin at clot level
  • Redness of the skin, especially on the back of the leg below the knee
  • Fever , but not always.

Deep venous thrombosis usually (although not always) affects only one leg. The pain may worsen by bending the foot up toward the knee.

If deep venous thrombosis is not treated, it can cause a pulmonary embolism, a blood clot that travels from the point where it was formed and develops in one of the lungs.
In the case of pulmonary embolism severe symptoms may occur, such as:

  1. Shortness of breath , which may worsen gradually or suddenly
  2. Chest pain that may get worse when you breathe
  3. Sudden collapse

Both deep vein thrombosis and pulmonary embolism are serious diseases that require urgent investigation and treatment.


Diagnosis of deep venous thrombosis

No physical examination or combination of signs and symptoms is accurate enough to establish the diagnosis of deep venous thrombosis.
Classic calf pain in forced flexion of the foot (Homan’s sign) is an effective test but is present in only half of patients with deep venous thrombosis.
Discomfort in the calf muscles in forced flexion of the foot with the right knee was declared as the sign of deep venous thrombosis.
However, the Homans signal is found in at least 50% of patients without deep venous thrombosis.
Superficial thrombophlebitis is characterized by the discovery of a palpable, hardened, subcutaneous and rope-like venous segment.

Forty percent of patients with superficial thrombophlebitis, without varicose veins  or other obvious causes (eg intravenous catheters, intravenous drug abuse, soft tissue injuries, etc.) have DVT.
Patients with superficial thrombophlebitis extending to the saphenofemoral junction have an increased risk of associated deep vein thrombosis.

The clinical diagnosis of deep venous thrombosis is difficult.
Current diagnostic techniques have advantages and disadvantages.
Most commonly performed diagnostic exams include color Doppler ultrasonography and magnetic resonance imaging (MRI).
Venography is rarely used, it is an outdated exam.

It may be very accurate to identify the formation of blood clots. Acoustic waves come out of the inner structures of the leg and create images that reveal any abnormality.

Magnetic Resonance Magnetic
resonance imaging is particularly effective in the diagnosis of deep venous thrombosis in the pelvis and thigh.
This technique is used more and more because it is not invasive and allows simultaneous visualization of both lower limbs.

The differential diagnosis of deep venous thrombosis

The doctor must exclude the following conditions:


Treatment for deep venous thrombosis

At first you have to be at rest, avoid physical exertion and sports, but keep your leg in motion.
The doctor prescribes medicines to fluidize the blood (anticoagulants).
This way, you prevent the formation of clots or prevent the old ones from growing.
With pharmacological therapy, existing clots can not be dissolved.
Generally, the first medicine your doctor recommends is heparin.
If administered intravenously, the patient should remain in the hospital.

The newer forms of heparin can be taken with an injection once or twice a day.
You may not need to stay in the hospital if you take this new form of heparin.
Usually, a drug called warfarin (Coumadin) is taken along with heparin.
Warfarin is taken by mouth.
The dosage of the anticoagulant should be determined by the physician, according to the prothrombin time.
You usually have to take warfarin for one to three months but in severe cases, the duration of treatment is longer or even for a lifetime.
When you take warfarin, you are more likely to develop bleeding, even doing activities that you do every day. If you are taking warfarin at home:

  • Take this medication only with the times and doses prescribed by your doctor.
  • Ask your doctor what you should do if you forget a dose
  • Perform blood tests often to make sure you are taking the right dose
  • It is necessary to know  how and when to take other medicines to avoid side effects.

Finding ways to check for possible problems caused by warfarin
Are developing new oral anticoagulant drugs.


Natural Remedies

Your doctor may recommend elastic compression stockings for use on one leg or both, as well as other instructions to hold the limb without supporting the weight.
The elastic compression stocking improves blood flow in the legs and reduces the risk of complications such as blood clots.
It is important to wear socks throughout the day.
The healing time depends on the condition of the blood vessels, the underlying cause and the therapies performed.


Surgery for deep venous thrombosis

In rare cases, you may need surgery if the medicines do not work.
There are two types of surgeries:

  • Insert a filter into the larger vein in the body to prevent the emboli from traveling to the lungs
  • Removal of the thrombus from the vein


Prognosis for deep venous thrombosis

Deep venous thrombosis usually goes away without consequences, but it may come back. Some people may have pain and swelling in the leg for a long time called thrombotic syndrome.
Among the consequences, you may notice a discoloration of the skin.
These symptoms may appear immediately but may also develop one year later.
Using tight (compression) socks even after deep vein thrombosis has passed may help prevent this problem.
Blood clots in the thigh are those that come more easily and travel to the lungs (resulting in a pulmonary embolism) compared to thrombi of the lower leg, upper limbs, or other parts of the body.

Death occurs in approximately 6% of cases of deep vein thrombosis and in 12% of cases of pulmonary embolus within one month of diagnosis.
The long-term outcome is usually good if it is not associated with a malignant tumor.


Prevention of deep venous thrombosis

Prevention of deep vein thrombosis is much easier than treatment after it occurs.
Some preventive measures include the following remedies:
Diet is essential to help prevent the formation of blood clots, omega-3s reduce the level of cholesterol and triglycerides in the blood, also foods rich in fiber reduce the absorption of fats in the small intestine and give a feeling of satiety.


Diet rich in fruits and vegetables

It is important to follow a diet rich in antioxidants (vitamins A, C, E) with plenty of fruits and vegetables to preserve blood vessels.
You have to know how much vitamin K you are eating when you take blood thinners.
The vitamin K can affect the efficacy of drugs such as warfarin. Foods rich in vitamin K are green leafy vegetables and canola or soybean oils.
Take the prescribed medications exactly as directed by your doctor.
When you perform an operation, such as an orthopedic operation, you will probably have to take anticoagulants during hospitalization.
Perform the exercises with the calf muscles if you sit for a long time. Whenever possible, you should get up and walk.
If you can not get up and take a walk you can simply lift and lower your heels, keeping your toes on the ground, you can lift your toes while your heels remain in contact with the ground.
Passive mobilization is not necessary because you need muscle contraction to push venous blood into the heart.

Movement . If you spend a lot of time in bed due to surgery or for other reasons, it is best to move as fast as possible, so the risk of developing blood clots is lower.

Make changes in lifestyle . Lose weight, stop smoking and control your blood pressure. Obesity, smoking, and high blood pressure increase the risk of deep venous thrombosis.
Use compression stockings to help prevent the formation of blood clots in the legs if your doctor recommends.

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