Pulmonary embolism: overview and more

Pulmonary embolism (PE) is caused by a blood clot that lodges in the pulmonary artery , the main blood vessel that leads to the lungs, or in one of its branches .

A blood clot gets stuck in the pulmonary artery.

PD usually occurs when a blood clot in the legs, a condition called deep vein thrombosis (DVT), travels and travels to the blood vessels in the lungs. Symptoms of PD include shortness of breath, chest pain, and hemoptysis .

Pulmonary embolism symptoms

The pulmonary artery does the fundamental job of bringing blood to the lungs for oxygen replacement, so obstruction of blood flow within this blood vessel affects the lungs and heart and causes symptoms of oxygen starvation in the rest of the body. .

Warning signs to watch out for:

The most common symptoms of pulmonary embolism are:

  • Shortness of breath that starts suddenly, usually a few seconds after PD.
  • Sudden severe chest pain
  • Cough
  • Hemoptysis
  • Pleurisy chest pain that worsens on inspiration.
  • Wheezing
  • Incrise of cardiac frecuency
  • Fast breathing
  • Blue or pale lips and fingers
  • Dizziness or loss of consciousness
  • Signs or symptoms of DVT in one or both legs

The severity of PD is usually determined by the size of the obstacle. If the pulmonary embolism is large, the case is often described as massive PE. This can cause significant blockage of the pulmonary artery, leading to severe cardiovascular disease, dangerous drops in blood pressure, and severe drops in blood oxygen or oxygen deprivation affecting the brain and the rest of the body .

A smaller pulmonary embolism causes less severe symptoms, but still requires a medical emergency that can be fatal if left untreated. Smaller blood clots generally block one of the smallest branches of the pulmonary artery and can completely block a small pulmonary vessel, eventually leading to a lung infarction , which is the death of part of the lung tissue .

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Blood clots called thromboemboli , which cause PE, are usually caused by DVT in the deep veins of the groin or thighs.

DVT and lungs

It is estimated that about 50% of people with untreated DVT will experience pulmonary embolism .

The anatomy of the body is designed in such a way that DVTs tend to get stuck in the lungs. The veins in the legs, where DVT usually forms, fuse when blood returns to the right side of the heart through a large vein, the inferior vena cava (IVC). Blood from the right side of the heart then travels to the lungs through the pulmonary arteries to resume oxygen supply.

When a blood clot travels through the veins in the legs to the heart, all the blood vessels, including the heart, are larger than the veins in the legs. However, when a blood clot enters the lungs, the vessels become smaller and this is where the clots get stuck in one of the pulmonary arteries, leading to PD.

These blood clots can lodge in any of the blood vessels in the lungs. Small blood clots can lodge in the smallest blood vessels in the lungs. Large blood clots accumulate in large blood vessels, disrupting the lungs' ability to adequately oxygenate blood for use throughout the body, with potentially disastrous consequences .

Risk factors for blood clots.

Most people with PD, with or without prior DVT, have a bleeding disorder or condition. The most common causes and risk factors for blood clots are:

  • Immobility due to physical paralysis, prolonged bed rest, or hospitalization
  • Sitting on long car or airplane trips
  • History of postponed pulmonary embolism
  • History of previous blood clots, such as DVT, stroke, or heart attack.
  • Blood clotting disorders
  • Of smoking
  • History of cancer and / or use of chemotherapy.
  • History of the surgery
  • Bone fracture, especially the femur.
  • Obesity
  • Hormone therapy (including hormone replacement therapy)
  • Using birth control pills
  • Recent pregnancy or pregnancy


The diagnosis of PD begins with a clinical evaluation by your healthcare provider and may then include specialized tests that can confirm, confirm, or rule out the diagnosis of PD.

Clinical evaluation

The first step in diagnosing PD is your healthcare provider's assessment of whether your chance of having it is high or low. Your healthcare provider performs this evaluation by taking a complete history, evaluating your risk factors for DVT, doing a physical exam, measuring your blood oxygen concentration, and possibly doing an ultrasound to detect DVT.

Non-invasive tests

After a clinical evaluation by your healthcare professional, you may need special tests, such as blood tests or imaging tests.

  • D-dimer test : If your likelihood of PD is thought to be low, your healthcare provider may order a D-dimer test. A D-dimer test is a blood test that measures whether there has been an abnormal level of activity of clotting in your bloodstream, which is to be expected if you've had DVT or PE. If the clinical likelihood of PD is low and your D-dimer test is negative, PD can be ruled out and your healthcare provider will consider other possible causes of your symptoms.

If your likelihood of PE is considered high, or if your D-dimer test is positive, a V / Q scan (ventilation / perfusion scan) or a chest CT scan is usually done.

  • V / Q scan: An AV / Q scan is a scan of the lungs that uses a radioactive dye injected into a vein to assess blood flow in the lung tissue. If a pulmonary artery is partially blocked by an embolus, the corresponding portion of the lung tissue receives less radioactive dye than usual.
  • CT : CT is a non-invasive computed radiograph that allows your doctor to view your pulmonary arteries to determine if you have an obstruction caused by an embolus.

Pulmonary angiogram

Pulmonary angiography has long been considered the gold standard for detecting PD, but now there are noninvasive tests that can confirm or exclude the diagnosis. If your diagnosis is unclear, you may need a pulmonary angiogram.

A pulmonary angiogram is a diagnostic test in which a dye is injected through a tube into the pulmonary artery so that any blood clots can be seen on an x-ray. Because pulmonary angiography is an invasive test with risks for complications, your healthcare provider will carefully weigh the risks and benefits before recommending this test.

Watch out

After confirming the diagnosis of pulmonary embolism, therapy begins immediately. If you have a very high probability of pulmonary embolism, medication treatment can be started even before your diagnosis is confirmed.


The main treatment for pulmonary embolism is the use of anticoagulants ("blood thinners") to prevent further clotting of the blood.

Blood thinners commonly used to treat PD are intravenous (intravenous) heparin or a derivative of heparin that can be injected subcutaneously (under the skin), such as arixtra (fondaparinux). The heparin family of drugs provides an immediate blood-thinning effect and helps prevent further blood clots.


When PE is large or causes cardiovascular instability, anticoagulant therapy is often insufficient. In these situations, powerful clot-busting agents called thrombolytics can be given to dissolve the blood clot . These medications, which contain fibrinolytic agents such as streptokinase, are designed to dissolve a blood clot that is blocking the pulmonary artery .

Thrombolytic therapy carries a significantly higher risk than anticoagulant therapy, including a high risk of serious bleeding . If a pulmonary embolism is severe enough to be life-threatening, the potential benefits may outweigh the risks of these treatments.

Treatment guidelines published by the American Society of Hematology in 2020 recommend that patients with chronic PD be encouraged to first take blood clot busting medications and then take anticoagulants indefinitely, rather than stopping therapy with anticoagulants after initial treatment. Your healthcare provider will continually assess the risks and benefits to you.


Surgery is a direct removal method for PE. The most common surgical procedure, called an embolectomy, is risky and not always effective, so it is intended for people who have very little chance of survival without it .

Front facing

After the initial stage of PD, you may need a long-term plan to prevent more PD from occurring, and you may need to adjust to the consequences of PD if it has caused irreversible damage.


You may need to take an oral (by mouth) anticoagulant medicine for months or even years after you have received urgent treatment with an intravenous anticoagulant or an injectable blood clotting agent. Traditionally, Coumadin (warfarin) has been the drug of choice, but in recent years, the newer blood thinners, Eliquis (apixaban), Xarelto (rivaroxaban), Savaisa (edoxaban), and Pradaxa (dabigatran), have long been widespread. . prevention of recurrence of PD .

IVC filter

If you develop recurrent PE despite taking a blood thinner, you may need to place a filter in your inferior vena cava, which is a large abdominal vein that connects your lower body to your heart. The IVC filter can trap more clots that can escape from the veins in the legs before they reach the lungs. The same goes for complications like significant bleeding from taking blood thinners.

Pulmonary monitoring and rehabilitation

If you experience relapses of PD, you can develop long-term consequences, such as pulmonary hypertension or pulmonary infarction (death) of part of the lung .

If you experience these complications, you may need to see a pulmonologist to monitor your respiratory function and treat if necessary.

Get the word of drug information

Pulmonary embolism is most often seen in people with a condition or condition that predisposes to DVT.

If you have symptoms that suggest a pulmonary embolism, such as sudden, unexplained shortness of breath or chest pain, it's important to see your doctor right away.

In general, PD is a relatively common disease, the results of which improve significantly with prompt treatment.

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