Pulmonary embolism (PE) is a serious, sometimes life‑threatening condition where a blood clot (or, rarely, other material) blocks an artery in the lungs. You’re asking “how do you get” one, so I’ll focus on causes and risk factors, plus what to do to protect yourself.

This is not something to experiment with or “try to get.”
If you’re worried you might have a PE, call emergency services or go to an ER immediately.

What is a pulmonary embolism?

  • A pulmonary embolism usually happens when a blood clot forms in a deep vein (often in the leg), breaks off, travels through the bloodstream, and lodges in an artery in the lungs.
  • This process (clots in veins that can move to the lungs) is called venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism.
  • Less commonly, the blockage can be from other things like fat, air bubbles, or tumor fragments, usually in the setting of serious trauma or advanced disease.

Think of it like a plug that suddenly blocks blood flow in part of the lungs, which can strain the heart and reduce oxygen levels.

How do you “get” a pulmonary embolism?

You don’t “catch” a PE like an infection; it develops from blood clots , mainly in the deep veins of the legs or pelvis, that then travel to the lungs.

Main medical pathway

  1. A clot forms in a deep vein (often in the leg or pelvis) → deep vein thrombosis (DVT).
  1. Part of the clot breaks off (embolus) and travels through the veins, heart, and into the pulmonary arteries.
  1. The embolus lodges in a lung artery, blocking blood flow to part of the lung → pulmonary embolism.

In most people, this only happens when risk factors for clotting are present.

Major risk factors and triggers

Experts often group risk factors using the idea of Virchow’s triad : things that make blood clot more easily (hypercoagulability), slow blood flow (stasis), or injure the vein wall (endothelial injury).

1. Things that slow blood flow (stasis)

These increase the chance a clot forms in the deep veins:

  • Long‑term bed rest (illness, hospital stay, plaster casts, being largely immobile for several days).
  • Long travel (plane, car, train rides usually over 4 hours) with sitting still and little leg movement.
  • Paralysis or very limited mobility after stroke, injury, or surgery.

2. Things that make blood clot more easily (hypercoagulability)

  • Inherited clotting tendencies (thrombophilias) like factor V Leiden, prothrombin gene mutation, protein C or S deficiency, etc.
  • Cancer (especially metastatic or certain types like pancreatic, lung, gastric, hematologic, brain).
  • Estrogen‑containing birth control pills or hormone replacement therapy, especially with smoking or obesity.
  • Pregnancy and the postpartum period, when blood is naturally more prone to clot.
  • Some medical illnesses: heart failure, heart attack, certain kidney diseases, some autoimmune clotting disorders (e.g., antiphospholipid syndrome).
  • Severe infections, including pneumonia and, in some cases, severe COVID‑19.

3. Injury to veins or major trauma

  • Major surgery, especially orthopedic (hip, knee replacements, major fractures).
  • Serious injuries: broken hip or leg, big burns, major accidents.
  • Central venous catheters or devices placed in large veins.

4. Lifestyle and other factors

  • Obesity.
  • Smoking, especially with other risk factors like estrogen therapy.
  • Older age, particularly combined with other risks.
  • Varicose veins and some chronic venous problems.
  • Previous DVT or PE (big red flag for recurrence).

When several factors occur together (e.g., surgery + bed rest + age + estrogen medications), the risk stacks up significantly.

Rare non‑clot causes

Though most PEs are blood clots , there are rare types where other material blocks the lung arteries:

  • Fat embolism – often after severe fractures of large bones like the femur.
  • Air embolism – from certain invasive procedures or trauma.
  • Tumor emboli – bits of tumor in advanced cancers.

These are not typical in otherwise healthy people and usually occur in hospital or trauma settings.

Warning signs to take seriously

You asked “how do you get” one, but knowing symptoms is crucial so you know when to seek help:

  • Sudden shortness of breath or difficulty breathing.
  • Sharp chest pain that may worsen with deep breaths or coughing.
  • Fast heart rate, feeling lightheaded, fainting, or sudden collapse.
  • Coughing up blood (not always present).
  • Signs of DVT in a leg: swelling, pain, warmth, redness in one calf or thigh.

Any combination of sudden unexplained breathlessness, chest pain, or collapse is an emergency and should be treated as such.

Prevention and protection

You can’t control everything, but many risk factors are manageable:

  • Stay mobile :
    • Get up and walk frequently on long trips (every 1–2 hours if possible).
    • Do calf exercises and ankle circles while seated.
  • After surgery or injury:
    • Follow doctor’s instructions about walking early, using compression stockings, or taking blood thinners.
  • Manage long‑term risks:
    • Keep a healthy weight, avoid smoking, and control conditions like diabetes and high blood pressure.
  • Discuss medications:
    • If you use estrogen‑containing birth control or hormone therapy and have clot risk factors (family history, smoking, past clot), talk to a clinician about safer options.

If you’ve ever had a clot or know you have a clotting disorder, regular follow‑up with a healthcare professional is essential.

A quick story‑style example

Imagine a person who flies long‑haul for work. They take a 10‑hour flight, sit in a window seat, hardly move, and are a bit overweight, on estrogen‑containing birth control pills, and have a family history of clots. During the flight and after arrival, blood moves slowly through their leg veins and their blood is more prone to clot. A clot forms in a deep leg vein (DVT), then a piece breaks off and travels to the lungs, causing sudden shortness of breath and chest pain: a pulmonary embolism.

That is the kind of real‑world chain of events behind “how you get a pulmonary embolism.”

If you’re asking for yourself

If you’re worried you might have risk factors or symptoms:

  • If you have sudden shortness of breath, chest pain, or fainting , seek emergency care immediately.
  • If you’re just concerned about your risk (family history, on hormones, long trips, upcoming surgery), book an appointment with a healthcare professional to discuss personal prevention.

Required note

Information here is for general education, not a diagnosis or treatment plan. It’s based on publicly available medical sources and forum‑accessible health information. Information gathered from public forums or data available on the internet and portrayed here.