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Respiratory / CardiovascularEmergency

Pulmonary embolism

A pulmonary embolism is a sudden blockage in a lung artery, usually caused by a blood clot that travels from the legs. It is a critical condition that requires immediate medical attention to prevent lung damage or heart failure.

Severity
Emergency
System
Cardiopulmonary
Progression
Sudden
Treatable
Yes — with urgent treatment
Common age
All ages
Duration
Acute
Contagious
No
Emergency risk
High
Heart & lungs
Affected: Shortness of breath
Affected area: Cardiopulmonary

Overview

A pulmonary embolism is a sudden blockage in a lung artery, usually caused by a blood clot that travels from the legs. It is a critical condition that requires immediate medical attention to prevent lung damage or heart failure.

Understand this condition

The lungs depend on a steady flow of blood to pick up oxygen for the rest of the body. When a clot lodges in a lung artery, it acts like a dam, stopping blood from reaching lung tissue. This prevents the blood from getting oxygenated and puts dangerous pressure on the heart.

Why it happens

It typically starts as Deep Vein Thrombosis (DVT), where blood pools and clots in a leg vein. If the clot breaks loose, it travels through the heart and gets stuck in the narrow vessels of the lungs. This progression can happen rapidly after periods of immobility or injury.

Real-world scenarios

  • This often appears as sudden shortness of breath after a long flight.
  • People may notice sharp chest pain that worsens with deep breathing.
  • This often appears as calf swelling followed by rapid heart rate.
  • People may notice a persistent cough that produces bloody mucus.

Common vs serious explanations

Common
  • Intercostal muscle strain from heavy lifting or exercise
  • A panic attack causing rapid breathing and chest tightness
  • Pleurisy caused by a minor viral infection
  • Bronchitis causing sharp pain while coughing
Serious
  • Myocardial infarction or heart attack causing acute chest pressure
  • Pneumothorax where a lung collapses suddenly
  • Aortic dissection involving a tear in the main artery
  • Pneumonia causing severe respiratory distress and low oxygen

Causes

  • Deep vein thrombosis (DVT)
  • Blood clots traveling from legs to lungs
  • Surgery or trauma recovery
  • Long periods of immobility

Risk factors

  • Recent surgery or hospitalization
  • Cancer and certain treatments
  • Smoking and obesity
  • Extended travel or bed rest
  • Pregnancy or oral contraceptives

How it progresses

3 stages
  1. Onset
    Sudden, severe symptoms — minutes matter.
  2. Critical window
    Time-sensitive treatment dramatically changes outcome.
  3. Recovery
    Long-term recovery and rehabilitation.

How it's diagnosed

  • CT pulmonary angiogram (CTPA)
  • D-dimer blood test
  • Ventilation-perfusion (VQ) scan
  • Chest X-ray and ECG

Treatment options

General educational information only — no dosage advice. Always follow guidance from a qualified clinician.

Medical
  • Anticoagulant medications (blood thinners)
  • Thrombolytic therapy (clot-busting drugs)
  • Surgical clot removal (embolectomy)
  • Insertion of a vena cava filter
Home care
  • Taking prescribed blood thinners consistently
  • Wearing compression stockings
  • Engaging in gentle movement as advised
  • Monitoring for signs of bleeding

Complications

  • Long-term damage if untreated
  • Heart strain
  • Reduced oxygen delivery
  • Risk of cardiac event
  • Recurrence of pulmonary embolism

Prevention

  • Don't smoke
  • Stay physically active
  • Manage blood pressure and cholesterol

When to seek help

Urgent — same-day care
  • Symptoms persist beyond a few days
  • Symptoms interfere with daily activities
  • New or worsening symptoms appear
  • Concerning changes related to pulmonary embolism
🚨 Emergency — call now
  • Sudden shortness of breath
  • Sharp chest pain when breathing in
  • Coughing up blood
  • Fainting or severe lightheadedness
  • Rapid or irregular heartbeat

In any emergency, call your local emergency number or go to the nearest emergency department.

Real-world questions

  • Can Pulmonary embolism feel like a heart attack?
  • Can Pulmonary embolism cause headaches?
  • Is Pulmonary embolism reversible?
  • How quickly does Pulmonary embolism progress?
  • Is Pulmonary embolism hereditary?

Frequently asked questions

What causes Pulmonary embolism?

Possible causes of Pulmonary embolism include Deep vein thrombosis (DVT), Blood clots traveling from legs to lungs, Surgery or trauma recovery, Long periods of immobility.

Is Pulmonary embolism dangerous?

Pulmonary embolism can be serious and may require prompt medical attention, especially if symptoms are severe or worsening.

How long does Pulmonary embolism last?

Duration varies between individuals. Many cases improve with appropriate care, while others may persist longer and require ongoing management.

Can Pulmonary embolism go away on its own?

Pulmonary embolism typically benefits from medical evaluation and should not be ignored.

When should I see a doctor about Pulmonary embolism?

Consider seeing a clinician if symptoms are severe, persistent, worsening, or if you have any concerns related to general.

Sources

Information based on general medical references such as:

CDCNHSWHOMedlinePlus

Last reviewed: May 2026

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Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.