Medically reviewed by Nachiket J. Patel, MD, FACC, FSCAI. Last reviewed July 2026.
A pulmonary embolism, or PE, occurs when a blood clot travels to the lungs and blocks blood flow. It can strain the right side of the heart, reduce oxygen delivery, and become life-threatening without warning.
Possible PE symptoms require emergency assessment. Flow Heart & Vascular does not provide emergency evaluation or inpatient pulmonary embolism thrombectomy. Do not schedule an office visit or wait for a callback when an acute PE may be occurring.
Call 911 for sudden unexplained shortness of breath, sharp chest pain, coughing blood, fainting, severe weakness, or a rapid heartbeat with significant symptoms.
What symptoms can pulmonary embolism cause?
Symptoms vary with the amount and location of clot and the patient’s heart and lung health. A smaller clot can still be clinically important, and severe symptoms can occur without obvious leg swelling.
- Sudden shortness of breath
- Chest pain that may worsen with a deep breath
- A fast or irregular heartbeat
- Coughing blood
- Lightheadedness, fainting, or new confusion
- Unexplained low oxygen level
- One-sided leg swelling or pain suggesting deep vein thrombosis (DVT), a blood clot in a deep vein
What should I do if PE is possible?
Call 911. Emergency clinicians can check oxygen level, blood pressure, heart strain, and alternative diagnoses. Do not drive yourself if you are breathless, faint, or unstable.
An outpatient ultrasound or cardiology appointment cannot safely rule out an acute pulmonary embolism. The diagnosis may require urgent laboratory testing and chest imaging available in an emergency setting.
How is pulmonary embolism diagnosed in the hospital?
The hospital team combines symptoms, examination, risk, and testing. A computed tomography (CT) scan using injected contrast to show the lung arteries is commonly used; this is called CT pulmonary angiography. In certain situations, the team may use a ventilation-perfusion (V/Q) scan, which compares air movement and blood flow in the lungs.
Blood tests, electrocardiography, and echocardiography can help assess strain and severity but do not replace the full evaluation. Leg ultrasound may identify the source DVT.
How is PE treated?
Anticoagulation, treatment with medicine that reduces blood clotting, is the main treatment for many pulmonary emboli (blood clots in the lungs). Patients with shock or other high-risk findings may need advanced hospital treatment selected by an emergency, critical-care, pulmonary, interventional, or surgical team.
The treatment and setting depend on blood pressure, oxygen needs, heart strain, the amount and location of clot, bleeding risk, and other illnesses. Those decisions must be made urgently in a hospital, not through an outpatient web page.
What follow-up may be needed after emergency treatment?
After discharge, follow the hospital team’s instructions for anticoagulation, activity, and specialist care. Do not skip or stop an anticoagulant without medical guidance.
Scheduled follow-up may address the source DVT, duration of anticoagulation, persistent breathlessness, recurrent-clot risk, post-thrombotic symptoms, and whether a pelvic venous obstruction contributed.
For non-urgent follow-up after hospital evaluation, patients may contact Flow Heart & Vascular. New or worsening emergency symptoms still require 911.
Frequently asked questions
Can pulmonary embolism be diagnosed in a cardiology office?
An office may recognize concerning features, but suspected acute PE generally requires emergency testing and treatment in a hospital setting.
Can PE occur without leg pain?
Yes. A DVT may be silent, and some pulmonary emboli occur without noticeable leg symptoms.
If symptoms improve, can I wait?
No. PE symptoms can fluctuate. Sudden unexplained breathlessness, chest pain, coughing blood, or fainting still warrants emergency evaluation.
Sources and further reading
Related heart and vascular information
- Deep Vein Thrombosis (DVT)
- Vascular Ultrasound Testing (Arterial, Venous, Carotid)
- May-Thurner Syndrome
Non-urgent follow-up at Flow Heart & Vascular
For a stable concern or follow-up after emergency or hospital care, contact Flow Heart & Vascular in Mesa. Call 911 for new or worsening emergency symptoms.
This page provides general education and does not replace individualized medical advice.
About this patient guide
This guide provides general education to help you prepare for a conversation with your care team. The sources and further reading link to additional information from medical organizations.
A medical-review date refers to review of the clinical information. Wording, formatting, and link updates do not by themselves change that date. Your own care depends on your symptoms, medical history, and discussion with your clinician.
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