Pulmonary Edema vs Pleural Effusion – Causes & Differences

Pulmonary Edema

It is a condition involving fluid buildup in the lungs. This buildup of fluid leads to shortness of breath.


Acute Pulmonary Edema

It is a life-threatening condition which can occur suddenly and at any time during a cardiac catheterization procedure.

Symptoms of acute pulmonary edema include:

  • a rapid, irregular heartbeat;
  • chest pain (if the edema is caused by heart disease);
  • a cough which produces frothy sputum, possibly tinged with blood;
  • restlessness, anxiety, or a sense of general apprehension;
  • gasping for breath or wheezing;
  • a feeling as if you are drowning or suffocating;
  • difficulty breathing or extreme shortness of breath which gets worse when the patient lies down.

Chronic Pulmonary Edema

Symptoms may include:

  • fatigue;
  • swelling in lower extremities;
  • rapid weight gain (when edema is a result of congestive heart failure);
  • waking up at night with a breathless feeling;
  • wheezing;
  • trouble breathing when you’re lying flat or during exertion;
  • being short of breath more frequently than usual when you are active.

High-altitude Pulmonary Edema

Symptoms may include:

  • headaches, that may be the first symptom;
  • shortness of breath after exertion, that progresses to shortness of breath at rest;
  • chest discomfort;
  • a rapid, irregular heartbeat (palpitations);
  • a cough which produces frothy sputum that may be tinged with blood;
  • fever (high temperature);
  • difficulty walking uphill, that progresses to difficulty walking on flat surfaces;
  • a cough.


The condition occurs when fluid accumulates in the air sacs of the lungs. This makes it difficult to breathe. Causes include:

  • blood transfusion;
  • pneumonia;
  • high altitude;
  • brain injuries like stroke, brain bleeding, brain surgery, head injury, seizure, or tumor;
  • sepsis (blood infection);
  • drug overdose;
  • exposure to some chemicals;
  • reaction to certain medications;
  • trauma;
  • inflammation;
  • near-drowning;
  • organ failure which causes fluid accumulation – kidney failure or liver cirrhosis.
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Pulmonary edema is also caused by heart failure. Heart failure may be due to:

  • sudden, severe high blood pressure (hypertension);
  • an abnormal rhythm;
  • leaking or narrowed heart valves;
  • any disease of the heart which stiffens or weakens the heart muscle (dilated cardiomyopathy or hypertrophic cardiomyopathy);
  • a heart attack.

When To Call The Doctor

Call local emergency services immediately for professional medical help if you experience any of the following symptoms:

  • sweating along with breathing difficulties;
  • extreme breathing difficulties;
  • gray or blue skin tone;
  • rapid, irregular heartbeats;
  • chest pain;
  • a cough which produces a pink, frothy mix of mucus and saliva;
  • anxiety related to trouble breathing;
  • inability to breathe.


A healthcare provider can typically diagnose the condition based on a physical exam and the sufferer’s symptoms.

In addition, patients may need the following tests:

  • echocardiogram;
  • a chest x-ray – it is a picture of the heart and lungs;
  • EKG – it is used to see if a heart condition is the cause of the pulmonary edema;
  • blood gases – the patient’s blood is tested for the amount of carbon dioxide and oxygen in it;
  • blood tests – it may help find the cause of the symptoms.


Treatment depends on the underlying cause of the condition.

Pleural Effusion

It is a collection of fluid in the space between the two linings of the lung. Individuals experiencing a pleural effusion must seek immediate professional medical attention since if it is left untreated, it can be life-threatening.

The condition is common, with about 1.5 million cases diagnosed in the US every year.


Symptoms may include:

  • orthopnea – the inability to breathe easily unless the individual is standing erect or sitting up straight;
  • dyspnea (labored breathing or shortness of breath);
  • dry, nonproductive cough;
  • chest pain.
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Complications may include:

  • pleural thickening (scarring of the lining of the lung);
  • air in the chest cavity (pneumothorax) after drainage of the effusion;
  • infection which turns into an abscess;
  • lung damage.


Viral infection is the most common cause of pleural effusion. Other conditions which can cause the condition are:

  • bacterial infections, such as tuberculosis and pneumonia;
  • reactions to certain medications (such as – hydralazine, procainamide, and isoniazid); which can cause a condition similar to systemic lupus erythematosus;
  • chest injuries;
  • autoimmune disorders, like rheumatoid arthritis and systemic lupus erythematosus;
  • heart surgery, particularly coronary artery bypass grafting;
  • lung cancer, including lymphoma;
  • infection from a parasite or fungus;
  • familial Mediterranean fever, a genetic autoinflammatory disorder which usually causes fever and swelling in the lungs or abdomen;
  • inflammatory bowel disease;
  • pulmonary embolism, a blood clot in the blood vessels which go into the lungs;
  • other lung diseases, such as asbestosis, sarcoidosis (an inflammatory disease which affects multiple organs in the body), mesothelioma (a type of cancer which develops from the mesothelium), and lymphangioleiomyomatosis (a condition that affects the kidneys, the lungs, and the lymphatic system).

Risk Factors

Risk factors may include:

  • history of any contact with asbestos;
  • any previous complaint of high blood pressure;
  • drinking alcoholic beverages;
  • smoking tobacco.


The tests most commonly used to diagnose the condition include:

  • pleural fluid analysis;
  • thoracentesis – it is a minimally invasive procedure during which a needle is inserted into the pleural space between the chest wall and the lungs;
  • ultrasound of the chest;
  • computed tomography (CT) scan of the chest;
  • chest x-ray.
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Common treatments include:

  • pleurodesis – it is a procedure that uses medicine to adhere to the lung to the chest wall. It may be done if the fluid builds up in the pleural cavity again after thoracentesis;
  • surgery – it is commonly used to treat malignant pleural effusion;
  • chest draining – the process does not require general anesthesia. It is done by inserting a needle into the pleural space and draining the fluid out of the body.


It can be serious and life-threatening. Most patients require hospitalized treatment. Also, some affected individuals require surgery.

Bottom Line – Pulmonary Edema vs Pleural Effusion

Pulmonary edema is an abnormal buildup of fluid in the lungs. It can result from decompensation of underlying heart failure, acute coronary ischemia, acute valvular disorder, arrhythmia, or acute volume overload. When the condition occurs, the human body struggles to get sufficient oxygen and the patient starts to experience shortness of breath.

Pleural effusion is the build-up of excess fluid between the layers of the pleura outside the lungs. About 1.5 million people are diagnosed in the US every year. When there are cancer cells in the fluid or the condition is related to cancer, it may be called malignant pleural effusion.