Pulmonary edema is an abnormal accumulation of extravascular fluid in the alveoli in the lungs. The condition affects gas exchange in the lungs, leading to shortness of breath. If it progresses, it might cause respiratory failure.

Pulmonary edema can either be acute or chronic. If it’s acute (occurs suddenly), patients need to seek medical help immediately. Cardiogenic or non-cardiogenic processes cause it, but more on that in the article.

It’s essential to learn about the causes, symptoms, and risk factors of pulmonary edema to understand better how to manage the condition. Below, you will learn everything about pulmonary edema. So, let’s begin!

What Is Pulmonary Edema?

The lungs contain tiny air sacs or alveoli, which pick up oxygen and release carbon dioxide with each breath. Typically, the air sacs have a thin wall that facilitates air exchange and keeps out fluid.

But sometimes, these walls lose their integrity for several reasons, like exposure to medication or toxins, pneumonia, heart diseases, injury to the chest, or traveling to high-altitude areas. As a result, excess fluid seeps out of blood vessels and fills the alveoli instead of air.

This prevents oxygen from getting absorbed into the bloodstream and carbon dioxide from being extracted. Therefore, an individual might experience shortness of breath and sometimes respiratory failure. If this occurs, the patient is said to have Pulmonary Edema.

Symptoms

Depending on the type of pulmonary edema, its symptoms might be acute (develop suddenly) or chronic (develop over time).

Acute pulmonary edema signs and symptoms include:

Anxiety or restless
Rapid, irregular palpitations
Gasping for breath
A feeling of drowning or suffocations
Breathing problem or extreme shortness of breath that worsens with every activity you do
A cough coupled up with frothy sputum and blood

Chronic pulmonary edema signs and symptoms

Breathing problems when exercising or lying on a flat surface
Wheezing
Fatigue
Worsening cough
Shortness of breath than normal
Unexplained weight gain
Waking up at night with cough or breathless

You can also develop pulmonary edema when traveling to or exercising in high-altitude areas. This condition is known as High-altitude pulmonary edema or HAPE, and often involves the following signs and symptoms:

Chest pain
Dry cough
Headache
Shortness of breath, which worsens over time
Low-grade fever
Weakness
After a while, you might develop a cough accompanied by froth and pink sputum.
Reduced ability to exercise as you would normally do

Causes

As said in the introduction, pulmonary edema either occurs because of the cardiogenic process or the non-cardiogenic process. So when a cardiogenic process causes it, it’s referred to as cardiogenic pulmonary edema and vice versa.

Cardiogenic Pulmonary Edema

This condition occurs because of heart-related (cardiogenic) problems. Congestive heart conditions can weaken the left ventricle, causing it to work more than normal to pump blood coming from the lungs.

As a result, pressure builds up in the heart and other parts of the circulatory system, pushing fluid through the blood vessel wall into the air sacs. Common heart-related conditions that might cause pulmonary edema include:

Coronary artery disease
Cardiomyopathy
Heart valve problems
Inflammation of the heart muscle
Congenital heart defect
Arrhythmias
High blood pressure, severe heart attack
Kidney disease
Chronic health conditions like hemochromatosis and amyloidosis

Non-cardiogenic Pulmonary Edema

Pulmonary edema occurs not because of increased pressure in the heart but other conditions, including:

ARDS (acute respiratory distress syndrome) – A severe lung inflammation caused by widespread infection (sepsis), severe bleeding, severe injury, or pneumonia.
Drug overdose or adverse drug reaction – Drugs like cocaine and heroin can cause the condition.
Pulmonary embolism
Inhaling certain toxins or breathing in some of your stomach contents when vomiting
High-altitudes
Near drowning–Inhaling water causes fluid buildup in the lungs.
Negative pressure edema
Smoke inhalation
Transfusion-related lung injury
Viral infections

Sometimes, both cardiogenic and non-cardiogenic causes can lead to pulmonary edema.

Risk Factors

Heart-related problems lead to increased pressure in the heart. Therefore, increasing the risk of fluid filling the lungs. Below, we have listed a few heart failure risk factors:

Diabetes
Sleep apnea
Arrhythmias
Coronary artery disease
Heart valve
Congenital heart disease
Excessive smoking and alcohol use

Additionally, near drowning, viral infections, pulmonary embolism, and lung injury can increase pulmonary edema risk. Also, people who love to venture into high-altitude areas might be at the risk of getting high-altitude pulmonary edema (HAPE).

Complications

Depending on the cause of the pulmonary edema, patients might end up developing the complications below:

Pleural effusion–Fluid buildup in membranes surrounding the lungs
Congestion of the liver and sometimes swelling
Swollen legs, abdomen, and feet
Increase breathing difficulty

Diagnosis

If your doctor suspects you have pulmonary edema, he will conduct a physical exam. The specialist will place a stethoscope on your chest and listen for palpitations, rapid breathing, and crackles in the lungs.

For confirmation, you might have to undergo several tests and exams, including:

Blood test to determine your oxygen levels, liver function, kidney function, electrolyte levels, and blood count.
Electrocardiogram (EKG), echocardiogram, and a heart ultrasound to check your heart condition.
Chest X-ray and CT scan to check if there’s any fluid in your lungs and determine the size of your heart

Treatment

Pulmonary edema treatment depends on the cause and severity. If you’re experiencing breathing difficulty, you’ll receive oxygen immediately to increase your oxygen levels. The doctor might place tubes inside your nostril or a face mask on your face to help you take in oxygen.

Doctors recommend diuretics (water pills) for cardiogenic pulmonary edema in most cases. These medications reduce pressure on the heart and lungs. You might also receive other oral medications to strengthen your heart muscles. However, if your condition is severe and you’re not responding to oral medications, then you might get hospitalized. The physician will then administer the diuretic medication intravenously.

If you have non-cardiogenic pulmonary edema, the specialist will try to establish the cause and provide your proper medication based on it. For instance, you will receive antibiotics for severe infections (sepsis).

Prevention

Like treatment, prevention depends on the cause of the pulmonary edema. However, you can do a few things to reduce the risk of pulmonary edema. They include:

Reducing salt intake
Eating food rich in fresh fruits, whole grains, fat-free or low-fat dairy products
Avoid smoking
Limit alcohol intake
Manage stress
Maintaining a healthy body weight
Avoidance of drug overdose
Slow elevation to high altitude to allow the lungs to acclimate

But keep in mind you cannot avoid some causes like ARDS because of an overwhelming infection or a trauma.

Final Thoughts

That marks the end of our article. Although pulmonary edema is a treatable and preventable condition, it might prove life-threatening life if left untreated.