A number of things can cause pulmonary edema or lung congestion, but most are related to the way your heart pumps blood. (1) Depending on the cause, the signs and symptoms of pulmonary edema may appear suddenly or slowly over time. If it comes on acutely, pulmonary edema is a 911 situation and can be life-threatening.

Types of Pulmonary Edema

There are two main types of pulmonary edema, based on what is causing the lungs to fill up with fluid. One is cardiogenic edema, which results from increased pressures in the heart. The other is noncardiogenic, which can be caused by a number of conditions that damage the lungs. Heart-Related (Cardiogenic) Edema Heart-related edema is caused by increased pressures in the heart. According to Penn Medicine, congestive heart failure is a common cause of this type of pulmonary edema. (2) When you develop congestive heart failure, the left ventricle of your heart stops working properly, causing the kidneys to filter less fluid out of the circulation into the urine. This increases pressure in the capillaries (small blood vessels) of the lungs and causes excess fluid to be pushed into the air sacs of the lungs, the liver, and the legs. According to the American Heart Association (AHA), the most common causes of congestive heart failure include:

Coronary artery diseaseHigh blood pressurePrevious heart attackCardiomyopathyRenal artery stenosisKidney disease (3)

Noncardiogenic Pulmonary Edema  In noncardiogenic pulmonary edema, the lungs fill up with fluid because the capillaries become leaky, causing fluid to collect in the alveoli (tiny air sacs in the lungs). (4) Some factors that can cause noncardiogenic pulmonary edema include:

Acute respiratory distress syndrome (ARDS)PneumoniaSepsisTraumaNear-drowningAdverse drug reactionPulmonary embolismSmoke inhalationInhalation of toxins like heroin (5)Organ failure (kidney, liver) (4)

High-Altitude Pulmonary Edema (HAPE) Aside from medical conditions, hikers and mountain climbers are at risk for pulmonary edema that’s caused by rapid altitude ascent, generally above 8,000 feet. (6) HAPE may lead to shortness of breath, coughing, rapid heart beat, and decreased oxygen levels as a result of pressure from constricted pulmonary capillaries. Other risk factors for HAPE include genetic susceptibility and having smaller lungs. (6) To prevent HAPE, it is recommended to make gradual ascensions to higher heights. Mayo Clinic recommends climbing no more than 1,000 to 1,200 feet a day after you reach 8,200 feet. Climbers may also take medications like acetazolamide or nifedipine the day before ascent to reduce blood pressure and prevent motion sickness. (6)

Signs and Symptoms of the Condition

The symptoms you should look out for include:

Difficulty breathing or shortness of breath that worsens with activity or laying downA cough that produces a frothy sputum sometimes containing bloodHeart palpitationsBlue-tinged lips or bodyWheezing or suffocatingAnxiety or restlessnessCold, clammy, pale skinExcessive sweatingChest pain (4,5)

If your pulmonary edema is chronic, the symptoms are less severe, but will occur more frequently. They include:

Shortness of breath, especially when physically activeDifficulty breathing when you’re lying downRapid weight gainWheezing or coughingSwelling in your lower extremities Fatigue (5)

How Doctors Diagnose Pulmonary Edema

If you think you may be experiencing symptoms of acute pulmonary edema, this is an emergency and you should seek medical attention straight away. To receive a diagnosis of pulmonary edema, your healthcare provider will listen to your lungs and heart with a stethoscope for rapid breathing or an abnormal heartbeat. Your doctor may order a blood test to determine your oxygen levels, blood count, kidney function, and/or liver function. (8) Your doctor may also obtain an electrocardiogram, echocardiogram, ultrasound, X-ray, or CT scan of the heart and chest to check the condition of the heart and evaluate for any fluid in the lungs. (8)

Options for Treating ‘Wet Lung’

Without proper treatment, pulmonary edema can be fatal. Treatment of acute pulmonary edema may include:

Oxygen A diuretic administered through an IV Nitrate medicationsPlacement in an upright position (1)

Treatment will also depend on what’s causing your pulmonary edema. If it’s a circulatory problem, then the treatment will be focused on improving the heart’s pumping function and the kidneys ability to remove excess fluid. If the cause of your pulmonary edema is noncardiogenic like ARDS or pneumonia, your healthcare provider will treat the condition that’s producing fluid with medication and an oxygen mask. (2) If you’re climbing at a high altitude and develop mild symptoms of HAPE, you can find relief by descending 1,000 to 3,000 feet, although more severe symptoms may require an oxygen mask and immediate medical attention. (2)

How to Prevent Pulmonary Edema

Since cardiovascular disease is the number one cause of pulmonary edema, maintaining heart health is key to prevention. There are a number of lifestyle changes you can make to prevent the condition, including:

Controlling your blood pressure Starting at 20, the AHA recommends getting your blood pressure checked every two years if it’s below 120/80 mm Hg. (9) You can also control your blood pressure by maintaining a healthy weight, exercising, and reducing sodium in your diet. (10)Watching your cholesterol Your total cholesterol should be less than 200 mg/dl. If you’re at risk for cardiovascular disease, your low-density lipoprotein (LDL) cholesterol should be less than 100 mg/dl, and your triglycerides should be no more than 150 mg/dl. (11) Keep your cholesterol low by reducing trans fats and saturated fats, quitting smoking, exercising, and reducing stress levels.Eating a heart healthy diet, like the Mediterranean diet This diet includes eating seafood, whole grains, healthy fats, and fruits and vegetables. Research shows that a Mediterranean diet can reduce cholesterol and can cut your risk of developing heart disease.Reducing your salt intake Excess salt can lead to water retention, so it’s best for those with pulmonary edema to go on a low-salt diet to minimize fluid retention. (12) To reduce your consumption of salt, check food labels for salt content, buy fresh foods, and avoid adding table salt to your food.Exercising The AHA recommends at least 30 minutes of moderate-intensity aerobic activity five days a week, or 25 minutes of high-intensity aerobic activity three days a week. (13) Some exercise options include walking, jogging, cycling, yoga, or swimming. You can also try lifting weights, getting a personal trainer, or doing group exercise classes.Maintaining a healthy weight Make sure you stay within a healthy body mass index (BMI) range for your age, height, and weight. Excess abdominal fat places you at risk for a number of diseases, like type 2 diabetes, coronary artery disease, and high blood pressure. (14)