Pulmonary edema is an abnormal buildup of fluid in the air sacs of the lungs, which leads to shortness of breath.

Lung congestion; Lung water; Pulmonary congestion

Pulmonary edema is often caused by congestive heart failure. When the heart is not able to pump blood to the body efficiently, it can back up into the veins that take blood through the lungs to the left side of the heart.

As the pressure in these blood vessels increases, fluid is pushed into the air spaces (alveoli) in the lungs. This fluid reduces normal oxygen movement through the lungs. This and the increased pressure can lead to shortness of breath.

Congestive heart failure that leads to pulmonary edema may be caused by:

• Heart attack, or any disease of the heart that weakens or stiffens the heart muscle (cardiomyopathy)
• Leaking or narrowed heart valves (mitral or aortic valves)
• Sudden, severe high blood pressure (hypertension)

Pulmonary edema may also be caused by:

• Certain medications
• High altitude exposure
• Kidney failure
• Narrowed arteries that bring blood to the kidneys
• Lung damaged caused by poisonous gas or severe infection
• Major injury

Symptoms of pulmonary edema may include:

• Coughing up blood or bloody froth
• Difficulty breathing when lying down (orthopnea) -- you may notice the need to sleep with your head propped up or use extra pillows
• Feeling of "air hunger" or "drowning" (if this feeling wakes you from sleep and causes you to sit up and try to catch your breath, it's called "paroxysmal nocturnal dyspnea")
• Grunting, gurgling, or wheezing sounds with breathing
• Inability to speak in full sentences because of shortness of breath

Other symptoms may include:

• Anxiety or restlessness
• Decrease in level of alertness (consciousness)
• Leg swelling
• Pale skin
• Sweating (excessive)

The health care provider will perform a physical exam and use a stethoscope to listen to your lungs and heart. The following may be detected:

• Abnormal heart sounds
• Crackles in your lungs, called rales
• Increased heart rate (tachycardia)
• Pale or blue skin color (pallor or cyanosis)
• Rapid breathing (tachypnea)

Possible tests include:

• Blood chemistries
• Blood oxygen levels (oximetry or arterial blood gases)
• Chest x-ray
• Complete blood count (CBC)
• Echocardiogram (ultrasound of the heart) to see if there are problems with the heart muscle (such as weakness, thickness, failure to relax properly, leaky or narrow heart valves, or fluid surrounding the heart)
• Electrocardiogram (ECG) to look for signs of a heart attack or problems with the heart rhythm

Pulmonary edema is almost always treated in the emergency room or hospital, sometimes in an intensive care unit (ICU).

• Oxygen is given through a face mask or tiny plastic tubes are placed in the nose.
• A breathing tube may be placed into the windpipe (trachea) so you can be connected to a breathing machine (ventilator).

The cause of edema should be quickly identified and treated. For example, if a heart attack has caused the condition, it must be treated immediately.

Medications that may be prescribed include:

• Diuretics, which remove excess fluids from the body
• Medicines to strengthen the heart muscle, control the heartbeat, or relieve pressure on the heart

The outlook depends on the cause. The condition may get better quickly or slowly. Some patients may need to use a breathing machine for a long time. If not treated, this condition can be life-threatening.

Go to the emergency room or call 911 if you have breathing problems.

If you have a disease that can lead to pulmonary edema or a weakened heart muscle, take all prescription medications as instructed. Following a healthy diet, one low in salt and fat, can significantly reduce the risk of developing this condition.

Massie BM. Heart failure: pathophysiology and diagnosis. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 58.

Matthay MA, Martin TR. Pulmonary edema and acute lung injury. In: Mason RJ, Broaddus VC, Martin TR, et al. Murray & Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 55.

McMurray JJV, Pfeffer MA. Heart failure: management and prognosis. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 59.