Pulmonary oedema (pulmonary edema): symptoms, causes and treatment

Patient.info lists the symptoms below. It says that if you have any of them you should see a doctor, and that if the symptoms come on gradually you should see your GP.

The NHS heart failure page, as heart failure is its commonest cause, also lists coughing up frothy pink phlegm, sudden weight gain, swelling in feet, ankles, legs or tummy, and being more breathless than expected when active.

• Shortness of breath.

• Breathlessness when exercising.

• Difficulty breathing when lying flat (orthopnoea); you may need extra pillows.

• Waking in the night feeling breathless.

• Coughing up blood or bloody froth.

• Anxiety or restlessness, excessive sweating, and a reduced level of consciousness.

• A blue tinge to the lips or fingers.

Patient.info says that if you have sudden or very severe symptoms, especially breathlessness, you should call an ambulance or go to the nearest A&E.

The NHS heart failure page says to call 999 if you have severe difficulty breathing (gasping, choking or not able to get words out), your lips or skin are pale, blue or grey, or someone has passed out and is not responding normally. It says to ask for an urgent GP appointment or call NHS 111 if you are breathless lying down or on everyday activity, are coughing up frothy pink phlegm or have suddenly gained weight. It also says not to drive yourself to A&E.

Patient.info explains that pulmonary means to do with the lungs and oedema means an excessive collection of watery fluid. The fluid collects in the tissues and many air sacs of the lung, making it difficult to breathe.

It is not the same as pneumonia or a pleural effusion. Patient.info says pneumonia is an infection of the lungs, although it can cause pulmonary oedema because infection of lung tissue can cause fluid to build up. A pleural effusion is a collection of fluid in the lining on the outside of the lungs, rather than inside the air sacs.

Patient.info says it is most often caused by heart failure, where the heart is not able to pump blood efficiently. Blood backs up in the vessels through the lungs, pressure rises and fluid is pushed into the air spaces, reducing oxygen movement.

Causes that do not start in the heart include high-altitude exposure, acute respiratory distress syndrome (ARDS), acute kidney injury or chronic kidney disease, lung damage from poisonous gas or severe infection, pulmonary embolism and major injury.

Patient.info describes high altitude pulmonary oedema (HAPE) as a severe form of altitude sickness that occurs in previously healthy people, usually when someone who lives at low altitude travels above 2,500 metres. It is not caused by a heart problem.

Swimming-induced pulmonary oedema (SIPE), also called immersion pulmonary oedema, occurs when you exercise in water, for example swimming or scuba-diving, and has become more frequent with the popularity of triathlons and open-water swimming events.

Patient.info says a doctor will check your pulse, blood pressure and breathing rate and listen to your lungs and heart. Tests may include blood tests, pulse oximetry to measure oxygen levels, a chest X-ray, an echocardiogram (an ultrasound of the heart) and an ECG.

• Blood tests for anaemia, kidney function, salts, signs of a heart attack and natriuretic peptide, which tends to be raised in heart failure.

• Pulse oximetry, a sensor on the fingertip, to monitor blood oxygen.

• Chest X-ray, to look for signs of heart failure or lung problems such as pneumonia.

• Echocardiogram, to look at the heart muscle and valves.

• ECG, to look for signs of a heart attack or rhythm problems.

Patient.info says people with sudden onset pulmonary oedema usually need urgent admission to hospital. Treatment includes oxygen if oxygen levels are low, diuretics to remove excess fluid from the lungs, and other medicines to help the heart work more effectively, usually given through a vein.

The cause needs treating too, for example a heart attack, high-altitude sickness or acute kidney injury. If oxygen and medicines do not work, a ventilator or other breathing support may be used until the pulmonary oedema improves.

Patient.info says the outlook depends on the cause. Pulmonary oedema may get better, either quickly or slowly, but it can be life-threatening, especially without urgent medical treatment. If it continues, it can raise pressure on the right side of the heart and eventually cause the right ventricle to fail, leading to swollen legs and tummy and a congested liver.

It says pulmonary oedema can only be prevented by preventing its causes. The most common is heart problems, so keeping the heart healthy helps: not smoking, limiting alcohol, a balanced diet, regular exercise, a healthy weight, controlling blood pressure and diabetes, and taking prescribed medicines. If you are going to a high-altitude region, take expert advice before you travel.

Sudden pulmonary oedema is treated as an emergency through 999 and A&E, with admission to hospital. If heart failure is the cause, ongoing care is with a GP and a heart failure specialist team on the NHS.

Private cardiology and respiratory services can arrange echocardiography, blood tests and follow-up for the underlying cause, but acute breathlessness always needs emergency care.