Acute Respiratory Distress Syndrome

Overview

Acute Respiratory Distress Syndrome, often called ARDS, is a serious lung condition in which the lungs become severely inflamed and filled with fluid. This makes it difficult for oxygen to pass from the lungs into the bloodstream, so the body’s organs may not receive enough oxygen to work properly.

ARDS usually develops quickly, often within hours or days after a major illness, infection, injury, or other serious medical event. It is not a single disease by itself, but a complication of another condition affecting the body. ARDS requires urgent medical care, usually in a hospital setting and often in an intensive care unit.

Although ARDS can be life-threatening, many people improve with timely supportive care and treatment of the underlying cause. Recovery may take time, and some patients need rehabilitation and follow-up care after leaving the hospital.

Symptoms

The symptoms of ARDS can appear suddenly and may worsen rapidly. The main problem is severe difficulty breathing due to low oxygen levels.

• Shortness of breath that becomes severe or does not improve
• Fast or labored breathing
• Feeling unable to get enough air
• Extreme tiredness or weakness
• Confusion, restlessness, or drowsiness due to low oxygen levels
• Bluish color of the lips, fingertips, or skin in severe cases
• Chest discomfort or a feeling of tightness
• Rapid heartbeat

Symptoms often occur in people who are already unwell, such as those with severe infection, trauma, or complications after major surgery. Because ARDS can progress quickly, breathing changes in a seriously ill person should always be treated as urgent.

Causes and Risk Factors

ARDS occurs when inflammation damages the tiny air sacs in the lungs. Fluid then leaks into these air sacs, reducing the amount of oxygen that can enter the bloodstream. The trigger may begin in the lungs or elsewhere in the body.

Common causes and risk factors include:

• Severe infections affecting the lungs or bloodstream
• Pneumonia or serious viral respiratory infections
• Inhalation of smoke, chemicals, or harmful substances
• Major trauma, burns, or shock
• Near-drowning or aspiration of stomach contents into the lungs
• Complications after major surgery or serious illness
• Inflammation affecting the whole body
• Multiple blood transfusions or severe reactions in hospitalized patients

Some people may be more vulnerable if they have existing lung disease, a weakened immune system, heavy alcohol use, or other serious medical conditions. However, ARDS can also occur in people who were previously healthy if the triggering illness or injury is severe.

Diagnosis

ARDS is diagnosed by healthcare professionals based on symptoms, physical examination, oxygen levels, imaging tests, and the overall medical situation. Because several conditions can cause breathing failure, doctors also look for other possible explanations, such as heart-related fluid in the lungs.

Evaluation may include:

• Measurement of oxygen levels in the blood
• Chest imaging to look for fluid and inflammation in the lungs
• Blood tests to assess infection, organ function, and oxygen levels
• Heart evaluation when needed to help rule out heart-related causes
• Tests to identify the underlying cause, such as infection or injury

Diagnosis often takes place in an emergency or intensive care setting because patients may need immediate oxygen support while tests are being performed.

Treatment Options

Treatment for ARDS focuses on supporting breathing, improving oxygen delivery, and treating the underlying cause. Care is tailored to the patient’s condition, the severity of breathing failure, and any other organ problems.

Possible treatment approaches include:

• Oxygen therapy to increase oxygen levels in the body
• Breathing support with non-invasive or invasive ventilation when needed
• Careful management of fluids to reduce strain on the lungs while supporting circulation
• Treatment of the underlying cause, such as infection, injury, or inflammation
• Monitoring and support for other organs, including the heart, kidneys, and brain
• Nutritional support during critical illness
• Prevention and management of complications related to intensive care
• Rehabilitation after the acute phase to rebuild strength and lung function

Some patients require mechanical ventilation, which means a machine helps move air in and out of the lungs while the lungs recover. The medical team closely monitors oxygen levels, breathing pressures, and overall stability. Treatment decisions are adjusted continuously according to the patient’s response.

Recovery can vary. Some people improve gradually over days or weeks, while others may need longer hospital care. After recovery from the acute illness, patients may experience fatigue, muscle weakness, shortness of breath, or emotional stress. Follow-up with healthcare professionals can help manage these ongoing needs.

When to See a Doctor

ARDS is a medical emergency. Seek urgent medical attention if a person has severe shortness of breath, rapid breathing, confusion, bluish lips or fingertips, or breathing difficulty that is worsening.

Immediate care is especially important if these symptoms occur after a serious infection, pneumonia, injury, surgery, near-drowning, inhalation injury, or hospitalization for a severe illness. People already in hospital should inform medical staff right away if breathing becomes more difficult or if they feel suddenly worse.

For international patients or families, it is important to share details about recent illnesses, injuries, surgeries, travel, exposures, and existing medical conditions with the healthcare team. Early assessment and supportive care can help doctors identify the cause and provide appropriate treatment as quickly as possible.