Search Media Items

Breathing involves two phases: breathing in and breathing out. Your lungs deliver oxygen and remove carbon dioxide from your blood in a process called gas exchange. Gas exchange happens in the capillaries surrounding the alveoli, where the oxygen that is breathed in enters the circulatory system and carbon dioxide in the blood is released to the lungs and then breathed out. If you have problems breathing, gas exchange may be impaired, increasing the risk of serious health problems.

You can take steps to help protect your lungs from injury or disease, including quitting smoking and avoiding secondhand smoke, aiming for a healthy weight, being physically active, and limiting exposure to air pollution.

The body’s muscles and nervous system help control your breathing. The lungs are like sponges; they cannot move on their own. Muscles in your chest and abdomen contract, or tighten, to create space in your lungs for air to flow in. The muscles then relax, causing the space in the chest to get smaller and squeeze the air back out. Your breathing usually does not require any thought, because it is controlled by the autonomic nervous system, also called the involuntary nervous system.

The respiratory system helps you breathe. The main parts of the respiratory system are the lungs, the airways, and the muscles that enable breathing. The circulatory system, which is made up of the heart, veins, arteries, and capillaries, brings blood to and from the lungs and delivers nutrients and oxygen to tissues of the body while removing carbon dioxide and waste products. Other body systems that work with the respiratory system include the nervous system, lymph system, and immune system.

Damage to the lung’s air sacs—called alveoli—causes ARDS. Fluid from tiny blood vessels leaks through the damaged walls of the air sacs and collects, limiting the lungs’ normal exchange of oxygen and carbon dioxide. The damage also causes inflammation that leads to the breakdown of surfactant—a liquid that helps keep your air sacs open.

You may have an increased risk of ARDS because of infection, environmental exposures, lifestyle habits, genetics, other medical conditions or procedures, race, or sex. Risk factors can vary depending on your age, overall health, where you live, and the healthcare setting in which you receive care.

Your doctor may screen for ARDS if you have risk factors for ARDS. Getting vaccines to prevent the flu and other infections, avoiding tobacco smoke, limiting the amount of alcohol you drink, and limiting your exposure to pollution can reduce your risk of getting ARDS.

Difficulty breathing is usually the first symptom of ARDS. Other signs and symptoms of ARDS may vary depending on the underlying cause and how severely you are affected. ARDS may take several days to develop, or it can rapidly get worse. Complications may include blood clots, infections, additional lung problems, or organ failure.

Your doctor will diagnose ARDS based on your medical history, a physical exam, and test results. ARDS can be difficult to diagnose and is often mistaken for another condition, so it is important to know your symptoms.

The goal of treatment for ARDS is to improve oxygen levels and treat the underlying cause. Other treatments aim to prevent complications and make you comfortable.