Lungs

Your lungs are a pair of organs that are the main part of your respiratory system, a network of structures and tissues that allow you to breathe. They pull air into your body so your tissues can get oxygen.

You have two lungs, a right and a left. Many people think of them like balloons. But they’re actually made up of spongy tissue, airways (tubes that air travels through), air sacs (alveoli) and blood vessels. The blood vessels pick up oxygen from the air sacs and deliver it to the rest of your body.

What do lungs do?

Your lungs’ main function is to bring oxygen to your blood and remove carbon dioxide from your body. When you inhale through your nose or mouth, air travels down your pharynx (back of your throat), passes through your larynx (voice box) and into your trachea (windpipe). Then, it moves into your left and right bronchial tubes and into smaller and smaller passages (bronchioles).

Your airways end in tiny air sacs called alveoli. These are surrounded by blood vessels. Your alveoli hold the air, and the blood that flows by picks up oxygen. Your blood delivers the oxygen to your tissues to use for energy. At the same time, your blood also drops off carbon dioxide to your lungs, which you breathe out on your next exhale. This process happens 12 to 20 times per minute.

Where are your lungs in your body?

Your lungs are located in your chest (thorax), inside your rib cage. Your thoracic cavity is the space that contains your lungs and other organs of your chest.

Lung structure

Your lungs are made up of spongy, pinkish-gray tissue (connective tissue). They’re thicker in your back and get thinner as they curve around to your chest. They’re shaped a bit like cones or upside-down elephant ears: They have a narrow top part that extends toward your shoulders and a wider bottom.

Your bronchial tubes enter your lungs and branch into smaller and smaller airways until they reach the alveoli. The alveoli look a bit like a bunch of tiny grapes. Your lungs are covered in thin layers of tissue called pleura. These layers reduce friction as your lungs get bigger when they fill and smaller when they empty. Many blood vessels bring blood into and out of your lungs.

You have two lungs, one on each side of your chest. Each lung is divided into sections (lobes). They’re separated by folds called fissures. Your lungs rest on your diaphragm, a muscle that contracts and relaxes to pull air into your lungs.

Right lung

The lung on your right side is divided into three lobes: the superior, the middle and the inferior. It’s shorter and wider than your left lung.

Left lung

Your left lung has two lobes: the superior and the inferior. The superior lobe has an indent (cardiac notch) to make space for your heart. The piece of the superior lobe that curls down around the left and bottom of your heart is called the lingula.

How big are your lungs?

A typical adult lung weighs about 2.2 pounds (1 kilogram) and is a little longer than 9 inches (about 24 centimeters) when you’re breathing normally. It’s about 10.5 inches (27 cm) when your lungs are completely expanded.

What diseases affect your lungs?

Conditions that affect your lungs include:

• Asthma: Inflammation of your airways when you’re exposed to triggers
• Bronchiectasis: Widened airways that can develop pouches
• Bronchitis: Inflammation and mucus in your airways
• COPD (chronic obstructive pulmonary disease): Damage to your airways that blocks your breathing and gets worse over time
• Cystic fibrosis: An inherited condition that causes sticky mucus to build up in your lungs and other organs
• Infections: Flu, COVID-19, RSV, tuberculosis and other germs can infect your lungs and airways
• Interstitial lung disease: Damage and scarring in your lungs, like pulmonary fibrosis and asbestosis
• Lung cancer: Growths in your lungs that can spread to other organs
• Mesothelioma: A type of cancer in the lining of your lungs
• Pneumonia: Inflammation and fluid in your lungs caused by an infection
• Pulmonary nodules: “Spots” on your lungs

Signs and symptoms

Symptoms of lung disease can include:

• Cough
• Chest pain, tightness or discomfort
• Shortness of breath
• Tiredness

These symptoms are common, and many other conditions can cause them. Talk to a healthcare provider if you’re experiencing symptoms that affect your breathing.

How to care for your lungs

To keep your lungs healthy:

• Don’t smoke or vape. It’s never too late to quit.
• If you have to work with materials that create dust or fumes, wear a respirator mask and make sure the area is well-ventilated.
• Maintain a weight that’s healthy for you.
• Get regular physical activity. This helps your heart and lung muscles stay strong.
• Drink plenty of fluids.
• Take steps to avoid respiratory infections. This includes washing your hands frequently and wearing a mask when respiratory illnesses, like the flu and COVID-19, are spreading. Ask a provider which vaccines are recommended for you.