Lung Day (Hai no Hi)

What Is Lung Day?

Every year on August 1st, Japan observes "Lung Day." It was established in 1999 by the Japanese Respiratory Society to raise awareness of lung health and to encourage the prevention and early detection of respiratory diseases. The date comes from a wordplay (goroawase): 8 and 1 read as "ha-i," sounding like the Japanese word for lung ("hai"). It's a day to learn a little more about the lungs, which work without rest.

Lung Day and Raising Awareness of Respiratory Disease

Around Lung Day, public lectures and awareness activities about respiratory diseases are held.

• COPD (Chronic Obstructive Pulmonary Disease): A disease in which long-term inhalation of cigarette smoke, in particular, causes inflammation in the lungs and gradually worsening breathlessness. Many people are thought to have it without realizing, so quitting smoking and seeing a doctor early are strongly encouraged.
• Lung function testing (spirometry): A test that measures how much air you can breathe out and how fast. The results can also be used to estimate your "lung age," a helpful way to learn about the condition of your lungs.

How Gas Exchange Works

The lungs take oxygen from the air into the blood and release carbon dioxide produced in the body — a process called gas exchange.

• The large surface area of the alveoli: The lungs contain several hundred million tiny sacs called alveoli. Spread out, they are said to cover about 70 to 100 square meters in an adult, allowing efficient gas exchange.
• Gas exchange through diffusion: The membrane between the alveoli and the capillaries is extremely thin, and oxygen and carbon dioxide move across it by diffusion — from areas of higher concentration to lower concentration.

Fascinating Facts About the Lungs

• The lungs can't move on their own: The lungs have no muscles of their own for expanding and contracting. When the diaphragm and the intercostal muscles move, the pressure inside the chest changes and the lungs passively expand and contract.
• How often we breathe: At rest, adults breathe a little over ten times a minute — roughly 20,000 times a day.
• The right and left lungs have different shapes: The right lung has three lobes and the left lung has two. Because the heart sits on the left side, the left lung is slightly smaller.
• Breathing you can adjust: Breathing usually happens automatically, but you can also change its depth and pace to some extent at will.
• Lung function changes with age: Lung function generally peaks around your twenties and then gradually declines. Smoking is one of the major factors that speed up this decline.

Tips for Spending Lung Day

• Think about how you've been feeling, such as how out of breath you get on the stairs. If symptoms persist, consult a doctor.
• If you smoke, look into ways to quit, such as smoking-cessation clinics.
• Review how well your rooms are ventilated.
• Build a habit of moderate exercise such as walking.

A Day to Pay Attention to Your Hard-Working Lungs

August 1st is a day to turn your attention to your lungs, which keep working even while you sleep. If you have concerns such as a long-lasting cough or breathlessness, it's important to see a doctor early. Today, take a breather and spend a moment checking in on your breathing and your health.