Lungs- All You Need To Know About The Lungs

What are Lungs and What is the Function of the Lungs?

The lungs are a pair of spongy, air filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divides into smaller and smaller branches (bronchioles), finally becoming microscopic.

Furthermore, the bronchioles eventually end in clusters of microscopic air sacs called alveoli (any of the many tiny air sacs of the lungs which allow for rapid gaseous exchange). In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled.

Between the alveoli is a thin layer of cells called the interstitium (The interstitium is a lace-like network of tissue that extends throughout both lungs. The interstitium provides support to the lungs' microscopic air sacs (alveoli). Tiny blood vessels travel through the interstitium, allowing gas exchange between blood and the air in the lungs.) This contains blood vessels and cells that help support the alveoli.

The Lungs are covered by a thin tissue layer called the pleura (A thin, transparent membrane that surrounds your lungs, and lines the inside of your ribcage. It has two layers so the outside of the lungs can slide smoothly against the inside of the chest wall as you breathe). The same kind of thin tissue lines the inside of the chest cavity- also called the pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.

To summarise, the lungs absorb oxygen from the air you breathe in and transfer it into your bloodstream so that it can get to every part of your body. As the cells in your body work, they produce a waste gas called carbon dioxide that is released into the bloodstream. Your lungs get rid of this waste gas when you breathe out. Your two lungs fill your chest on either side of your heart. The left lung is smaller than the right lung because it shares that side of the chest with your heart.

The British Lung Foundation quoted that “There are around 300 million air sacs and if they were spread out they would cover an area roughly the size of a tennis court. Every Day you take about 2,500 breaths, mostly without thinking. If you’re resting, an adult with breathe around 12-20 times a minute which adds up to around 17,000-30,000 times per day. The amount of air that moves in and out of your lungs can vary from just a few litres per minute to over 100 litres per minute if exercising vigorously.”

lungs diagram

What are the Main Types of Lung Diseases?

The main types of different lung diseases fall under the umbrella of COPD, which includes Emphysema, Chronic Bronchitis, Pulmonary Embolism, Pneumonia and many amongst others. Smoking increases your risk of developing these lung related diseases. 

What Is COPD?

Chronic Obstructive Pulmonary Disease (COPD) describes a group of lung conditions that make it difficult to empty air out of the lungs because your airways have been narrowed. Chronic means it’s a long term condition that does not go away, Obstructive means your airways are narrowed, so it’s harder to breathe out quickly, Pulmonary means it affects your lungs and Disease means it is a medical condition. With COPD the airways are narrowed because the lung tissue is damaged so there is less pull on the airways, the elastic lining of the airway flops and the airway lining is inflamed.

COPD DiagramCOPD StagesCOPD Symptoms

What are the Symptoms of COPD?

• Shortness of breath easily when doing everyday tasks such as going for a walk or doing housework

• Increased Breathlessness i.e. when exercising or you may wake up at night feeling breathless

• Persistent chesty cough

• Wheezing in cold weather

• Producing more sputum or phlegm than usual

• Frequent chest infections

• Persistent wheezing

See your GP and seek professional medical advice if you are experiencing any of the symptoms listed above and feel you may have COPD.


What is Emphysema?

Emphysema affects the air sacs at the end of the airways in your lungs. They break down and the lungs become baggy and full of holes which trap air. This is a condition in which the air sacs of the lungs are damaged and enlarged causing breathlessness. Emphysema is a type of chronic obstructive pulmonary disease (COPD). It involves the loss of elasticity and enlargement of the air sacs in the lung. The alveoli at the end of the bronchioles of the lung become enlarged because their walls break down or the air sacs are destroyed, narrowed, collapsed, stretched, or over-inflated. Having fewer and larger damaged sacs means there is a reduced surface area for the exchange of oxygen into the blood and carbon dioxide out of it. The damage is permanent. The ability to breathe properly cannot be fully recovered.

emphysema diagram

What are the Symptoms of Emphysema?

• Breathing difficulties

• Wheezing

• Constant cough

• Chest tightness

• Chest pain

See your GP and seek professional medical advice if you are experiencing any of the symptoms listed above and feel you may have Emphysema.

What is Chronic Bronchitis?

Chronic bronchitis is the opposite of emphysema. This condition causes a person’s lungs to become very inflamed. Bronchitis commonly affects the windpipe and passageways of the lungs and is the result of severe irritation or infection. It can be a brief illness, or ongoing (chronic). The body’s natural reaction to chronic bronchitis is to clear the air passages, resulting in severe coughing.

chronic bronchitis diagram

What are the Symptoms of Chronic Bronchitis?


• Production of mucus (sputum) which can be clear, white, yellowish grey or green in colour, rarely it may be streaked with blood

• Fatigue

• Shortness of breath

• Slight fever and chills

• Chest discomfort

See your GP and seek professional medical advice if you are experiencing any of the symptoms above and feel you may have Chronic Bronchitis.

What is the difference between Emphysema and Chronic Bronchitis?

Emphysema gradually narrows the air sacks and destroys the alveoli; however chronic bronchitis is dualistic of this function as it causes the wind pipe and passage weighs of the lungs to become inflamed.

What is Pulmonary Embolism?

Pulmonary Embolism is the sudden blockage of major blood vessel (artery) in the lung, usually by a blood clot. These clots can damage the lungs as it stops blood flow to the lung and it can be deadly.

pulmonary embolism diagram

What are the Symptoms of Pulmonary Embolism?

• Sudden shortness of breath

• Sharp chest pain that is worse when you cough or take a deep breath

• A cough that brings up pink, foamy mucus

• Coughing up blood

See your GP and seek professional medical advice if you are experiencing any of the symptoms above and feel you may have Pulmonary Embolism.

What is Pneumonia?

Pneumonia is a type of chest infection. It affects the tiny air sacs in your lungs, called alveoli. When you have pneumonia the air sacs become inflamed and filled with fluid. This makes it harder for you to breathe.

pneumonia diagram

What are the Symptoms of Pneumonia?

• Chest pain when you breathe or cough

• Cough which may produce phlegm

• Fatigue

• Fever, sweating and shaking chills

• Nausea

• Vomiting

• Diarrhoea

• Shortness of breath

See your GP and seek professional medical advice if you are experiencing any of the symptoms above and feel you may have Pneumonia.

Read our Smokers Cough Advice

What are the Risk Factors Lung Disease?

• The destructive effect on a smoker's lungs will vary depending on the volume of cigarettes smoked and how long the person has been smoking for

• Smoking

• Exposure to certain chemicals

• Air Pollution

• Genetics

• Second Hand Smoke

• If the underlying route cause for example smoking is continued by the person then the risk of developing lung cancer is more likely

lung disease risk factors

How do you keep your Lungs Healthy?

• Stop Smoking


• Avoid Exposure to Pollutants

• Healthy balanced diet would also help improve lung function. 


The British Lung Foundation is the number one recognised charitable organisation in the UK for Lung support.