Pulmonology

Every breath you take happens automatically — but for millions of people around the world, breathing is something they have to think about.

Pulmonologists are the specialists who diagnose and treat conditions that affect how we breathe, from a persistent cough to complex lung diseases that require ongoing care.

What Is Pulmonology?

Pulmonology — sometimes called respiratory medicine or chest medicine — is a medical specialty focused on the diagnosis, treatment, and management of diseases affecting the respiratory tract. This includes the lungs themselves, the bronchial tubes (airways that carry air into and out of the lungs), the trachea (windpipe), the pleura (the thin lining around the lungs), and the muscles involved in breathing, such as the diaphragm.

A physician who specializes in pulmonology is called a pulmonologist. After completing medical school, pulmonologists undergo years of additional training — typically a residency in internal medicine, followed by a fellowship specifically in pulmonary medicine. Many also train in critical care medicine, since respiratory failure is one of the most common reasons patients end up in the intensive care unit (ICU).

Pulmonology overlaps with several other specialties. It works closely with cardiology (since the heart and lungs are intimately connected), oncology (for lung cancer), immunology (for conditions like hypersensitivity pneumonitis), and infectious disease (for respiratory infections). In many hospitals, pulmonologists also serve as intensivists — critical care doctors who manage patients on ventilators or with life-threatening illnesses.

What Does a Pulmonologist Do?

A pulmonologist evaluates patients who are experiencing symptoms related to breathing and lung function. These may include:

• Chronic or unexplained cough
• Shortness of breath, especially with exertion
• Wheezing or noisy breathing
• Chest tightness or pain related to breathing
• Coughing up blood (hemoptysis)
• Repeated respiratory infections
• Abnormal findings on a chest X-ray or CT scan
• Low oxygen levels in the blood

To understand what is happening in the lungs, pulmonologists use a range of diagnostic tools.

• Pulmonary function tests (PFTs) measure how well the lungs move air in and out — this is one of the most fundamental tests in pulmonology.
• Bronchoscopy allows a pulmonologist to look directly inside the airways using a thin, flexible camera.
• Imaging studies like chest CT scans, high-resolution CT, and PET scans help visualize the lung tissue in detail.
• For some conditions, a lung biopsy may be needed to examine a sample of tissue under the microscope.

The Respiratory System at a Glance

To understand what pulmonologists treat, it helps to know a little about the system they work with. The respiratory system’s main job is gas exchange: bringing oxygen from the air into the bloodstream and expelling carbon dioxide out of the body.

When you inhale, air travels through the nose or mouth, down the trachea, and into the bronchi — the two main branches that lead into each lung. The bronchi divide into smaller and smaller tubes called bronchioles, which eventually end in tiny air sacs called alveoli. The alveoli are surrounded by tiny blood vessels; this is where oxygen passes into the blood and carbon dioxide is removed.

Any disease that disrupts this pathway — whether by narrowing the airways, damaging the alveoli, or stiffening the lung tissue — can make breathing harder and reduce the body’s ability to get the oxygen it needs.

Conditions Treated in Pulmonology

Pulmonology covers a wide spectrum of diseases. Some are very common, affecting hundreds of millions of people worldwide. Others are rare, requiring highly specialized expertise. Here is a look at the major categories.

Asthma

Asthma is one of the most prevalent chronic lung conditions in the world, affecting people of all ages. It involves inflammation and intermittent narrowing of the airways, which causes episodes of wheezing, chest tightness, coughing, and shortness of breath. These episodes — sometimes called asthma attacks or flares — can be triggered by allergens like pollen or pet dander, exercise, cold air, respiratory infections, air pollution, or stress.

Asthma is generally manageable with the right treatment plan, which often includes inhaled corticosteroids to reduce inflammation and bronchodilators to open up the airways during an episode. For people with severe or difficult-to-control asthma, newer biological therapies that target specific immune pathways have been a major advance. While asthma cannot be cured, many people with the condition live full, active lives.

Chronic Obstructive Pulmonary Disease (COPD)

COPD is a progressive disease that makes it increasingly difficult to breathe. It is most commonly caused by long-term exposure to cigarette smoke, though occupational dust and chemical fumes, indoor air pollution, and genetic factors (such as alpha-1 antitrypsin deficiency) can also be responsible.

COPD means two main conditions:

• chronic bronchitis, where the airways are persistently inflamed and produce excess mucus
• emphysema, where the walls of the alveoli are destroyed, reducing the surface area available for gas exchange.

COPD is a leading cause of disability and death globally. Symptoms include a persistent cough (often called a “smoker’s cough”), increased mucus production, and progressive breathlessness.

Treatment focuses on slowing the disease’s progression, managing symptoms, and preventing flares. Bronchodilators, inhaled steroids, pulmonary rehabilitation programs, and, in advanced cases, supplemental oxygen or lung surgery are all part of the management toolkit.

Pneumonia and Respiratory Infections

Pneumonia is an infection that inflames the air sacs in one or both lungs, which may fill with fluid or pus. It can be caused by bacteria (most commonly Streptococcus pneumoniae), viruses (including influenza and SARS-CoV-2), fungi, or other organisms. Symptoms typically include cough, fever, chills, and difficulty breathing.

Many cases resolve with antibiotics or antiviral medications, but pneumonia can be severe or life-threatening, particularly in older adults, young children, and people with weakened immune systems or underlying lung disease.

Other respiratory infections commonly managed by pulmonologists include:

• bronchitis
• bronchiectasis (a condition where the airways are permanently damaged and widened, making them prone to recurring infections)
• tuberculosis (TB), a bacterial infection that primarily affects the lungs and remains one of the world’s leading infectious disease killers.

Lung Cancer

Lung cancer is the leading cause of cancer death worldwide for both men and women. Pulmonologists are often the first specialists involved in evaluating a suspicious lung nodule or mass found on imaging.

They perform bronchoscopies and biopsies to obtain tissue for diagnosis, and they work as part of a multidisciplinary team alongside thoracic surgeons, radiation oncologists, and medical oncologists to plan treatment.

The two main types are:

• non-small cell lung cancer (NSCLC), which accounts for the majority of cases,
• small cell lung cancer (SCLC).

Survival rates have improved significantly in recent years thanks to targeted therapies, immunotherapy, and improved screening protocols. Low-dose CT screening is now recommended for high-risk individuals — particularly long-term heavy smokers — as it can detect lung cancer at an earlier, more treatable stage.

Interstitial Lung Diseases (ILD)

Interstitial lung diseases are a large group of conditions that cause scarring (fibrosis) or inflammation in the interstitium — the tissue and space surrounding the alveoli. This scarring stiffens the lungs, making it harder to breathe and reducing the ability to transfer oxygen into the blood.

The umbrella of ILD includes:

• idiopathic pulmonary fibrosis (IPF)
• hypersensitivity pneumonitis (caused by inhaling certain organic dusts or chemicals)
• sarcoidosis
• lung involvement from autoimmune diseases like rheumatoid arthritis or lupus.

Sleep-Disordered Breathing

Many pulmonologists also specialize in sleep medicine, since breathing problems during sleep are closely tied to lung and respiratory health. Obstructive sleep apnea (OSA) is by far the most common sleep-disordered breathing condition. It occurs when the muscles at the back of the throat relax during sleep, causing the upper airway to partially or completely collapse and temporarily stop breathing.

This can happen dozens or even hundreds of times per night, fragmenting sleep and reducing oxygen levels.

OSA is associated with an increased risk of high blood pressure, heart disease, stroke, and type 2 diabetes.

Pulmonary Hypertension

Pulmonary hypertension (PH) is a type of high blood pressure that affects the arteries in the lungs and the right side of the heart. When the blood vessels in the lungs become narrowed, blocked, or destroyed, it becomes harder for blood to flow through them, raising the pressure and forcing the right ventricle to work harder. Over time, this can weaken the heart.

Pulmonary arterial hypertension (PAH) is a particularly serious form that can occur on its own or in association with connective tissue diseases, HIV, liver disease, or congenital heart defects.

Symptoms — including breathlessness, fatigue, dizziness, and swelling in the ankles and legs — are often mistaken for other conditions, which can delay diagnosis. Specialized medications can slow the disease’s progression, and lung transplantation is an option for some patients.

Occupational and Environmental Lung Diseases

The air we breathe at work and in our environment can have a profound effect on our lung health. Occupational lung diseases are caused by inhaling harmful substances in the workplace — including dusts, fumes, gases, and vapors.

Silicosis (from silica dust), asbestosis (from asbestos fibers), coal workers’ pneumoconiosis (black lung disease), and occupational asthma are all well-recognized examples. These conditions disproportionately affect workers in mining, construction, manufacturing, agriculture, and other industries.

Pulmonary Embolism

A pulmonary embolism (PE) occurs when one or more blood clots travel to the lungs and block the pulmonary arteries. This can cut off blood flow to part of the lung, causing sudden shortness of breath, chest pain, and, in severe cases, life-threatening cardiovascular collapse. PEs most commonly originate as deep vein thrombosis (DVT) — blood clots that form in the deep veins of the legs or pelvis.

Pleural Diseases

The pleura is the two-layered membrane that surrounds each lung and lines the chest cavity. Pulmonologists manage several conditions affecting the pleura.

A pleural effusion is a buildup of fluid in the pleural space, which can result from heart failure, infection, cancer, or inflammatory diseases. A pneumothorax is a collapsed lung, caused by air entering the pleural space. Pleuritis (pleurisy) is inflammation of the pleura, which can cause sharp chest pain that worsens with breathing.

Cystic Fibrosis

Cystic fibrosis (CF) is a genetic disorder that causes thick, sticky mucus to build up in the lungs, digestive tract, and other organs. In the lungs, this mucus traps bacteria and makes patients highly susceptible to recurring infections and progressive lung damage. CF is diagnosed in childhood and was historically a life-limiting condition.

However, the development of CFTR modulator therapies — drugs that target the underlying genetic defect — has transformed outcomes for many patients, dramatically improving lung function and life expectancy.

When Should You See a Pulmonologist?

You may be referred to a pulmonologist by your primary care doctor if you have symptoms that are not responding to standard treatment, if a chest X-ray or scan reveals something that needs further investigation, or if you have been diagnosed with a complex or chronic lung condition that requires specialist management.

You do not need to wait until things are serious. If you are experiencing breathing problems that are affecting your daily life — even if they seem “minor” or you have just chalked them up to getting older or being out of shape — it is worth talking to a doctor.