Emphysema is a form of chronic obstructive pulmonary disease, or COPD, in which the lungs’ tiny air sacs, called alveoli, are damaged and destroyed, trapping air and making it hard to breathe out fully. It usually develops slowly, often after decades of exposure to cigarette smoke or other lung irritants, and the shortness of breath it causes can build so gradually that people adjust their activities long before they notice how much breathing capacity they have lost. The damage itself cannot be undone, but emphysema is not untreatable: quitting smoking and the right ongoing care can slow its progress and ease daily symptoms. This guide explains what emphysema is, its symptoms, causes, how it is diagnosed, the treatments available, and the latest research.
What is emphysema?
Emphysema is a lung disease in which the walls of the alveoli, the tiny air sacs where oxygen passes into the blood, are damaged and gradually destroyed. As these delicate walls break down, the lungs lose the elastic recoil that normally helps push air back out, so air becomes trapped with each breath and less fresh air moves in and out. Over time, the lungs’ surface area for exchanging oxygen and carbon dioxide shrinks, which is what produces the persistent shortness of breath at the center of this disease.
Emphysema is one of the two main forms of chronic obstructive pulmonary disease, the other being chronic bronchitis, and many people have overlapping features of both. Recognizing the airflow limitation that defines COPD and the mucus-driven cough of chronic bronchitis helps explain why emphysema is rarely a diagnosis on its own. More than 3 million Americans live with emphysema specifically, while COPD overall, which includes both emphysema and chronic bronchitis, affects over 14 million US adults and ranks among the leading causes of death in the country.
Symptoms of emphysema
The hallmark symptom of emphysema is shortness of breath that develops gradually and worsens over months and years, often first noticed during physical activity such as climbing stairs or walking briskly. Other common symptoms include a chronic cough, wheezing, tightness in the chest, and persistent fatigue. Because these changes build up slowly, many people scale back their activities without fully realizing how much their breathing has changed.
As emphysema advances, unintended weight loss becomes common, partly because breathing itself takes more energy, and some people develop a barrel-shaped chest as the lungs become chronically overinflated. People with more advanced disease also experience flare-ups, or exacerbations, in which symptoms suddenly worsen, often triggered by a respiratory infection, and these episodes can temporarily or permanently reduce lung function if they are not treated promptly.
What causes emphysema and its risk factors
Cigarette smoking is by far the leading cause of emphysema in the United States, and roughly three in four people with COPD have a history of smoking. Risk rises with how many years and how much a person has smoked, though the effects of that exposure often do not produce noticeable symptoms until later in life. Secondhand smoke, long-term exposure to indoor and outdoor air pollution, and occupational exposure to dust, chemical fumes, and vapors are other established risk factors, particularly for people who also smoke.
A smaller share of emphysema cases stem from alpha-1 antitrypsin deficiency, an inherited disorder that leaves the lungs without enough of a protein that normally protects them from damage, which can lead to emphysema at a younger age, sometimes in people who have never smoked. Some people also have overlapping features of emphysema and asthma, a pattern sometimes called asthma-COPD overlap, which is one reason doctors ask about wheezing and allergy history alongside smoking history; reviewing the airway-narrowing pattern of asthma can help clarify which condition, or combination of conditions, best explains a person’s symptoms.
How emphysema is diagnosed
Emphysema is diagnosed with a breathing test called spirometry, which measures how much air you can forcefully exhale and how quickly. A post-bronchodilator FEV1/FVC ratio below 0.70 confirms persistent airflow obstruction and supports a diagnosis of COPD. A chest CT scan is more sensitive than a standard chest X-ray for visualizing the destroyed air sacs that define emphysema, and either imaging test can also help rule out other conditions, such as lung cancer or infection. Once airflow obstruction is confirmed, doctors often grade its severity using the GOLD staging system, shown below.
| GOLD stage | Airflow obstruction on spirometry |
|---|---|
| GOLD 1 (mild) | FEV1 at or above 80% of the predicted value |
| GOLD 2 (moderate) | FEV1 between 50% and 79% of the predicted value |
| GOLD 3 (severe) | FEV1 between 30% and 49% of the predicted value |
| GOLD 4 (very severe) | FEV1 below 30% of the predicted value |
Blood tests add important context. Because alpha-1 antitrypsin deficiency is an inherited cause of emphysema that can affect nonsmokers and younger adults, every person diagnosed with COPD or emphysema should have a one-time alpha-1 antitrypsin test; checking the alpha-1 globulin fraction on a blood protein test can offer an early clue that prompts this specific testing and, if positive, screening of family members. A blood eosinophil count helps predict who is likely to benefit from adding an inhaled corticosteroid or, in selected cases, a newer biologic medicine to reduce flare-ups, and following the eosinophil count on a complete blood count over time shows why this single number can shape treatment choices. Arterial blood gas testing measures the oxygen and carbon dioxide in the blood and helps determine whether supplemental oxygen is needed. Because chronically low blood oxygen can push the body to make extra red blood cells, tracking the hemoglobin level and the hematocrit percentage over time can reveal this compensation. Learning how to read the flags and reference ranges on a lab report can help you follow these results between visits.
Treatment options for emphysema
Emphysema cannot be reversed: once alveoli are destroyed, the lungs cannot regrow them. But treatment can ease symptoms, reduce flare-ups, and slow the pace of further decline, and the single most effective step at any disease stage is quitting smoking completely. For people who need help quitting, combining counseling with nicotine replacement or a prescription medication substantially improves the odds of success.
| Approach | Role |
|---|---|
| Long-acting bronchodilators (LAMA/LABA) | Relax the airway muscles and serve as the first-line inhaled therapy for ongoing symptom control |
| Inhaled corticosteroids | Added for selected patients with frequent flare-ups or a higher blood eosinophil count |
| Pulmonary rehabilitation | A supervised program of exercise, education, and breathing techniques that builds stamina and confidence |
| Supplemental oxygen | Prescribed when blood oxygen levels are low, to protect the heart and other organs |
| Vaccines | Annual flu and COVID-19 vaccines plus pneumococcal vaccination reduce infections that can trigger flare-ups |
| Endobronchial valves, lung volume reduction surgery, or transplant | Considered for carefully selected patients with advanced disease to improve breathing and quality of life |
Flare-ups, also called exacerbations, are treated with short-acting bronchodilators plus a short course of oral corticosteroids, and antibiotics when a bacterial infection is suspected; severe flare-ups can require hospitalization. Because these episodes can cause lasting drops in lung function, preventing them through vaccination, steady medication use, and prompt treatment is a central goal of long-term care.
Living with emphysema and long-term outlook
Damage to the alveoli from emphysema is permanent, but this diagnosis is not a sentence to inevitable decline: with the right treatment plan, many people slow the disease significantly and remain active for years. The single most important action anyone with emphysema can take is to quit smoking and avoid secondhand smoke, since continued exposure accelerates lung damage regardless of what other treatments are used. Staying current with pulmonary rehabilitation, prescribed inhalers, and vaccinations, and building strength through regular activity within one’s own limits, all support day-to-day breathing and independence.
Because emphysema can affect appetite and energy, unintended weight loss is common in more advanced disease, and getting enough calories and protein helps preserve muscle strength, including the muscles used for breathing. Regular follow-up allows a care team to catch and treat flare-ups early, adjust oxygen or medication needs, and watch for related conditions. Many people also benefit from a pulmonary rehabilitation program or a support group, since living well with a chronic lung disease often depends as much on daily habits and support as it does on medication.
Latest scientific advances in emphysema research
Recent research has expanded the drug options for people whose emphysema symptoms persist despite standard inhalers. According to PubMed-indexed research, a pooled analysis of the BOREAS and NOTUS trials, which led to the first FDA-approved biologic medicine for COPD, found that adding dupilumab in patients with type 2 inflammation improved a combined measure of death, hospitalization, flare-ups, lung function, and quality of life by 31 percent compared with placebo (Ramakrishnan et al., 2026). What this means for you: for people whose blood eosinophil counts point to type 2 inflammation and who keep having flare-ups on inhaled therapy, a biologic medicine is now a realistic option to discuss with a specialist, not just a change in inhalers. Separately, a phase 3 trial of ensifentrine, an inhaled medicine that works differently from existing bronchodilators, confirmed meaningful improvements in lung function and day-to-day breathlessness when added to standard treatment, regardless of COPD severity (Zhou et al., 2026). What this means for you: ensifentrine offers a steroid-free add-on option for people who still feel short of breath even while using their regular inhalers.
Other research has clarified the safety of a procedure used in advanced emphysema. A meta-analysis of randomized trials of endobronchial valves, small one-way devices placed in the airway to help deflate the most damaged parts of the lung, found that the added risk of death with this procedure is concentrated in the first 90 days, driven mainly by a collapsed lung, and does not continue beyond that window (Mari et al., 2026). What this means for you: for patients considering endobronchial valves for severe, hyperinflated emphysema, the procedure carries a real but time-limited risk that is manageable with close monitoring in the weeks afterward, rather than an ongoing survival disadvantage. Together, these studies show that care for advanced emphysema is becoming more precise, matching newer medicines and procedures to the patients most likely to benefit from each.
Glossary of key emphysema terms
| Term | Definition |
|---|---|
| Alveoli | Tiny air sacs in the lungs where oxygen and carbon dioxide are exchanged with the blood. |
| Spirometry | A breathing test that measures how much and how quickly air moves in and out of the lungs. |
| FEV1/FVC ratio | The share of total exhaled air pushed out in the first second of a forceful breath, used to detect airflow obstruction. |
| GOLD stage | A 1-to-4 classification of COPD severity based on the degree of airflow obstruction on spirometry. |
| Alpha-1 antitrypsin deficiency | An inherited condition that lowers a protective lung protein and can cause emphysema at a younger age. |
| Pulmonary rehabilitation | A supervised program combining exercise, education, and breathing techniques for people with chronic lung disease. |
| Exacerbation | A flare-up of emphysema symptoms, often triggered by infection, that temporarily worsens breathing. |
Frequently asked questions about emphysema
What is emphysema and how is it different from COPD overall?
Emphysema is a lung disease in which the walls of the tiny air sacs, or alveoli, are damaged and destroyed, so the lungs lose their elastic recoil and trap air, making it hard to fully exhale. It is one of the two main forms of chronic obstructive pulmonary disease, or COPD, the other being chronic bronchitis, and many people with COPD have features of both. COPD is the broader umbrella term, while emphysema describes this specific pattern of air-sac damage.
What are the earliest signs and symptoms of emphysema?
The earliest and most common symptom is shortness of breath that develops gradually over years, often first noticed during exercise or exertion rather than at rest. Other early symptoms include a chronic cough, wheezing, chest tightness, and fatigue. Because these signs build up slowly, many people adjust their activity level without realizing how much lung function they have lost.
What causes emphysema besides cigarette smoking?
Secondhand smoke, long-term exposure to indoor and outdoor air pollution, and workplace exposure to dust, chemical fumes, and vapors can all damage the alveoli over time, particularly alongside a smoking history. A smaller number of cases are caused by alpha-1 antitrypsin deficiency, an inherited condition that can lead to emphysema at a younger age, including in people who have never smoked.
What are the stages of emphysema (GOLD 1-4) and what do they mean?
Once spirometry confirms airflow obstruction, doctors often grade its severity using the GOLD system, from stage 1, which is mild, through stage 4, which is very severe, based on how much air can be forcefully exhaled compared with a predicted normal value. Staging helps guide treatment intensity and gives a general sense of how advanced the disease is, though day-to-day symptoms do not always track perfectly with the numerical stage.
Can emphysema be reversed, or only slowed?
The alveolar damage caused by emphysema is permanent and cannot be reversed or regrown. Treatment, especially quitting smoking, can substantially slow further decline, ease symptoms, and reduce flare-ups, which is why an emphysema diagnosis does not mean a rapid or inevitable decline for most people.
What blood tests help diagnose or monitor emphysema?
Every person diagnosed with COPD or emphysema should have a one-time alpha-1 antitrypsin test to check for an inherited cause, particularly if they are younger or have little smoking history. A blood eosinophil count helps guide whether an inhaled corticosteroid or biologic medicine might reduce flare-ups, arterial blood gas testing checks oxygen and carbon dioxide levels, and hemoglobin and hematocrit are watched because chronically low blood oxygen can raise red blood cell counts over time.
Sources
- Cleveland Clinic — Emphysema — Cleveland Clinic Health Library, 2023 — my.clevelandclinic.org
- Mayo Clinic — Emphysema – Diagnosis and treatment — Mayo Clinic, 2024 — mayoclinic.org
- MedlinePlus, National Library of Medicine — Alpha-1 Antitrypsin Testing — MedlinePlus, 2024 — medlineplus.gov
- Ramakrishnan et al. — Win Ratio Analysis to Clarify Clinical Benefits: A Post Hoc Analysis of Phase 3 BOREAS and NOTUS (Two Pivotal Studies to Assess the Efficacy, Safety, and Tolerability of Dupilumab in Patients With Moderate-to-Severe COPD With Type 2 Inflammation) — Chest, 2026 — doi.org/10.1016/j.chest.2026.02.005
- Zhou et al. — Efficacy and Safety of Ensifentrine in Chinese Participants With COPD: The ENHANCE-CHINA Randomized Clinical Trial — Chest, 2026 — doi.org/10.1016/j.chest.2026.02.035
- Mari et al. — Peri-procedural vs. post-procedural mortality after endobronchial valve treatment for severe emphysema: a systematic review and meta-analysis of randomized controlled trials — Expert Review of Medical Devices, 2026 — doi.org/10.1080/17434440.2026.2710806
Further reading
- See why smoking’s damage extends beyond the lungs’ air sacs in this guide to the symptoms and causes of lung cancer.
- Understand a common trigger for emphysema flare-ups in this guide to the symptoms and treatment of pneumonia.
Understand your lab results with BloodSense
Emphysema care depends on more than a single breathing test: a one-time alpha-1 antitrypsin check, a blood eosinophil count, arterial blood gas results, and hemoglobin and hematocrit levels all help your care team fine-tune treatment and catch complications early. Seeing where each of these values falls against its reference range, and how they shift from one visit to the next, makes them far easier to understand and to discuss with your care team. BloodSense translates a full lab report into plain, clear language, showing what each marker means on its own and alongside your other results, instead of leaving you to interpret a page of numbers alone.
