Smoking is by far the most common cause of emphysema, responsible for the vast majority of cases. But it’s not the only one. A genetic condition, workplace exposures, and possibly even vaping can also damage the lungs enough to trigger the disease. Understanding how each cause works helps explain why some people develop emphysema and others don’t.
What Happens Inside the Lungs
Your lungs contain hundreds of millions of tiny air sacs that exchange oxygen and carbon dioxide with your blood. In emphysema, these air sacs are permanently destroyed. They don’t regenerate. As more are lost, the lungs lose surface area for gas exchange, and breathing becomes progressively harder.
The destruction follows a specific pattern. Your lungs normally maintain a balance between enzymes that break down tissue (proteases) and protective proteins that keep those enzymes in check (antiproteases). When something disrupts that balance, enzymes like neutrophil elastase digest the structural proteins holding the air sacs together: elastin, collagen, and fibronectin. Without these scaffolding proteins, the thin walls between air sacs collapse, merging small sacs into larger, less efficient ones. The lung tissue also loses its ability to repair itself, compounding the damage over time.
Smoking: The Leading Cause
Cigarette smoke triggers a self-amplifying cycle of inflammation in the lungs. When smoke particles land on airway surfaces, they activate the immune system’s first-responder receptors. These receptors release chemical signals that pull white blood cells, particularly neutrophils and a specific type of immune cell called monocyte-derived macrophages, out of the bloodstream and into lung tissue. In damaged lungs, these recruited macrophages can make up nearly half of all the immune cells in the air sacs.
Once there, these cells release a cocktail of inflammatory molecules and tissue-destroying enzymes, including several types of metalloproteinases directly linked to the breakdown of the lung’s structural framework. They also release signaling chemicals that recruit even more immune cells, creating a feedback loop. Each cigarette restarts the cycle, and the cumulative effect over years is permanent tissue loss.
The damage from smoking typically concentrates in the upper portions of the lungs first, centered around the smallest airways. This pattern, called centrilobular emphysema, is the signature of smoke-related disease. Symptoms usually don’t appear until mid-life, after decades of accumulated damage have destroyed enough air sacs to noticeably affect breathing.
Alpha-1 Antitrypsin Deficiency
About 1 to 5 percent of people diagnosed with COPD (the broader disease category that includes emphysema) have a genetic condition called alpha-1 antitrypsin deficiency. Alpha-1 antitrypsin is a protein your liver produces and releases into the bloodstream. It travels to the lungs, where its main job is to neutralize neutrophil elastase, the enzyme that would otherwise chew through lung tissue.
In people with this deficiency, mutations cause the protein to fold incorrectly and clump together inside liver cells instead of being secreted into the blood. This has two consequences. First, too little protective protein reaches the lungs, leaving them vulnerable to enzyme damage. Second, the clumped proteins that do escape into lung tissue actually attract more neutrophils and cause them to release their destructive enzymes directly into the surrounding tissue. The result is widespread destruction across the entire air sac, not just near the airways, producing a pattern called panacinar emphysema that tends to affect the lower lungs.
People with this deficiency can develop emphysema at a much younger age than typical smokers, sometimes in their 30s or 40s. Smoking dramatically accelerates the process. Diagnosis requires a blood test measuring the protein level along with genetic testing, since the protein can temporarily rise during infections or other inflammatory conditions, masking the deficiency.
Workplace and Environmental Exposures
You don’t have to smoke to develop emphysema. Long-term exposure to certain dusts, fumes, and chemicals at work can cause the same kind of chronic lung inflammation. The American Lung Association identifies several specific workplace hazards:
- Mineral dusts such as silica, coal, and asbestos
- Metal and welding fumes including cadmium
- Diesel exhaust and vehicle fumes
- Organic dusts from cotton, wood, or grain
- Asphalt, tar fumes, and roofing vapor
- Smoke from fires, relevant for firefighters and agricultural workers
- Secondhand tobacco smoke in enclosed workplaces
These exposures trigger the same protease-antiprotease imbalance that smoking does. Inhaled particles activate immune receptors in the airways, drawing in inflammatory cells that release tissue-destroying enzymes. Workers in mining, construction, welding, agriculture, and manufacturing face the highest risk, particularly when exposure spans years or decades without adequate respiratory protection.
Vaping and E-Cigarettes
A Johns Hopkins Medicine analysis of nearly 250,000 people found that exclusive e-cigarette use (meaning no traditional cigarettes) was significantly associated with developing COPD. Notably, the same study found no significant link between exclusive vaping and heart failure or cardiovascular disease, suggesting something specific about the way e-cigarette aerosol affects lung tissue. Researchers have called these results “a critical stepping stone” but note that longer follow-up is needed to fully understand the risk over decades. For now, the evidence is strong enough to take seriously: vaping is not a risk-free alternative when it comes to your lungs.
Why Some Smokers Never Get It
Not every long-term smoker develops emphysema, which points to individual differences in how the lungs respond to damage. Genetics play a role beyond just the alpha-1 antitrypsin gene. Variations in how aggressively your immune system responds to irritants, how efficiently your body repairs damaged tissue, and how well your natural antiprotease defenses function all influence whether chronic exposure tips over into permanent destruction. Age matters too. The longer the exposure continues, the more cumulative damage builds, and the lung’s repair capacity declines with age.
How Emphysema Is Confirmed
If you’re experiencing persistent shortness of breath, a chronic cough, or reduced exercise tolerance, a breathing test called spirometry is the standard diagnostic tool. You blow as hard and fast as you can into a device that measures two things: the total air your lungs can expel and how much comes out in the first second. When the ratio of that first-second volume to total volume falls below 70 percent, it indicates airflow obstruction consistent with emphysema or other forms of COPD. CT scans can also reveal the characteristic pattern of destroyed air sacs and help distinguish emphysema from other lung conditions.
COPD, the disease category encompassing emphysema, is the fourth leading cause of death worldwide, responsible for 3.5 million deaths in 2021. Nearly 90 percent of those deaths in people under 70 occurred in low- and middle-income countries, where occupational exposures, indoor air pollution from cooking fuels, and limited healthcare access compound the problem.