January 2, 2024/Lung

WARNING: Even Light Smoking Affects Respiratory Health

Even only a couple cigarettes a day can lead to potentially deadly lung diseases like COPD and emphysema

lit cigarette floating in black background

Think there’s no harm in just a cigarette here and there? Think again.


Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

Even light smokers who puff on just a few cigarettes a day run an increased risk of developing potentially deadly chronic lung diseases like emphysema and chronic obstructive pulmonary disease (COPD).

Add those respiratory issues (as well as lung cancer) to the long list of reasons why cigarette smoking ranks as the No. 1 cause of preventable disease, disability and death in the United States and the world.

Let’s take a closer look at how smoking harms your lungs with pulmonologist Humberto Choi, MD — plus steps you can take to reverse the damage. (SPOILER ALERT: A move toward better health involves the word “quit.”)

What is chronic lung disease?

Chronic lung disease isn’t just one single type of respiratory disease. Think of it more as an umbrella term covering an assortment of conditions that prevent your lungs from working the way they should.

Common types of chronic lung disease include:

  • Chronic obstructive pulmonary disease (COPD): Smoking causes about 80% of deaths from COPD, according to the U.S. Centers for Disease Control and Prevention (CDC).
  • Emphysema: This form of COPD damages the walls of your lungs, making it more difficult for you to move air in and out of them.
  • Chronic bronchitis: This condition also is a type of COPD. But in this case, the damage is to tiny hairs (cilia) that work to keep your airways clean.

Chronic lung disease can be traced to many causes, but smoking tops the list. Others include environmental factors (such as air pollution, asbestos and second-hand smoke), infections and even genetics.


Smoking and chronic lung disease

Breathing in chemicals certainly sounds bad for your lungs, right? Well, consider this: Lighting up a cigarette and taking a puff releases thousands of chemicals, many of which carry a toxic designation.

Chemicals in cigarettes can irritate and damage your airways and lungs, says Dr. Choi. Research shows that smoking just a few cigarettes a day can cause immense harm over time.

“It’s a misconception to think that smoking very lightly, just one or two cigarettes a day, could somehow be a safe practice,” states Dr. Choi. “There’s a body of evidence showing that it is not.”

Signs of lung damage from smoking

The cumulative effect of smoking can lead to noticeable changes in your breathing and lung health, including:

  • Shortness of breath. You know that out-of-breath feeling that comes during exercise? Lung damage caused by smoking can make that a regular occurrence even if you’re not exerting yourself.
  • Chronic cough. Coughing is your body’s natural response to try to compensate for gunk that builds up in your airways from smoking.
  • Increased mucus production. Mucus is a defense mechanism your body uses to deal with airway irritants like cigarette smoke. It can also lead to a wet cough often called “smoker’s cough.”
  • Wheezing. Airway inflammation caused by smoking can lead to noisy breathing.

Can you stop chronic lung disease?

If you smoke and are worried about getting chronic lung disease, here’s your best solution: Quit smoking. It’s really that simple. In fact, research shows that heavy smokers who kick the habit have a lower risk of lung disease than current light smokers.

Quitting smoking at any point in life can lower a person’s chance of developing chronic lung disease,” emphasizes Dr. Choi. “It is never too late to quit.”


Within three days of quitting smoking, breathing typically becomes easier. Chronic coughing may ease up after a few months, too, as the cilia (small hairs) in your airways gradually begin to regrow. (Learn more health benefits that come when you stop smoking.)

Talk to a healthcare provider about your options for a smoking cessation program.

Does quitting smoking reverse all damage?

Unfortunately, the answer is no. Years or decades of abusing your lungs can’t just be erased. Some damage will be lasting.

But that doesn’t mean chronic lung disease can’t be managed for better quality of life, says Dr. Choi. Various treatment options can help your lungs. Lifestyle changes, such as quitting smoking, can prevent additional damage and allow for some recovery.

Learn more about our editorial process.

Health Library

Related Articles

Healthcare provider and patient talking in exam room
The Link Between Smoking and Bladder Cancer

Puffing on cigarettes is the leading cause of bladder cancer

person in wheelchair lifting weights in gym
December 26, 2023/Heart Health
7 New Year’s Resolutions To Improve Your Heart Health

Resolve to move a little more, drink a little less, eat a little healthier, sleep a little better and destress a lot

Pregnanct person breaking cigarette
August 29, 2023/Pregnancy & Childbirth
What Happens if You Smoke While Pregnant?

Just a single cigarette a day can have serious health consequences

ash tray with lit cigarette
Can Smoking Cause Diabetes?

Cigarettes increase your risk of developing the condition and worsening its effects

person vaping
July 12, 2023/Lung
Can Vaping Cause Lung Disease?

Vaping isn’t a harmless alternative to smoking

Scissors cutting a lit cigarette.
February 13, 2023/Lung
What Happens to Your Body When You Quit Smoking?

Health benefits start within 20 minutes and continue to grow for years after

A lit candle on a table.
November 21, 2022/Lung
Worried if Candles Are Toxic?

Candles release hydrocarbons into the air, but don’t pose a significant health risk

Closeup of a person smoking an e-cigarette.
October 31, 2022/Lung
Cigarettes, Cigars and Vaping — What’s Worse?

Each comes with substantial health risks and should be avoided

Trending Topics

Person in yellow tshirt and blue jeans relaxing on green couch in living room reading texts on their phone.
Here’s How Many Calories You Naturally Burn in a Day

Your metabolism may torch 1,300 to 2,000 calories daily with no activity

woman snacking on raisins and nuts
52 Foods High In Iron

Pump up your iron intake with foods like tuna, tofu and turkey