COPD isn’t usually hereditary; it’s caused by exposure to pollutants like cigarette smoke. But some people do inherit a protein deficiency that increases their risk of COPD.

A hacking cough and trouble breathing are signs that your lungs aren’t working as well as they should be. These are signs of chronic obstructive pulmonary disease (COPD).

COPD is a group of related lung diseases. The two most common are emphysema and chronic bronchitis. Emphysema is damage to the air sacs in the lungs. Chronic bronchitis is swelling and extra mucus in the airways

About 30 million Americans have COPD, and most have both emphysema and chronic bronchitis.

Most of the time COPD isn’t hereditary. It’s usually caused by things you’re exposed to, such as tobacco smoke or chemical fumes.

Yet sometimes genes do play a role in the disease. People with the inherited condition alpha-1 antitrypsin deficiency (AATD) are born with the improper code to make the protein called alpha-1 antitrypsin. This can result in not having enough alpha-1 antitrypsin protein or having defective proteins.

This protein normally protects the body against the enzyme neutrophil elastase. Without enough alpha-1 antitrypsin, neutrophil elastase attacks the body’s tissues—especially the lungs. The liver can also be damaged when the defective proteins clog it up. Exposure to tobacco smoke or chemicals can make AATD worse.

About 1 out of every 1,500 to 3,500 people has AATD. It’s more common in people whose families are of European descent. You have to inherit two copies of a faulty gene, one from each of your parents, to get the disease. If you inherit only one copy of the gene, you’ll be a carrier. This means you won’t have the disease, but you can pass the gene to your children.

If you have AATD, you can protect your lungs by not smoking. You should also avoid chemical fumes and dust. The more inflammation you have in your lungs, the more neutrophil elastase is produced. The more neutrophil elastase, the more damage you’ll have. Your doctor may give you the AAT protein as a replacement shot to increase your protein levels and help treat the disease.

Smoking isn’t just a risk factor for COPD—it’s the biggest risk for this disease. The chemicals in cigarettes and other types of tobacco smoke irritate and damage the lungs. Breathing in secondhand smoke on a regular basis also puts you at risk for COPD.

The earlier you start smoking and the longer you smoke, the more likely you’ll be to get this disease. About half of all smokers develop COPD. Smoking early in life can stunt your lung development, increasing the risk for damage. The sooner you quit smoking, the greater your odds of avoiding this disease. Quitting can also slow the progression of COPD if you already have it.

Learn more: The smoking and COPD connection »

Smoking is the number one risk factor for COPD, but you don’t have to be a smoker to get this disease. Another major cause is burning fuel indoors. This cause is more common in places where people often cook or heat their homes by burning fuel.

You can also develop COPD if you’ve been exposed to:

  • chemical fumes
  • dust
  • air pollution

The single best way to prevent COPD is to stop smoking. For some smokers, it can take 30 attempts to finally ditch the habit. But you can do it.

Here are a few tips to help you quit:

  • Don’t try to quit on your own. Get help from your doctor. Or ask for guidance from an organization like the American Lung Association or a local smoking cessation support group.
  • Write an action plan. Choose the method you’ll use to quit based on your doctor’s advice.
  • Pick a quit day. It’s harder to back out of your plan when you have a firm date on the calendar. Before that date, throw out every cigarette, ashtray, lighter, and anything else in your home or office that triggers your urge to smoke.
  • Choose a method. Medicines and nicotine replacement products like gum, patches, and lozenges can reduce your cravings, making it easier to quit.
  • Revisit your past attempts. If you’ve tried to quit before and failed, think about what went wrong—and what worked. Modify your strategy based on your notes.
  • Find a substitute. If you need something to occupy your hands and mouth, suck on a straw, sugarless lollipop, or coffee stirrer.
  • Keep busy. Find other ways to fill your free time. Read a magazine, take a walk, or call a friend. Choose activities where it would be hard to smoke.
  • Avoid situations where you used to smoke. Skip your morning cup of coffee, don’t sit in front of the TV, and avoid bars where smoking is allowed.
  • Distract yourself. When you feel the urge to smoke, get up and start a new activity. Do something that occupies both your mind and body. Meditate, cook dinner, or write in a journal.
  • Reward yourself. For every cigarette you don’t smoke, put a dime in a jar. Save up for something you’ve been wanting. If you smoked one pack a day, in just a year you’ll save nearly $2,000—enough for a vacation!

Cigarettes aren’t the only risks for COPD. Also try to avoid irritants in the air, like pollution and chemical fumes. If your job involves breathing in these irritants, ask your manager about wearing a mask or other protective gear.

Check out: 15 tips from real people on how to quit smoking »

If you’re a smoker or you have a family history of AATD, see your doctor. COPD is a progressive disease. It gets worse over time. The sooner you take steps to protect your lungs, the less damage COPD will cause.

Your doctor will do lung function, imaging, and blood tests to see how well your lungs are working, and how much oxygen is getting into your body. These tests can show whether you have COPD. If you do have this condition, you can take medicines like bronchodilators or steroids to relax your airways and make it easier to breathe.

Keep reading: COPD: Tests and diagnosis »