An estimated 12 million Americans are currently diagnosed with chronic obstructive pulmonary disease (COPD) and another 12 million more may have the disease without knowing it, according to the National Heart, Lung and Blood Institute. Marked by a severe difficulty with breathing, COPD is a chronic lung disease that can lead to lifelong disability. By the time symptoms appear, your lungs have already been significantly damaged. However, you can take control of the disease with a combination of medical intervention and long-term lifestyle changes.

The airways that allow oxygen to travel in and out of your lungs are usually elastic. This allows the air to move more freely, just as it would flow easily in and out of a balloon. COPD occurs when the airways have swollen and lose elasticity, diminishing the lungs’ ability to pump air. The constricted passages lead to difficulty breathing and painful respiratory symptoms such as coughing or wheezing.

COPD typically refers to two types of illnesses: chronic asthmatic bronchitis and emphysema. Chronic asthmatic bronchitis constrains the airways that direct air to your lungs. A combination of inflammation and increased mucus production cuts down the amount of room for air to travel through these passageways. Emphysema primarily affects the air sacs in your lungs. These sacs, known as alveoli, hold oxygen for the body to process. When emphysema damages the walls of the alveoli, the lungs have a harder time converting the oxygen and exhaling carbon dioxide.

The symptoms of COPD generally worsen over time, and they occasionally flare in periods of exacerbation. The affects of COPD vary depending on the type, but most people experience common symptoms such as chronic cough, wheezing, shortness of breath and chest tightness. Many people with COPD will also feel fatigue, due to the lack of oxygen.

Long term smoking is the number one cause of COPD. High frequency smoking over an extended period of time increases a person’s risk for developing COPD. Toxins in cigarette smoke, including tar and cyanide, progressively cause lung damage. Exposure to secondhand smoke can also increase an individual’s risk for COPD.

Additional causes can include chronic exposure to harmful airborne substances, including gases and fumes in the work place, air pollution and unventilated smoke from fires. COPD may also develop due to a rare genetic disorder known as alpha-1 antitrypsin deficiency.

The first step toward controlling COPD is to stop smoking. Continuing to smoke will cause further damage to an already weak respiratory system. Refusing to stop smoking may lead to a total loss of the ability to breathe.

The lung damage from COPD is irreversible, but an adequate treatment regimen can help an individual cope with the symptoms and prevent further damage. Medications can help reduce inflammation or relax the muscles around your airways, which would ease the process of breathing. Some people may need devices to provide supplemental oxygen to their blood, such as portable oxygen units. In severe cases, the doctor may recommend surgical intervention. One procedure known as a lung volume reduction surgery involves removing parts of diseased lung to make more room for air. On some occasions, a lung transplant may be necessary.