Most people take effortless breathing for granted. When your lungs are healthy, they expand easily into your chest cavity as you inhale, taking in vital oxygen for your blood to deliver throughout your body. With each exhalation, your lungs deflate and release carbon dioxide, a respiratory waste product.

When you run to catch the bus or climb a steep flight of stairs, your breathing naturally adapts to meet the extra demand on your heart and lungs. You may feel slightly out of breath, but not actually short of breath, because healthy lungs have a breathing reserve (extra air volume you can use after a normal exhalation). Shortness of breath, also called dyspnea – a feeling of extreme tightness in the chest, difficulty breathing and what's sometimes referred to as "air hunger" – is a hallmark of respiratory disease.

The lower respiratory system includes the windpipe, or trachea, which separates into a pair of bronchial tubes that lead down into either lung. Within the lungs, the bronchial tubes divide into multiple smaller branches called bronchioles. Stemming from these narrowing branches are small air sacs, called alveoli. Tiny blood vessels called capillaries surround the alveoli. These capillaries let oxygen and carbon dioxide pass back and forth between the lungs and bloodstream.

Below are major types of respiratory diseases, early symptoms to recognize, tests you need for the right diagnosis, and treatments and self-management strategies to restore your breathing as much as possible.

Various conditions affect different parts of your respiratory system and hinder your ability to breathe. These conditions can be chronic or infectious. Chronic lung diseases fall into one of two main classes: obstructive or restrictive. People with weakened lungs and immune systems are more vulnerable to infectious respiratory conditions . Some individuals have multiple lung conditions.

Obstructive lung diseases involve blocked or narrowed airways, making it difficult for the lungs to exhale and exchange old air for fresh air.

Chronic obstructive pulmonary disease, or COPD, makes airways and air sacs less elastic, inflames the airway walls and clogs the lungs with excess mucus. It encompasses emphysema and chronic bronchitis. In emphysema, the tiny air sacs of the lungs are damaged. Chronic bronchitis involves inflammation of the air sacs and excessive mucus production in the lungs.

In the U.S., about 12 million adults are diagnosed with COPD annually, and 120,000 people die from it, according to the National Institutes of Health. "COPD is one of the worst diseases out there," says Dr. Kyle Hogarth, a professor of medicine, director of bronchoscopy and co-director of lung cancer screening at University of Chicago Medical Center. He notes that it's the third leading cause of death.

COPD death rates have decreased significantly for men but only slightly for women. For people with COPD over the age of 25, the death rate for men declined by 22.5% from 2000 to 2014. However, the death rate for women only declined by roughly 4% during that period.

Alpha-1 antitrypsin deficiency is a genetic condition that puts people at risk for lung and liver disease. Alpha-1 antitrypsin is a protein produced by the body to protect various organs from damage caused by the body's own immune system. AATD, when this protein is lacking, is a not-so-rare disease, says Dr. Brooks Kuhn, a pulmonology and critical care specialist at UC Davis Medical Center in Sacramento, California, and co-director of the alpha-1 antitrypsin deficiency clinic at UC Davis.

"The sad reality is we have only identified probably a very small fraction of patients with alpha-1 antitrypsin deficiency," Kuhn says. Various estimates suggest that maybe 100,000 people. "We probably have about 12,000 or so identified currently." Although it can lead to COPD, alpha-1 antitrypsin deficiency itself requires a different, specialized type of treatment.

Asthma, also called reactive airway disease, involves inflammation of the airways, usually in response to triggers such as pollen or dust, cold weather, stress or chemical fumes. More than 19 million adults in the U.S. have asthma, according to the Centers for Disease Control and Prevention. Asthma is also a common childhood condition, with 5.5 million kids currently affected. Some children outgrow asthma. However, asthma may seemingly go away temporarily only to reappear later, or persist continuously.

Bronchiectasis causes abnormal widening of the airways, making it difficult to rid the lower airways of mucus and phlegm, which raises the risk of infection.

Cystic fibrosis is a genetic condition that causes mucus in organs, including the lungs, to become thick and sticky. Respiratory complications include infections, inflammation and respiratory failure.

Pulmonary fibrosis scars and stiffens lung tissue, restricting lung movement and function. It is a type of interstitial lung disease, the umbrella term for more than 200 disorders that cause progressive and usually irreversible scarring, or fibrosis, of the lungs. "That causes the volume of the lungs to get smaller and smaller," saysDr. Jared Chiarchiaro,an assistant professor at the University of Pittsburgh School of Medicine and a pulmonary, allergy and critical care physician at the University of Pittsburgh Medical Center.

The most common type of pulmonaryfibrosis is called idiopathic pulmonary fibrosis. Idiopathic means that the cause is unknown, rather than being a complication of another condition. An estimated 100,000 people have IPF in the U.S., and 30,000 to 40,000 new cases are diagnosed each year, according to the NIH.

Sarcoidosis is a rare condition that can arise in different parts of the body. Sarcoidosis involves the growth of tiny inflammatory cells that may affect a number of organs, most often the lungs.

Lung cancer affects the lungs in multiple ways. Tumors may block airways, or fluid can collect around either lung, making expansion difficult. Lung cancer can also cause inflammation in the respiratory system.

Infectious lung conditions are usually temporary, although some respiratory infections can become chronic or frequently recur.

Pneumonia is a lung infection most commonly caused by bacteria or viruses. People with chronic respiratory conditions like COPD are more vulnerable to developing pneumonia.

Tuberculosis is a bacterial infection that affects the lungs and other parts of the body. TB can be inactive, or latent, for many years.

Causes

Certain factors are known to contribute to respiratory disease. For others, the cause is unclear. These are some causes or risk factors:

Symptoms can vary by the type of respiratory condition, although some symptoms are common to several disorders.

A correct diagnosis is essential to treat respiratory disease promptly and appropriately. Diagnosis can be straightforward; however, misdiagnosis, under-diagnosis (with cases being missed) and delayed diagnosis can occur, Hogarth says. The reasons for this include disease complexity and overlap among diseases.

Your doctor will do a physical exam and review your medical and family history. He or she will ask you about smoking, childhood conditions like asthma and other risk factors and details about the timing and severity of your symptoms. You may undergo one or more of the following diagnostic tests and procedures:

Depending on your respiratory condition, medications can include an assortment of inhalers, oral drugs and intravenous treatments. Your doctor should explain why specific medications are prescribed, and their potential benefits and side effects. Some examples include, by condition:

Asthma. Inhalers and nebulizers are key components of asthma treatment. Long-term asthma control medications include inhaled corticosteroids, leukotriene modulators (like Singulair) that prevent asthma symptoms, theophylline, and long-term beta agonists, or LABAs, that relax airway muscles (like Serevent). Combination inhalers include both a LABA and corticosteroid.

Quick-relief or rescue asthma medications provide rapid, short-term symptom relief during asthma flares. Albuterol and Atrovent are types of inhaled rescue drugs. Oral and IV steroids may be prescribed on a short-term basis to treat severe asthma symptoms.

COPD. A wide range of inhalers, nebulizers, oral medications and injections are used to treat COPD, depending on severity and symptoms. Clinicians use guidelines from the Global Initiative for Chronic Obstructive Lung Disease, known as the GOLD guidelines, to prescribe COPD medications.

Idiopathic pulmonary fibrosis. Two oral medications are currently approved by the Food and Drug Administration to treat idiopathic pulmonary fibrosis: pirfenidone (Esbriet) and nintedanib (Ofev).

Alpha-1 antitrypsin deficiency. "Drugs are available where we functionally give people back alpha-1 antitrypsin," Kuhn says. "And you're actually able to augment their deficiency to some degree." Augmentation therapy involves a weekly IV infusion, which some patients learn to manage at home.

Cystic fibrosis. In October, the FDA announced its approval of a three-drug combination called Trikafta as a breakthrough therapy for the genetic condition.

Smoking cessation. It's critical for people with respiratory diseases to quit smoking and avoid further compromising their breathing. However, it can be difficult for long-term smokers, who may need medications and counseling to help them quit.

Supplemental oxygen. People with advanced COPD or pulmonary fibrosis may benefit from using supplemental oxygen to deliver enough oxygen to the body and help relieve their symptoms.

Pulmonary rehabilitation. Pulmonary rehab isprobably the most underutilized tool for COPD, Hogarth says. "You're going to the gym with a trainer and insurance is paying for it," he says. Officially called medically supervised exercise, it involves up to 36 covered sessions with a certified program, offered in many hospitals and outpatient settings.

Pulmonary rehab works, and it's liberating, Hogarth says: "This is the difference between being able to walk around the grocery store and push the cart and then load the groceries in your car and drive home, versus struggling to breathe while getting out of the car and walking through the grocery store." You still may not be able to easily go up the stairs, but it becomes less of a struggle.

Hogarth also reports similar interest among his patients. "Centers will charge you an insane amount of cash," he says, as insurance will not cover interventions that are not backed by evidence. "They will infuse stem cells telling you you'll breathe better – and shock of shocks, you don't."

Over the long term, you can take steps to stay on top of respiratory conditions such as asthma and COPD and reduce their impact on your day-to-day life In other cases, disease progression can lead to unavoidable lifestyle changes.

Patient education, digital technology and asthma action plans can improve asthma control and quality of life, says Dr. Sunit Jariwala, director of allergy/immunology research at Montefiore Medical Centerand Albert Einstein College of Medicine in New York City.

"In the Bronx, asthma is epidemic," Jariwala says. "Almost every community has emergency room visit rates at triple the state average." In 2011, he and colleagues founded the Montefiore Asthma Center to address the situation.

If you're diagnosed with asthma, there's a lot to learn. Education on how to take medications, the difference between rescue and control medications, how to use medication spacers and respiratory peak flow meters, and avoiding environmental triggers is essential.

Having a personalized asthma action plan in place can help control your asthma and prevent attacks. An asthma action plan spells out details such as your known environmental triggers, instructions for prescribed controller and rescue medications, when to use them and potential side effects, medication use around exercise, and when to call your health care provider or go immediately to the emergency room. You can downloadasthma action plan forms from the CDC website.

Digital technology can improve asthma self-management. Jariwala and his colleagues at Montefiore have developed apps for kids and adults with asthma. The educational apps offer information, medication reminders and animated features for children. You can download the free ASTHMAXcel and ASTHMAXcel Adventures apps for mobile devices.

Your treatment team may include the following clinicians:

If you have COPD, ongoing support can help you manage better at home and avoid a cycle of frequent disease exacerbations and hospital readmissions.

The UC Davis ROAD (reversible obstructive airway disease) program, like similar COPD programs, takes a multidisciplinary approach to individualizing treatment, educating patients and following up with calls after discharge to help with the transition to home. Having a landing spot for patients when they leave the hospital, and getting them into the clinic early when symptoms arise, helps people with COPD remain outpatients and stay out of the hospital, Kuhn says.

For any chronic respiratory condition, joining an online or in-person support group lets you meet peers and share information and resources. Medical centers that focus on less-common conditions can connect you with related support groups.