Pulmonary diseases are some of the most common medical conditions in the world. Tens of millions of people suffer from lung diseases in the US UU Smoking, infections and genetics are responsible for most lung diseases.
The lungs are part of a complex apparatus, which expands and relaxes thousands of times each day to bring oxygen and expel carbon dioxide. Lung disease may be due to problems anywhere in this system.
Lung diseases that affect the respiratory tract
The trachea (air duct) branches into tubes called bronchi, which in turn branch out to become progressively smaller tubes along the lungs. Diseases that affect the respiratory tract include:
Asthma: the airways are inflamed persistently and, on occasion, they may suffer spasms, which causes wheezing and difficulty breathing. Allergies, infections or contamination can trigger asthma symptoms.
Chronic obstructive pulmonary disease (COPD): lung conditions defined by the inability to exhale normally, which causes difficulty in breathing.
Chronic bronchitis: a form of COPD characterized by a chronic productive cough.
Emphysema: lung damage allows air to be trapped in the lungs in this form of COPD. The difficulty to blow the air is its hallmark.
Acute bronchitis: a sudden infection of the respiratory tract, usually by a virus.
Cystic fibrosis: a genetic condition that causes the deficient removal of mucus from the bronchi. Accumulated mucus results in repeated lung infections.
Lung diseases that affect the air sacs (alveoli)
The airways eventually branch into tiny tubes (bronchioles) that end in clusters of air sacs called alveoli. These air sacs make up most of the lung tissue. Lung diseases that affect the alveoli include:
Pneumonia: an infection of the alveoli, usually by bacteria.
Tuberculosis: a slowly progressive pneumonia caused by the bacterium Mycobacterium tuberculosis.
Emphysema results from damage to the brittle connections between the alveoli. Smoking is the usual cause. (Emphysema also limits the flow of air, also affecting the airways).
Pulmonary edema: the fluid leaves the small blood vessels of the lung to the air sacs and the surrounding area. One form is caused by heart failure and back pressure in the blood vessels of the lungs; in another form, the direct lesion to the lung causes the leakage of fluid.
Lung cancer has many forms and can develop anywhere in the lungs. Most of the time, it is located in the main part of the lung, in or near the air sacs. The type, location and spread of lung cancer determine treatment options.
Acute respiratory distress syndrome (ARDS): severe and sudden injury to the lungs caused by a serious illness. Life support with mechanical ventilation is usually needed to survive until the lungs recover.
Pneumoconiosis: category of conditions caused by the inhalation of a substance that injures the lungs. Examples include black lung powder inhaled coal dust and inhaled asbestos dust asbestosis.
Lung diseases that affect the interstitium
The interstitium is the microscopically thin and delicate lining between the air sacs of the lungs (alveoli). Tiny blood vessels pass through the interstitium and allow the exchange of gases between the alveoli and the blood. Various lung diseases affect the interstitium:
Interstitial lung disease (EPI): a wide collection of lung conditions that affect the interstitium. Sarcoidosis, idiopathic pulmonary fibrosis and autoimmune disease are among the many types of PID.
Pneumonias and pulmonary edema may also affect the interstitium.
Lung diseases that affect blood vessels
The right side of the heart receives blood with little oxygen from the veins. Pumping blood to the lungs through the pulmonary arteries. These blood vessels can also suffer diseases.
Pulmonary embolism (PE): A blood clot forms (usually in a deep vein in the leg, deep vein thrombosis), travels to the heart, and is pumped into the lungs. The clot is lodged in a pulmonary artery, often causing difficulty in breathing and low levels of oxygen in the blood.
Pulmonary hypertension: several conditions can cause high blood pressure in the pulmonary arteries. This can cause shortness of breath and pain in the chest. When no cause is identified, the condition is called hi