Human respiratory system diseases can occur from intrinsic causes as well as the inhalation of foreign bodies. This page presents a sample of a few respiratory system diseases, their origins, and their treatment. The lung can also be injured in many other ways and material dealing with those diseases can be read about or studied in various textbooks of medicine and pulmonary disease.
Asthma, a common disease, can be due to external causes (such as allergens that are inhaled) or can be intrinsic. Airway obstruction with wheezing is the hallmark of this disease and can be controlled by medication or may subside spontaneously. A stepwise form of therapy with inhaled corticosteroid drugs and inhaled bronchodilators is effective treatment in most patients.
In addition to intrinsic respiratory system diseases, the lung can often be infected by material that is inhaled. Hence, the disease category pneumonias, which can result from the inhalation of bacteria or viruses. Pneumonia is usually characterized by fever, cough, cutting chest (pleuritic) pain, involvement of a segment or lobe of a lung on chest x-ray, and a positive smear or culture of the sputum. These are treated with antibiotics to which these organisms are sensitive. Today, most pneumonias are easily treated and resolve quickly with treatment.
Chronic obstructive pulmonary disease (COPD)
Chronic obstructive pulmonary disease (COPD) is an obstructive airway disease that is often due to cigarette smoking and is characterized by cough and sputum production (which is often purulent in character) as well as shortness of breath (dyspnea).
It is composed of two respiratory system diseases, chronic bronchitis and emphysema, and the term COPD is used because emphysema has no clinical definition. It can also be treated with inhaled medications called anticholinergics, but it does not tend to resolve with therapy. Treatment tends to suppress the disease, but it continues to progress throughout the patient’s life. Its progression is slowed by cessation of cigarette smoking.
Pulmonary emboli are caused by obstruction of the pulmonary arteries and or their branches by circulating materials, usually clots which come from the heart or from diseased vessels in the thigh. This disease can be characterized by a multitude of non-specific signs and symptoms, including coughing up blood (unusual), shortness of breath, chest pain, and swelling and pain in the lower extremities.
Because of the non-specificity of these symptoms, they require physicians’ suspicion in order to be diagnosed in a rapid manner. This diagnosis is often missed with dire consequences. It is treated with anticoagulants for a period of time long enough for the obstructive lung vessel to recanalize. The underlying problem causing the pulmonary embolism is also treated.
Lung cancer, one of the best-known and most devastating of the respiratory system diseases, is characterized by abnormally growing lung tissue (malignant) which slowly, but incessantly invades normal lung tissue and eventually results in tissue death. The major cause of lung cancer in the world is cigarette smoking. With recent laws enacted to outlaw smoking in most public areas that are enclosed and with the active government campaigns to make the public aware of the relationship between cigarette smoking and lung cancer, the death rate from lung cancer, which has the highest death rate of all malignant tumors, has leveled slightly. Although treatment regimens are improving, the clinical outcomes associated with this disease are poor. Hopefully, current trends in the decrease in cigarette smoking will continue.
Occupational lung disease
The lung is often injured by foreign substances that are inhaled in the workplace (occupational lung disease). These diseases are varied and are caused by inhalation of gases as well as particulate matter. (e.g. coal). The major method of dealing with these diseases is prevention. Their treatment is often less than satisfactory. Modern laws instituted to combat the spread of these diseases are quite good and government programs to compensate older workers have compensated these workers for their disability.