Lung cancer, also known as lung carcinoma, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged airway cells gain the ability to multiply unchecked, causing the growth of a tumor. Without treatment, tumors spread throughout the lung, damaging lung function. Eventually lung tumors metastasize, spreading to other parts of the body.
A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three phases: an inhalation, a forced exhalation against a closed glottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.
Shortness of breath (SOB), also medically known as dyspnea or dyspnoea, is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger". The tripod position is often assumed to be a sign.
Pleurisy, also known as pleuritis, is inflammation of the membranes that surround the lungs and line the chest cavity (pleurae). This can result in a sharp chest pain while breathing. Occasionally the pain may be a constant dull ache. Other symptoms may include shortness of breath, cough, fever, or weight loss, depending on the underlying cause. Pleurisy can be caused by a variety of conditions, including viral or bacterial infections, autoimmune disorders, and pulmonary embolism.
Asbestosis is long-term inflammation and scarring of the lungs due to asbestos fibers. Symptoms may include shortness of breath, cough, wheezing, and chest tightness. Complications may include lung cancer, mesothelioma, and pulmonary heart disease.
Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of respiratory diseases affecting the interstitium and space around the alveoli of the lungs. It concerns alveolar epithelium, pulmonary capillary endothelium, basement membrane, and perivascular and perilymphatic tissues. It may occur when an injury to the lungs triggers an abnormal healing response. Ordinarily, the body generates just the right amount of tissue to repair damage, but in interstitial lung disease, the repair process is disrupted, and the tissue around the air sacs (alveoli) becomes scarred and thickened. This makes it more difficult for oxygen to pass into the bloodstream. The disease presents itself with the following symptoms: shortness of breath, nonproductive coughing, fatigue, and weight loss, which tend to develop slowly, over several months. The average rate of survival for someone with this disease is between three and five years. The term ILD is used to distinguish these diseases from obstructive airways diseases.
Pulmonary fibrosis is a condition in which the lungs become scarred over time. Symptoms include shortness of breath, a dry cough, feeling tired, weight loss, and nail clubbing. Complications may include pulmonary hypertension, respiratory failure, pneumothorax, and lung cancer.
Chemical pneumonitis is inflammation of the lung caused by aspirating or inhaling irritants. It is sometimes called a "chemical pneumonia", though it is not infectious. There are two general types of chemical pneumonitis: acute and chronic.
Hyperoxia occurs when cells, tissues and organs are exposed to an excess supply of oxygen (O2) or higher than normal partial pressure of oxygen.
Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a syndrome caused by the repetitive inhalation of antigens from the environment in susceptible or sensitized people. Common antigens include molds, bacteria, bird droppings, bird feathers, agricultural dusts, bioaerosols and chemicals from paints or plastics. People affected by this type of lung inflammation (pneumonitis) are commonly exposed to the antigens by their occupations, hobbies, the environment and animals. The inhaled antigens produce a hypersensitivity immune reaction causing inflammation of the airspaces (alveoli) and small airways (bronchioles) within the lung. Hypersensitivity pneumonitis may eventually lead to interstitial lung disease.
Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris, aspiration, herbicides or fluorocarbons and some systemic diseases. If unresolved, continued inflammation can result in irreparable damage such as pulmonary fibrosis.
Cryptogenic organizing pneumonia (COP), formerly known as bronchiolitis obliterans organizing pneumonia (BOOP), is an inflammation of the bronchioles (bronchiolitis) and surrounding tissue in the lungs. It is a form of idiopathic interstitial pneumonia.
Farmer's lung is a hypersensitivity pneumonitis induced by the inhalation of biologic dusts coming from hay dust or mold spores or any other agricultural products. It results in a type III hypersensitivity inflammatory response and can progress to become a chronic condition which is considered potentially dangerous.
Occupational lung diseases comprise a broad group of diseases, including occupational asthma, industrial bronchitis, chronic obstructive pulmonary disease (COPD), bronchiolitis obliterans, inhalation injury, interstitial lung diseases, infections, lung cancer and mesothelioma. These can be caused directly or due to immunological response to an exposure to a variety of dusts, chemicals, proteins or organisms. Occupational cases of interstitial lung disease may be misdiagnosed as COPD, idiopathic pulmonary fibrosis, or a myriad of other diseases; leading to a delay in identification of the causative agent.
Bird fancier's lung (BFL), also known as bird breeder's lung, is a type of hypersensitivity pneumonitis. It can cause shortness of breath, fever, dry cough, chest pain, anorexia and weight loss, fatigue, and progressive pulmonary fibrosis. It is triggered by exposure to avian proteins present in the dry dust of droppings or feathers of a variety of birds. The lungs become inflamed, with granuloma formation. It mostly affects people who work with birds or own many birds.
Restrictive lung diseases are a category of extrapulmonary, pleural, or parenchymal respiratory diseases that restrict lung expansion, resulting in a decreased lung volume, an increased work of breathing, and inadequate ventilation and/or oxygenation. Pulmonary function test demonstrates a decrease in the forced vital capacity.
Pulmonary toxicity is the medical name for side effects on the lungs.
Fibrothorax is a medical condition characterised by severe scarring (fibrosis) and fusion of the layers of the pleural space surrounding the lungs resulting in decreased movement of the lung and ribcage. The main symptom of fibrothorax is shortness of breath. There also may be recurrent fluid collections surrounding the lungs. Fibrothorax may occur as a complication of many diseases, including infection of the pleural space known as an empyema or bleeding into the pleural space known as a haemothorax.
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. GOLD 2024 defined COPD as a heterogeneous lung condition characterized by chronic respiratory symptoms due to abnormalities of the airways and/or alveoli (emphysema) that cause persistent, often progressive, airflow obstruction.
Acute inhalation injury may result from frequent and widespread use of household cleaning agents and industrial gases. The airways and lungs receive continuous first-pass exposure to non-toxic and irritant or toxic gases via inhalation. Irritant gases are those that, on inhalation, dissolve in the water of the respiratory tract mucosa and provoke an inflammatory response, usually from the release of acidic or alkaline radicals. Smoke, chlorine, phosgene, sulfur dioxide, hydrogen chloride, hydrogen sulfide, nitrogen dioxide, ozone, and ammonia are common irritants.
