Asthma is a common long-term inflammatory disease of the airways of the lungs. Asthma occurs when allergens, pollen, dust, or other particles, are inhaled into the lungs, causing the bronchioles to constrict and produce mucus, which then restricts oxygen flow to the alveoli. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, coughing, chest tightness, and shortness of breath. These may occur a few times a day or a few times per week. Depending on the person, asthma symptoms may become worse at night or with exercise.
Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide, or both cannot be kept at normal levels. A drop in the oxygen carried in the blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type 1 or Type 2, based on whether there is a high carbon dioxide level, and can be acute or chronic. In clinical trials, the definition of respiratory failure usually includes increased respiratory rate, abnormal blood gases, and evidence of increased work of breathing. Respiratory failure causes an altered state of consciousness due to ischemia in the brain.
Bronchiectasis is a disease in which there is permanent enlargement of parts of the airways of the lung. Symptoms typically include a chronic cough with mucus production. Other symptoms include shortness of breath, coughing up blood, and chest pain. Wheezing and nail clubbing may also occur. Those with the disease often get lung infections.
Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins. It causes difficulty in breathing which ranges from mild to severe.
Chlamydia pneumoniae is a species of Chlamydia, an obligate intracellular bacterium that infects humans and is a major cause of pneumonia. It was known as the Taiwan acute respiratory agent (TWAR) from the names of the two original isolates – Taiwan (TW-183) and an acute respiratory isolate designated AR-39. Briefly, it was known as Chlamydophila pneumoniae, and that name is used as an alternate in some sources. In some cases, to avoid confusion, both names are given.
Bronchoconstriction is the constriction of the airways in the lungs due to the tightening of surrounding smooth muscle, with consequent coughing, wheezing, and shortness of breath.
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.
Bronchoalveolar lavage (BAL), also known as bronchoalveolar washing, is a diagnostic method of the lower respiratory system in which a bronchoscope is passed through the mouth or nose into an appropriate airway in the lungs, with a measured amount of fluid introduced and then collected for examination. This method is typically performed to diagnose pathogenic infections of the lower respiratory airways, though it also has been shown to have utility in diagnosing interstitial lung disease. Bronchoalveolar lavage can be a more sensitive method of detection than nasal swabs in respiratory molecular diagnostics, as has been the case with SARS-CoV-2 where bronchoalveolar lavage samples detect copies of viral RNA after negative nasal swab testing.
Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterised by an exaggerated response of the immune system to the fungus Aspergillus. It occurs most often in people with asthma or cystic fibrosis. Aspergillus spores are ubiquitous in soil and are commonly found in the sputum of healthy individuals. A. fumigatus is responsible for a spectrum of lung diseases known as aspergilloses.
Reslizumab, sold under the brand names Cinqair and Cinqaero, is a humanized monoclonal antibody against human interleukin-5 (IL-5). Reslizumab binds specifically to IL-5, a key cytokine responsible for the differentiation, maturation, recruitment and activation of human eosinophils. By binding to human IL-5, it blocks its biological function; consequently survival and activity of eosinophils are reduced. The benefits with reslizumab are its ability to reduce the exacerbation rate and improve lung function and asthma-related quality of life in patients with severe eosinophilic asthma and with at least one previous asthma exacerbation in the preceding year. The most common side effects are increased blood creatine phosphokinase, myalgia and anaphylactic reactions.
Bronchoscopy is an endoscopic technique of visualizing the inside of the airways for diagnostic and therapeutic purposes. An instrument (bronchoscope) is inserted into the airways, usually through the nose or mouth, or occasionally through a tracheostomy. This allows the practitioner to examine the patient's airways for abnormalities such as foreign bodies, bleeding, tumors, or inflammation. Specimens may be taken from inside the lungs. The construction of bronchoscopes ranges from rigid metal tubes with attached lighting devices to flexible optical fiber instruments with realtime video equipment.
Obstructive lung disease is a category of respiratory disease characterized by airway obstruction. Many obstructive diseases of the lung result from narrowing (obstruction) of the smaller bronchi and larger bronchioles, often because of excessive contraction of the smooth muscle itself. It is generally characterized by inflamed and easily collapsible airways, obstruction to airflow, problems exhaling, and frequent medical clinic visits and hospitalizations. Types of obstructive lung disease include asthma, bronchiectasis, bronchitis and chronic obstructive pulmonary disease (COPD). Although COPD shares similar characteristics with all other obstructive lung diseases, such as the signs of coughing and wheezing, they are distinct conditions in terms of disease onset, frequency of symptoms, and reversibility of airway obstruction. Cystic fibrosis is also sometimes included in obstructive pulmonary disease.
Williams–Campbell syndrome (WCS) is a disease of the airways where cartilage in the bronchi is defective. It is a form of congenital cystic bronchiectasis. This leads to collapse of the airways and bronchiectasis. It acts as one of the differential to allergic bronchopulmonary aspergillosis. WCS is a deficiency of the bronchial cartilage distally.
Vocal cord dysfunction (VCD) is a condition affecting the vocal cords. It is characterized by abnormal closure of the vocal folds, which can result in significant difficulties and distress during breathing, particularly during inhalation.
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by chronic 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.
Tracheobronchomalacia (TBM) is a condition characterized by flaccidity of the tracheal support cartilage which leads to tracheal collapse. This condition can also affect the bronchi. There are two forms of this condition: primary TBM and secondary TBM. Primary TBM is congenital and starts as early as birth. It is mainly linked to genetic causes. Secondary TBM is acquired and starts in adulthood. It is mainly developed after an accident or chronic inflammation.
Chronic Mycoplasma pneumonia and Chlamydia pneumonia infections are associated with the onset and exacerbation of asthma. These microbial infections result in chronic lower airway inflammation, impaired mucociliary clearance, an increase in mucous production and eventually asthma. Furthermore, children who experience severe viral respiratory infections early in life have a high possibility of having asthma later in their childhood. These viral respiratory infections are mostly caused by respiratory syncytial virus (RSV) and human rhinovirus (HRV). Although RSV infections increase the risk of asthma in early childhood, the association between asthma and RSV decreases with increasing age. HRV on the other hand is an important cause of bronchiolitis and is strongly associated with asthma development. In children and adults with established asthma, viral upper respiratory tract infections (URIs), especially HRVs infections, can produce acute exacerbations of asthma. Thus, Chlamydia pneumoniae, Mycoplasma pneumoniae and human rhinoviruses are microbes that play a major role in non-atopic asthma.
Plastic bronchitis (PB) is a disorder in which branching casts of the airways are expectorated. PB is not a single disease with a defined mechanism that explains the cast formation in all conditions. Examples of diseases associated with expectoration of casts, and which sometimes are labeled PB include tuberculosis, atypical mycobacterial disease, allergic bronchopulmonary aspergillosis, and asthma.
In clinical guidelines chronic cough is defined as a cough lasting more than 8 weeks in adults and more than 4 weeks in children. there are studies suggest that a chronic cough must persist upwards of three months. The prevalence of chronic cough is about 10% although the prevalence may differ depending on definition and geographic area. Chronic cough is a common symptom in several different respiratory diseases like COPD or pulmonary fibrosis but in non-smokers with a normal chest x-ray chronic cough are often associated with asthma, rhinosinusitis, and gastroesophageal reflux disease or could be idiopathic. Generally, a cough, for example after an upper respiratory tract infection, lasts around one to two weeks; however, chronic cough can persist for an extended period of time, several years in some cases. The current theory about the cause of chronic cough, independent of associated condition, is that it is caused by a hypersensitivity in the cough sensory nerves, called cough hypersensitivity syndrome. There are a number of treatments available, depending on the associated disease but the clinical management of the patients remains a challenge. Risk factors include exposure to cigarette smoke, and exposure to pollution, especially particulates.
An anti-asthmatic agent, also known as an anti-asthma drug, refers to a drug that can aid in airway smooth muscle dilation to allow normal breathing during an asthma attack or reduce inflammation on the airway to decrease airway resistance for asthmatic patients, or both. The goal of asthmatic agents is to reduce asthma exacerbation frequencies and related hospital visits.
