Respiratory syncytial virusRespiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. Its name is derived from the large cells known as syncytia that form when infected cells fuse. RSV is a common cause of respiratory hospitalization in infants, and reinfection remains common in later life: it is a notable pathogen in all age groups.
Pathogenic bacteriaPathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of these pathogenic species in humans is estimated to be fewer than a hundred. By contrast, several thousand species are part of the gut flora present in the digestive tract.
WheezeA wheeze is a clinical symptom of a continuous, coarse, whistling sound produced in the respiratory airways during breathing. For wheezes to occur, some part of the respiratory tree must be narrowed or obstructed (for example narrowing of the lower respiratory tract in an asthmatic attack), or airflow velocity within the respiratory tree must be heightened. Wheezing is commonly experienced by persons with a lung disease; the most common cause of recurrent wheezing is asthma, though it can also be a symptom of lung cancer, congestive heart failure, and certain types of heart diseases.
COVID-19Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the virus SARS-CoV-2. The first known case was identified in Wuhan, China, in December 2019. The disease quickly spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‐19 are variable but often include fever, cough, headache, fatigue, breathing difficulties, loss of smell, and loss of taste. Symptoms may begin one to fourteen days after exposure to the virus. At least a third of people who are infected do not develop noticeable symptoms.
Granulomatosis with polyangiitisGranulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis (WG), after the Nazi German physician Friedrich Wegener, is a rare long-term systemic disorder that involves the formation of granulomas and inflammation of blood vessels (vasculitis). It is an autoimmune disease and a form of vasculitis that affects small- and medium-size vessels in many organs but most commonly affects the upper respiratory tract, lungs and kidneys.
Nail clubbingNail clubbing, also known as digital clubbing or clubbing, is a deformity of the finger or toe nails associated with a number of diseases, mostly of the heart and lungs. When it occurs together with joint effusions, joint pains, and abnormal skin and bone growth it is known as hypertrophic osteoarthropathy. Clubbing is associated with lung cancer, lung infections, interstitial lung disease, cystic fibrosis, or cardiovascular disease. Clubbing may also run in families, and occur unassociated with other medical problems.
Viral diseaseA viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. Basic structural characteristics, such as genome type, virion shape and replication site, generally share the same features among virus species within the same family. Double-stranded DNA families: three are non-enveloped (Adenoviridae, Papillomaviridae and Polyomaviridae) and two are enveloped (Herpesviridae and Poxviridae).
Respiratory systemThe respiratory system (also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for gas exchange in animals and plants. The anatomy and physiology that make this happen varies greatly, depending on the size of the organism, the environment in which it lives and its evolutionary history. In land animals the respiratory surface is internalized as linings of the lungs. Gas exchange in the lungs occurs in millions of small air sacs; in mammals and reptiles these are called alveoli, and in birds they are known as atria.
EpiglottitisEpiglottitis is the inflammation of the epiglottis—the flap at the base of the tongue that prevents food entering the trachea (windpipe). Symptoms are usually rapid in onset and include trouble swallowing which can result in drooling, changes to the voice, fever, and an increased breathing rate. As the epiglottis is in the upper airway, swelling can interfere with breathing. People may lean forward in an effort to open the airway. As the condition worsens, stridor and bluish skin may occur.
Passive smokingPassive smoking is the inhalation of tobacco smoke, commonly called secondhand smoke (SHS) or environmental tobacco smoke (ETS), by persons other than the active smoker. It occurs when tobacco smoke diffuses into the surrounding atmosphere as an aerosol pollutant, which leads to its inhalation by nearby bystanders within the same environment. Exposure to secondhand tobacco smoke causes many of the same diseases caused by active tobacco smoking, although to a lower prevalence due to the reduced concentration of smoke that enters the airway.
