IRDS begins shortly after birth and is manifest by fast breathing, more than 60 per minute, a fast heart rate, chest wall retractions (recession), expiratory grunting, nasal flaring and blue discoloration of the skin during breathing efforts.

As the disease progresses, the baby may develop ventilatory failure (rising carbon dioxide concentrations in the blood), and prolonged cessations of breathing ("apnea"). Whether treated or not, the clinical course for the acute disease lasts about 2 to 3 days. During the first day the patient worsens and requires more support. During the second day the baby may be remarkably stable on adequate support and resolution is noted during the third day, heralded by a prompt diuresis. Despite huge advances in care, IRDS remains the most common single cause of death in the first month of life in the developed world. Complications include metabolic disorders (acidosis, low blood sugar), patent ductus arteriosus, low blood pressure, chronic lung changes, and bleeding in the brain. The disease is frequently complicated by prematurity and its additional defects in other organ function.

Infant respiratory distress syndrome (IRDS), also called neonatal respiratory distress syndrome (NRDS), respiratory distress syndrome of newborn, or increasingly surfactant deficiency disorder (SDD), and previously called hyaline membrane disease (HMD), is a syndrome in premature infants caused by developmental insufficiency of pulmonary surfactant production and structural immaturity in the lungs. It can also be a consequence of neonatal infection. It can also result from a genetic problem with the production of surfactant associated proteins. IRDS affects about 1% of newborn infants and is the leading cause of death in preterm infants. The incidence decreases with advancing gestational age, from about 50% in babies born at 26–28 weeks, to about 25% at 30–31 weeks. The syndrome is more frequent in infants of diabetic mothers and in the second born of premature twins.

IRDS is distinct from pulmonary hypoplasia, another leading cause of neonatal death that involves respiratory distress.

Respiratory disease is a medical term that encompasses pathological conditions affecting the organs and tissues that make gas exchange possible in higher organisms, and includes conditions of the upper respiratory tract, trachea, bronchi, bronchioles, alveoli, pleura and pleural cavity, and the nerves and muscles of breathing. Respiratory diseases range from mild and self-limiting, such as the common cold, to life-threatening entities like bacterial pneumonia, pulmonary embolism, acute asthma and lung cancer.

The study of respiratory disease is known as pulmonology. A doctor who specializes in respiratory disease is known as a pulmonologist, a chest medicine specialist, a respiratory medicine specialist, a respirologist or a thoracic medicine specialist.

Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.

Chronic respiratory diseases (CRDs) are diseases of the airways and other structures of the lung. This disease could be characterized by a high inflammatory cells recruitment (neutrophil) and/or destructive cycle of infection, (e.g. mediated by "Pseudomonas aeruginosa"). Some of the most common are asthma, chronic obstructive pulmonary disease, or acute respiratory distress syndrome . CRDs are not curable, however, various forms of treatment that help dilate major air passages and improve shortness of breath can help control symptoms and increase the quality of life for people with the disease.

it usually lasts for three months to two years

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.

Diagnosis of obstructive disease requires several factors depending on the exact disease being diagnosed. However one commonalty between them is an FEV1/FVC ratio less than 0.7, i.e. the inability to exhale 70% of their breath within one second.

Following is an overview of the main obstructive lung diseases. "Chronic obstructive pulmonary disease" is mainly a combination of chronic bronchitis and emphysema, but may be more or less overlapping with all conditions.

Alveolar capillary dysplasia (ACD, sometimes denoted ACDMPV when including misalignment of the pulmonary veins) is a type of diffuse developmental disorder of the lung. The other two diffuse developmental disorders are congenital acinar dysplasia and congenital alveolar dysplasia (CAD).

ACD or ACDMPV is the best studied diffuse developmental disorder. It is a very rare congenital malformation involving abnormal development of the capillary vascular system around the alveoli of the lungs. It is a rare cause of persistent pulmonary hypertension in infants. It also may be a rare cause of pulmonary hypoplasia.

Babies with ACD may appear normal at birth but within minutes or hours they develop respiratory distress with persistent pulmonary hypertension. ACD does not respond to standard therapies that resolve simple pulmonary hypertension. The lack of response is an important diagnostic clue.

In many patients, symptoms are present for a considerable time before diagnosis. The most common clinical features of IPF include the following:

- Age over 50 years

- Dry, non-productive cough on exertion

- Progressive exertional dyspnea (shortness of breath with exercise)

- Dry, inspiratory bibasilar "velcro-like" crackles on auscultation (a crackling sound in the lungs during inhalation similar to Velcro being torn apart slowly, heard with a stethoscope).

- Clubbing of the digits, a disfigurement of the finger tips or toes (see image)

- Abnormal pulmonary function test results, with evidence of restriction and impaired gas exchange.

Some of these features are due to chronic hypoxemia (oxygen deficiency in the blood), are not specific for IPF, and can occur in other pulmonary disorders. IPF should be considered in all patients with unexplained chronic exertional dyspnea who present with cough, inspiratory bibasilar crackles, or finger clubbing.

Assessment of "velcro" crackles on lung auscultation is a practical way to improve the earlier diagnosis of IPF. Fine crackles are easily recognized by clinicians and are characteristic of IPF.

If bilateral fine crackles are present throughout the inspiratory time and are persisting after several deep breaths, and if remaining present on several occasions several weeks apart in a subject aged ≥60 years, this should raise the suspicion of IPF and lead to consideration of an HRCT scan of the chest which is more sensitive than a chest X-ray. As crackles are not specific for IPF, they must prompt a thorough diagnostic process.

People affected by GLILD may have symptoms such as cough and breathlessness, but may also be asymptomatic, with the condition first detected through abnormalities on lung function tests or a CT scan of the lungs.

Symptoms of DPB include chronic sinusitis (inflamed paranasal sinuses), wheezing, crackles (respiratory sounds made by obstructions such as phlegm and secretions in the lungs), dyspnea (shortness of breath), and a severe cough that yields large amounts of sputum (coughed-up phlegm). There may be pus in the sputum, and affected individuals may have fever. Typical signs of DPB progression include (enlargement) of the bronchiolar passages and hypoxemia (low levels of oxygen in the blood). If DPB is left untreated, bronchiectasis will occur; it is characterized by dilation and thickening of the walls of the bronchioles, inflammatory damage to respiratory and terminal bronchioles, and pooling of mucus in the lungs. DPB is associated with progressive respiratory failure, hypercapnia (increased levels of carbon dioxide in the blood), and can eventually lead to pulmonary hypertension (high blood pressure in the pulmonary vein and artery) and cor pulmonale (dilation of the right ventricle of the heart, or "right heart failure").

The term "bronchiolitis" generally refers to inflammation of the bronchioles. DPB is classified as a form of "primary bronchiolitis", which means that the underlying cause of bronchiolitis is originating from or is confined to the bronchioles. Along with DPB, additional forms of primary bronchiolitis include bronchiolitis obliterans, follicular bronchiolitis, respiratory bronchiolitis, mineral dust airway disease, and a number of others. Unlike DPB, bronchiolitis that is not considered "primary" would be associated with diseases of the larger airways, such as chronic bronchitis.

Idiopathic pulmonary fibrosis (IPF) is a chronic irreversible and ultimately fatal disease characterized by a progressive decline in lung function. American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This official statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was approved by the ATS board of directors, June 2013 and by the ERS Steering Committee, March 2013. "Am Respir Crit Care Med." 188 (6): 733–748. September 15, 2013. The term pulmonary fibrosis means scarring of lung tissue and is the cause of worsening dyspnea (shortness of breath). Fibrosis is usually associated with a poor prognosis.

IPF belongs to a large group of more than 200 lung diseases known as interstitial lung diseases (ILDs), characterized by the involvement of lung interstitium. The interstitium, the tissue between the air sacs in the lung, is the primary site of injury in ILDs. However, these disorders frequently affect not only the interstitium, but also the airspaces, peripheral airways, and vessels. Lung tissue from people with IPF shows a characteristic histopathologic pattern known as usual interstitial pneumonia (UIP). UIP is therefore the pathologic counterpart of IPF. The term 'idiopathic' is used because the cause of pulmonary fibrosis is still unknown. IPF usually occurs in adults of between 50 and 70 years of age, particularly those with a history of cigarette smoking, and affects more men than women. The diagnosis of IPF requires exclusion of other known causes of ILDs and the presence of a typical radiological pattern identified through high resolution computed tomography (HRCT). In the right clinical setting, it is possible to make the diagnosis of IPF by HRCT alone, obviating the need for surgical lung biopsy.

Treatment to slow down the progression of the disease may include nintedanib or pirfenidone.

ACD commonly is diagnosed postmortem, by a pathologist.

Sometimes ACD is diagnosed clinically. This is common when there is a family history of ACD, but rare otherwise. A clinical differential diagnosis of ACD excludes fetal atelectasis.

ACD is not detectable by prenatal imaging. However, some babies with ACD have associated congenital malformations that are detectable by imaging. The identification of genes involved in ACD offers the potential for prenatal testing and genetic counseling.

Granulomatous–lymphocytic interstitial lung disease (GLILD) is a lung complication of common variable immunodeficiency disorders (CVID). It is seen in approximately 15% of patients with CVID. It has been defined histologically as the presence of (non-caseating) granuloma and lymphoproliferation in the lung. However, as GLILD is often associated with other auto-immune features such as splenomegaly, adenopathy and cytopenias, a definition based on abnormalities on lung imaging (CT scan) together with evidence of granulomatous inflammation elsewhere has also been employed.

Although infections and complications of infection such as bronchiectasis are more common complications of CVID in the lung, the presence of immune manifestations including GLILD is important because this has been associated with greater risk of death.

In general, as a rare complication of a rare disease, the condition remains incompletely understood, and there is real need for further research in the area.

Feeding and swallowing can become difficult for people with A-T as they get older. Feeding refers to all aspects of eating and drinking, including getting food and liquids to the mouth; swallowing refers to ingestion or what happens after food or liquids enter the mouth. Primary goals for feeding and swallowing are safe, adequate, and enjoyable mealtimes.

Involuntary movements may make feeding difficult or messy and may excessively prolong mealtimes. It may be easier to finger feed than use utensils (e.g., spoon or fork). For liquids, it is often easier to drink from a closed container with a straw than from an open cup. Caregivers may need to provide foods or liquids so that self-feeding is possible, or they may need to feed the person with A-T. In general, meals should be completed within approximately 30 minutes. Longer meals may be stressful, interfere with other daily activities, and limit the intake of necessary liquids and nutrients.

If swallowing problems (dysphagia) occur, they typically present during the second decade of life. Dysphagia is common because of the neurological changes that interfere with coordination of mouth and pharynx (throat) movements that are needed for safe and efficient swallowing. Coordination problems involving the mouth may make chewing difficult and increase the duration of meals. Problems involving the pharynx may cause liquid, food, and saliva to be inhaled into the airway (aspiration). People with dysphagia may not cough when they aspirate (silent aspiration). Swallowing problems and especially swallowing problems with silent aspiration may cause lung problems due to inability to cough and clear food and liquids from the airway.

- Warning signs of a swallowing problem

- Choking or coughing when eating or drinking

- Poor weight gain (during ages of expected growth) or weight loss at any age

- Excessive drooling

- Mealtimes longer than 40 – 45 minutes, on a regular basis

- Foods or drinks previously enjoyed are now refused or difficult

- Chewing problems

- Increase in the frequency or duration of breathing or respiratory problems

- Increase in lung infections

Chronic lung disease develops in more than 25% of people with A-T. Three major types of lung disease can develop: (1) recurrent and chronic sinopulmonary infections; (2) lung disease caused by ineffective cough, swallowing dysfunction, and impaired airway clearance; and (3) restrictive interstitial lung disease. It is common for individuals with A-T to have more than one of these lung conditions. Chronic lung disease can occur because of recurrent lung infections due to immunodeficiency. Individuals with this problem are at risk of developing bronchiectasis, a condition in which bronchial tubes are permanently damaged, resulting in recurrent lower airway infections. Gamma globulin for people with antibody deficiency and/or chronic antibiotic treatment may reduce the problems of infection. Other individuals with A-T have difficulty with taking deep breaths and may have an ineffective cough, making it difficult to clear oral and bronchial secretions. This can lead to prolonged respiratory symptoms following common viral respiratory illnesses. Techniques that allow clearance of mucus can be helpful in some individuals during respiratory illnesses. Some people will develop swallowing problems as they age, increasing their risk of aspiration pneumonia. Recurrent injury to the lungs caused by chronic infections or aspiration may cause lung fibrosis and scarring. This process may be enhanced by inadequate tissue repair in ATM-deficient cells. A small number of individuals develop interstitial lung disease. They have decreased pulmonary reserve, trouble breathing, a need for supplemental oxygen and chronic cough in the absence of lung infections. They may respond to systemic steroid treatment or other drugs to reduce inflammation.

Lung function tests (spirometry) should be performed at least annually in children old enough to perform them, influenza and pneumococcal vaccines given to eligible individuals, and sinopulmonary infections treated aggressively to limit the development of chronic lung disease.

Central hypoventilation syndrome (CHS) is a respiratory disorder that results in respiratory arrest during sleep. CHS can either be congenital (CCHS) or acquired (ACHS) later in life. It is fatal if untreated. It is also known as Ondine's curse.

ACHS can develop as a result of severe injury or trauma to the brain or brainstem. Congenital cases are very rare and involve a failure of autonomic control of breathing. In 2006, there were only about 200 known cases worldwide. As of 2008, only 1000 total cases were known. The diagnosis may be delayed because of variations in the severity of the manifestations or lack of awareness in the medical community, particularly in milder cases. However, as there have been cases where asymptomatic family members also were found to have CCHS, it may be that these figures only reflect those found to require mechanical ventilation. In all cases, episodes of apnea occur in sleep, but in a few patients, at the most severe end of the spectrum, apnea also occurs while awake.

Although rare, cases of long-term untreated CCHS have been reported and are termed late onset CCHS (LO-CCHS). Cases that go undiagnosed until later life and middle age, although the symptoms are usually obvious in retrospect. There have, however, even been cases of LO-CCHS where family members found to have it have been asymptomatic. Again, lack of awareness in the medical community may cause such a delay. CCHS susceptibility is not known to be affected by gender.

CHS is associated with respiratory arrests during sleep and, in some cases, to neuroblastoma (tumors of the sympathetic ganglia), Hirschsprung disease (partial agenesis of the enteric nervous system), dysphagia (difficulty swallowing) and anomalies of the pupilla. Other symptoms include darkening of skin color from inadequate amounts of oxygen, drowsiness, fatigue, headaches, and an inability to sleep at night. Those suffering from Ondine's curse also have a sensitivity to sedatives and narcotics, which makes respiration even more difficult. A low concentration of oxygen in the red blood cells also may cause hypoxia-induced pulmonary vasoconstriction and pulmonary hypertension, culminating in cor pulmonale or a failure of the right side of the heart. Associated complications may also include gastro-esophageal reflux, ophthalmologic issues, seizures, recurrent pneumonia, developmental delays, learning disabilities and episodes of fainting and temperature disregulation.

Coughing and rattling are common, most severe in young, such as broilers, and rapidly spreading in chickens confined or at proximity. Morbidity is 100% in non-vaccinated flocks. Mortality varies according to the virus strain (up to 60% in non-vaccinated flocks). Respiratory signs will subdue within two weeks. However, for some strains, a kidney infection may follow, causing mortality by toxemia. Younger chickens may die of tracheal occlusion by mucus (lower end) or by kidney failure. The infection may prolong in the cecal tonsils.

In laying hens, there can be transient respiratory signs, but mortality may be negligible. However, egg production drops sharply. A great percentage of produced eggs are misshapen and discolored. Many laid eggs have a thin or soft shell and poor albumen (watery), and are not marketable or proper for incubation. Normally-colored eggs, indicative of normal shells for instance in brown chickens, have a normal hatchability.

Egg yield curve may never return to normal. Milder strains may allow normal production after around eight weeks.

Although symptoms can vary greatly between affected individuals, even those within the same family, symptoms normally begin in infancy and are typically a result of thickening skin and mucous membranes. The first symptom is often a weak cry or a hoarse voice due to a thickening of the vocal cords. The hoarse voice can be one of the most striking clinical manifestations of the disease. Lesions and scars also appear on the skin, usually the face and the distal parts of the limbs. This is often the result of poor wound healing and the scarring continues to increase as the patient ages, leaving the skin with a waxy appearance. Skin may be easily damaged as a result of only a minor trauma or injury, leaving many blisters and additional scars. The skin is also usually very dry and wrinkly. White or yellow infiltrates form on the lips, buccal mucosa, tonsils, uvula, epiglottis and frenulum of the tongue. This can lead to upper respiratory tract infection and sometimes requires tracheostomy to relieve the symptom. Too much thickening of the frenulum can restrict tongue movement and may result in speech impediments. Beading of the papules around the eyelids is a very common symptom and is often used as part of a diagnosis of the disease. Some other dermatological symptoms that are sometimes seen but less common include hair loss, parotitis and other dental abnormalities, corneal ulceration, and focal degeneration of the macula.

Urbach–Wiethe disease is characterized by both neurological and dermatological symptoms.

The variable presentation of ROHHAD includes the following main symptoms:

- Hyperphagia and obesity by age of 10 years - (median age 3 years);

- Respiratory Manifestations:

- Alveolar Hypoventilation (median onset age 6.2 years);

- Cardiorespiratory arrest;

- Reduced Carbon Dioxide Ventilatory Response;

- Obstructive sleep apnea.

- Thermal or other hypothalamic dysregulations, with autonomic dysregulation by median age 3.6 years:

- Failed Growth Hormone Stimulation;

- Adipsic hypernatremia (inability to feel thirst to keep normal hydration);

- Hypernatremia;

- Hyperprolactinemia;

- Hyperphagia;

- Diabetes insipidus;

- Ophthalmologic Manifestations;

- Thermal Dysregulation;

- Gastrointestinal dysmotility;

- Altered Perception of Pain;

- Altered Sweating;

- Cold Hands and Feet.

- Neurobehavioral disorders;

- Tumors of neural crest origin.

Clinically overlapping cases exist because CCHS phenotype can also include autonomic nervous system dysregulation, or tumors of neural crest origin.

Avian infectious bronchitis (IB) is an acute and highly contagious respiratory disease of chickens. The disease is caused by avian infectious bronchitis virus (IBV), a coronavirus, and characterized by respiratory signs including gasping, coughing, sneezing, tracheal rales, and nasal discharge. In young chickens, severe respiratory distress may occur. In layers, respiratory distress, nephritis, decrease in egg production, and loss of internal (watery egg white) and external (fragile, soft, irregular or rough shells, shell-less) egg quality are reported.

Jeune syndrome is a rare genetic disorder that affects the way a child’s cartilage and bones develop. It begins before the child is born. Jeune syndrome affects the child's rib cage, pelvis, arms and legs.

Usually, problems with the rib cage cause the most serious health problems for children with Jeune syndrome. Their rib cages (thorax) are smaller and narrower than usual. This can keep the child's lungs from developing fully or expanding when the child inhales. The child may breathe rapidly and shallowly. They may have trouble breathing when they have an upper or lower respiratory infection, like pneumonia.

Breathing trouble can range from mild to severe. In some children, it is not noticeable, aside from fast breathing. In most children, breathing problems are serious. About 60% to 70% of children with this condition die from respiratory failure as babies or young children.

Children with Jeune syndrome who survive often develop problems with their kidneys, another serious feature of Jeune syndrome. Over time they may experience renal failure.

As a result, few children with Jeune syndrome live into their teen years.

Children with Jeune syndrome have a form of dwarfism. They are short in stature, and their arms and legs are shorter than most people’s.

Another name for Jeune syndrome is asphyxiating thoracic dystrophy. This diagnosis is grouped with other chest problems called thoracic insufficiency syndrome (TIS).

Clinically, PASLI disease is characterized by recurrent sinopulmonary infections that can lead to progressive airway damage. Patients also suffer from lymphoproliferation (large lymph nodes and spleen), chronic viremia due to EBV or CMV, distinctive lymphoid nodules at mucosal surfaces, autoimmune cytopenias, and EBV-driven B cell lymphoma. Importantly, the clinical presentations and disease courses are variable with some individuals severely affected, whereas others show little manifestation of disease. This “variable expressivity,” even within the same family, can be striking and may be explained by differences in lifestyle, exposure to pathogens, treatment efficacy, or other genetic modifiers.