An exacerbation (attack) of asthma is experienced as a worsening of asthma symptoms with breathlessness and cough (often worse at night). In acute severe asthma, breathlessness may be so severe that it is impossible to speak more than a few words (inability to complete sentences).

On examination, the respiratory rate may be elevated (more than 25 breaths per minute), and the heart rate may be rapid (110 beats per minute or faster). Reduced oxygen saturation levels (but above 92%) are often encountered. Examination of the lungs with a stethoscope may reveal reduced air entry and/or widespread wheeze. The peak expiratory flow can be measured at the bedside; in acute severe asthma the flow is less than 50% a person's normal or predicted flow.

Very severe acute asthma (termed "near-fatal" as there is an immediate risk to life) is characterised by a peak flow of less than 33% predicted, oxygen saturations below 92% or cyanosis (blue discoloration, usually of the lips), absence of audible breath sounds over the chest ("silent chest"), reduced respiratory effort and visible exhaustion or drowsiness. Irregularities in the heart beat and abnormal lowering of the blood pressure may be observed.

Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways).

Bronchial hyperresponsiveness can be assessed with a bronchial challenge test. This most often uses products like methacholine or histamine. These chemicals trigger bronchospasm in normal individuals as well, but people with bronchial hyperresponsiveness have a lower threshold.

Bronchial hyperresponsiveness is a hallmark of asthma but also occurs frequently in people suffering from chronic obstructive pulmonary disease (COPD). In the Lung Health Study, bronchial hyperresponsiveness was present in approximately two-thirds of patients with non-severe COPD, and this predicted lung function decline independently of other factors. In asthma it tends to be reversible with bronchodilator therapy, while this is not the case in COPD.

Bronchial hyperresponsiveness has been associated with gas cooking among subjects with the "GSTM1" null genotype.

Acute severe asthma is an acute exacerbation of asthma that does not respond to standard treatments of bronchodilators (inhalers) and corticosteroids. Symptoms include chest tightness, rapidly progressive dyspnea (shortness of breath), dry cough, use of accessory respiratory muscles, fast and/or labored breathing, and extreme wheezing. It is a life-threatening episode of airway obstruction and is considered a medical emergency. Complications include cardiac and/or respiratory arrest.

It is characterized histologically by smooth muscle hypertrophy and basement membrane thickening.

The clinical presentation of plastic bronchitis beyond expectoration of casts includes a productive cough, dyspnea, fever and wheezing. Focal wheezing is a characteristic, if not specific, physical examination finding. If the casts completely obstruct the airway, breath sounds will be decreased and dullness will be present with percussion. With partial obstruction, a “fan sound” or “flag flapping” sound can be heard during auscultation. Bronchial casts can sometimes fill the airways of almost an entire lung, and present as an acute, life-threatening emergency.

It might be expected that people with E.I.B. would present with shortness of breath, and/or an elevated respiratory rate and wheezing, consistent with an asthma attack. However, many will present with decreased stamina, or difficulty in recovering from exertion compared to team members, or paroxysmal coughing from an irritable airway. Similarly, examination may reveal wheezing and prolonged expiratory phase, or may be quite normal. Consequently, a potential for under-diagnosis exists. Measurement of airflow, such as peak expiratory flow rates, which can be done inexpensively on the track or sideline, may prove helpful.

Asthma is an obstructive lung disease where the bronchial tubes (airways) are extra sensitive (hyperresponsive). The airways become inflamed and produce excess mucus and the muscles around the airways tighten making the airways narrower. Asthma is usually triggered by breathing in things in the air such as dust or pollen that produce an allergic reaction. It may be triggered by other things such as an upper respiratory tract infection, cold air, exercise or smoke. Asthma is a common condition and affects over 300 million people around the world.

Asthma causes recurring episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning.

- Exercise-Induced Asthma — is common in asthmatics, especially after participation in outdoor activities in cold weather.

- Occupational Asthma — An estimated 2% to 5% of all asthma episodes may be caused by exposure to a specific sensitizing agent in the workplace.

- Nocturnal Asthma — is a characteristic problem in poorly controlled asthma and is reported by more than two thirds of sub-optimally treated patients.

A peak flow meter can record variations in the severity of asthma over time. Spirometry, a measurement of lung function, can provide an assessment of the severity, reversibility, and variability of airflow limitation, and help confirm the diagnosis of asthma.

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.

Fire breather’s pneumonia usually presents with certain non-specific symptoms, and may vary significantly among individuals. The most common symptoms include:

- Cough

- Dyspnea (shortness of breath)

- Chest pain

- Fever

- Weakness

- Hemoptysis (coughing up blood)

Acute pneumonitis typically begins asymptomatic, with a worsening of symptoms over the course of hours or days. Following aspiration of fuel, there is often a period of latency from 8–24 hours before the symptoms occur. Patients may not recall a specific instance of aspiration. Severe cases may lead to acute respiratory distress syndrome (ARDS).

Some people with bronchiectasis may have a cough productive of frequent green/yellow mucus (sputum), up to 240 ml (8 oz) daily. Bronchiectasis may also present with coughing up blood (hemoptysis) in the absence of sputum, called "dry bronchiectasis". Sputum production may also occur without coloration. People with bronchiectasis may have bad breath indicative of active infection. Frequent bronchial infections and breathlessness are two possible indicators of bronchiectasis.

Crepitations and expiratory rhonchi may be heard on auscultation. Nail clubbing is rare.

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 can be very mild to severe.

Bronchospasms appear as the feature of asthma, chronic bronchitis and anaphylaxis. Bronchospasms are a possible side effect of some drugs: pilocarpine (which is used to treat illness resulting from the ingestion of deadly nightshade, as well as other things), beta blockers (used to treat hypertension), a paradoxical result of using LABA drugs (to treat COPD) and other drugs. Bronchospasms can present as a sign of giardiasis.

Bronchospasms are one of several conditions associated with cold housing.

Some of the things that can cause bronchospasms are: consuming foods, taking medicines, allergic responses to insects, and fluctuating hormone levels, particularly in women.

A few of the more common allergens are foods such as eggs, milk, peanuts, walnuts, tree and other nuts, fish, especially shellfish, soy and wheat; insect bites and stings, especially bee stings; and other medicines, especially penicillin and its derivatives.

The overactivity of the bronchioles' muscle is a result of exposure to a stimulus which under normal circumstances would cause little or no response. The resulting constriction and inflammation causes a narrowing of the airways and an increase in mucus production; this reduces the amount of oxygen that is available to the individual causing breathlessness, coughing and hypoxia.

Bronchospasms are a serious potential complication of placing a breathing tube during general anesthesia. When the airways spasm or constrict in response to the irritating stimulus of the breathing tube, it is difficult to maintain the airway and the patient can become apneic.

Reactive airway disease is a group of conditions that include reversible airway narrowing due to an external stimulation. These conditions generally result in wheezing.

Conditions within this group include asthma, chronic obstructive pulmonary disease, and viral upper respiratory infections.

The term reactive airway disease may be used in pediatrics to describe an asthma-like syndrome in infants too young for diagnostic testing such as the bronchial challenge test. These infants may later be confirmed to have asthma following testing. The term is sometimes misused as a synonym for asthma.

Bronchospasm are caused by a number of reasons. Lower respiratory tract conditions such as asthma, chronic obstructive pulmonary disease (COPD), and emphysema can result in contraction of the airways. Other causes are side effects of topical decongestants such as oxymetazoline and phenylephrine. Both of these medications activate alpha-1 adrenergic receptors that result in smooth muscle constriction. Non-selective beta blockers are known to facilitate bronchospasm as well. Beta blockers bind into the β2 receptors and block the action of epinephrine and norepinephrine from binding to its receptors, causing shortness of breath.

Exercise-induced asthma, or E.I.A., occurs when the airways narrow as a result of exercise. The preferred term for this condition is exercise-induced bronchoconstriction (EIB); exercise does not cause asthma, but is frequently an asthma trigger.

The majority of PB cases are associated with an underlying disease. Several systemic illnesses have been associated with plastic bronchitis:

- Cardiac: constrictive pericarditis, congenital heart disease

- Pulmonary: asthma, allergic bronchopulmonary aspergillosis, aspergillosis, bronchiectasis, cystic fibrosis, tuberculosis, pneumonia, and bronchocentric granulomatosis

- Disorders of lymphatic drainage: lymphangiectasia, lymphangiomatosis

- Miscellaneous: acute chest syndrome/sickle cell disease, amyloidosis, rheumatoid arthritis, membranous colitis, inhaled irritants, neoplastic (lymphoma)

The most common form of plastic bronchitis follows cardiac surgery for congenital heart disease, especially the Fontan procedure. Systemic blood flow is diverted to pulmonary flow, elevating pressures in the pulmonary venous system, and promoting leaks of proteinaceous and lipid-rich fluids from the lymphatics into the bronchial tree.

Signs that consolidation may have occurred include:

- Expansion of the thorax on inspiration is reduced on the affected side

- Vocal fremitus is increased on the side with consolidation

- Percussion is dull in affected area

- Breath sounds are bronchial

- Possible medium, late, or pan-inspiratory crackles

- Vocal resonance is increased. Here, the patient's voice (or whisper, as in whispered pectoriloquy) can be heard more clearly when there is consolidation, as opposed to in the healthy lung where speech sounds muffled.

- A pleural rub may be present.

- A lower expected Pa02 than calculated in the alveolar gas equation

About 20% of DIPNECH patients are symptom free at the time they first present. The most common symptoms include:

- Chronic cough

- Shortness of breath or dyspnea when exercising or exerting one’s self

- Wheezing (less frequent)

- Hemoptysis (Infrequent)

Symptoms may be present for many years prior to diagnosis and are often ascribed to other lung conditions. Erroneous initial diagnoses of asthma or chronic obstructive pulmonary disease often are made in patients with DIPNECH.

Less than five years of exposure or a single exposure to a high-concentration agent can result in symptoms. Coughing, wheezing, nasal irritation, shortness of breath, and chest tightness are the most common symptoms, all of which worsen after work and improve during time away from work. Pre-existing asthma can be exacerbated by similar agents.

Cardiac asthma is a medical diagnosis of wheezing, coughing or shortness of breath due to congestive heart failure. It is known as cardiac asthma because the symptoms mimic ordinary asthma (bronchial asthma). One study found that patients with cardiac asthma represented one third of congestive heart failure in elderly patients.

Depending on severity, it may be classified as a medical emergency, as it can be a symptom of acute heart failure leading to the buildup of fluid in the lungs (pulmonary edema) as well as within and around the airways.

The distinction between bronchial asthma and cardiac asthma is especially important because some treatments for bronchial asthma, including inhalers, may worsen cardiac asthma or cause severe heart arrhythmias.

Bronchial asthma, in contrast, is caused by the inflammation and narrowing of pulmonary airways, causing the characteristic breathing difficulties. Bronchial asthma has nothing to do with fluid in the lungs or heart disease, or even the heart failure associated with cardiac asthma.

Bronchiectasis has both congenital and acquired causes, with the latter more frequent. Cystic fibrosis is a cause in up to half of cases. The cause in 10-50% of those without cystic fibrosis is unknown; bronchiectasis without CF is known as non-CF bronchiectasis (NCBE).

Occupational asthma is an occupational lung disease and a type of asthma. Like other types of asthma, it is characterized by airway inflammation, reversible airways obstruction, and bronchospasm, but it is caused by something in the workplace environment.

Symptoms include shortness of breath, tightness of the chest, nasal irritation, coughing and wheezing. The first person to use it in reference to a medical condition was Hippocrates, and he believed that tailors, anglers and metalworkers were more likely to be affected by the disease. Although much research has been done since, the inflammatory component of asthma was recognized only in the 1960s.

Hypersensitivity pneumonitis is a related condition, with many occupational examples (e.g. flock worker's lung, farmer's lung, and indium lung). However, although overlapping in many cases, hypersensitivity pneumonitis may be distinguished from occupational asthma in that it isn't restricted to only occupational exposure, and involves type III hypersensitivity and type IV hypersensitivity rather than the type I hypersensitivity of asthma. Also, unlike asthma, hypersensitivity pneumonitis targets lung alveoli rather than bronchi.

Bronchiolitis obliterans is a lung disease characterized by fixed airway obstruction. Inflammation and scarring occur in the airways of the lung, resulting in severe shortness of breath and dry cough.

FEV1 (forced expiratory volume in 1 second) should be above 80% of predicted values to be considered normal. Bronchiolitis obliterans reduces this to between 16% and 21%.

Symptoms include dry cough, shortness of breath and wheezing.

The symptoms can start gradually, or severe symptoms can occur suddenly.

Bronchomalacia can best be described as a birth defect of the bronchus in the respiratory tract. Congenital malacia of the large airways is one of the few causes of irreversible airways obstruction in children, with symptoms varying from recurrent wheeze and recurrent lower airways infections to severe dyspnea and respiratory insufficiency. It may also be acquired later in life due to chronic or recurring inflammation resulting from infection or other airway disease.

The pneumonia presents as a foreign body reaction causing cough, dyspnoea, and often fever. Haemoptysis has also been reported.

A pulmonary consolidation is a region of (normally compressible) lung tissue that has filled with liquid, a condition marked by induration (swelling or hardening of normally soft tissue) of a normally aerated lung. It is considered a radiologic sign. Consolidation occurs through accumulation of inflammatory cellular exudate in the alveoli and adjoining ducts. Simply, it is defined as alveolar space that contains liquid instead of gas. The liquid can be pulmonary edema, inflammatory exudate, pus, inhaled water, or blood (from bronchial tree or hemorrhage from a pulmonary artery). It must be present to diagnose pneumonia: the signs of lobar pneumonia are characteristic and clinically referred to as consolidation.

Fire breather's pneumonia, also known as fire breather's lung or fire-eater's lung, is a distinct type of exogenous—that is, originating outside the body—lipoid pneumonia (chemical pneumonitis) that results from inhalation or aspiration of hydrocarbons of different types, such as lamp oil. Accidental inhalation of hydrocarbon fuels can occur during fire breathing, fire eating, or other fire performance, and may lead to pneumonitis.

Symptoms can vary significantly among individuals, ranging from asymptomatic to a severe, life-threatening disease. Onset usually occurs within hours, though symptoms may not appear for several days. Lipoid pneumonia is a rare condition, but is an occupational hazard of fire performers.