The typical symptoms of UIP are progressive shortness of breath and cough for a period of months. In some patients, UIP is diagnosed only when a more acute disease supervenes and brings the patient to medical attention.

The cause of the scarring in UIP may be known (less commonly) or unknown (more commonly). Since the medical term for conditions of unknown cause is "idiopathic", the clinical term for UIP of unknown cause is idiopathic pulmonary fibrosis (IPF). Examples of known causes of UIP include systemic sclerosis/scleroderma, rheumatoid arthritis, asbestosis, and prolonged use of medications such as nitrofurantoin or amiodarone.

Patients with subacute HP gradually develop a productive cough, dyspnea, fatigue, anorexia, weight loss, and pleurisy. Symptoms are similar to the acute form of the disease, but are less severe and last longer. On chest radiographs, micronodular or reticular opacities are most prominent in mid-to-lower lung zones. Findings may be present in patients who have experienced repeated acute attacks.

The subacute, or intermittent, form produces more well-formed noncaseating granulomas, bronchiolitis with or without organizing pneumonia, and interstitial fibrosis.

In the acute form of HP, symptoms may develop 4–6 hours following heavy exposure to the provoking antigen. Symptoms include fever, chills, malaise, cough, chest tightness, dyspnea, rash, swelling and headache. Symptoms resolve within 12 hours to several days upon cessation of exposure.

Acute HP is characterized by poorly formed noncaseating interstitial granulomas and mononuclear cell infiltration in a peribronchial distribution with prominent giant cells.

On chest radiographs, a diffuse micronodular interstitial pattern (at times with ground-glass density in the lower and middle lung zones) may be observed. Findings are normal in approximately 10% of patients." In high-resolution CT scans, ground-glass opacities or diffusely increased radiodensities are present. Pulmonary function tests show reduced diffusion capacity of lungs for carbon monoxide (DLCO). Many patients have hypoxemia at rest, and all patients desaturate with exercise. Extrinsic allergic alveolitis may eventually lead to Interstitial lung disease.

Initially, the disease appears as alveolitis, and then progresses to emphysema.

Patients may develop pneumothorax (collapsed lung).

Almost all patients have clinically diagnosed asthma, and present with wheezing (usually episodic in nature), coughing, shortness of breath and exercise intolerance (especially in patients with cystic fibrosis). Moderate and severe cases have symptoms suggestive of bronchiectasis, in particular thick sputum production (often containing brown mucus plugs), as well as symptoms mirroring recurrent infection such as pleuritic chest pain and fever. Patients with asthma and symptoms of ongoing infection, who do not respond to antibiotic treatment, should be suspected of ABPA.

Aspergillosis is an infection caused by the fungus "Aspergillus". Aspergillosis describes a large number of diseases involving both infection and growth of fungus as well as allergic responses. Aspergillosis can occur in a variety of organs, both in humans and animals.

The most common sites of infection are the respiratory apparatus (lungs, sinuses) and these infections can be:

- Invasive (e.g. – IPA)

- Non-invasive (e.g. Allergic Pulmonary Aspergillosis - ABPA)

- Chronic pulmonary and aspergilloma (e.g. chronic cavitary, semi-invasive)

- Severe asthma with fungal sensitisation (SAFS)

Chronic pulmonary aspergillosis (CPA) is a long-term aspergillus infection of the lung and "Aspergillus fumigatus" is almost always the species responsible for this illness. Patients fall into several groups as listed below.

- Those with an aspergilloma which is a ball of fungus found in a single lung cavity - which may improve or disappear, or change very little over a few years.

- Aspergillus nodule

- Chronic cavitary pulmonary aspergillosis (CCPA) where cavities are present in the lungs, but not necessarily with a fungal ball (aspergilloma).

- Chronic fibrosing pulmonary aspergillosis this may develop where pulmonary aspergillosis remains untreated and chronic scarring of the lungs occurs. Unfortunately scarring of the lungs does not improve.

Most patients with CPA have or have had an underlying lung disease. The most common diseases include tuberculosis, atypical mycobacterium infection, stage III fibrocystic pulmonary sarcoidosis, ABPA, lung cancer, COPD and emphysema, asthma and silicosis.

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 specific criteria for diagnosis of CPA are:

Chest X-rays showing one or more lung cavities. There may be a fungal ball present or not.

Symptoms lasting more than 3 months, usually including weight loss, fatigue, cough, coughing blood (haemoptysis) and breathlessness

A blood test or tissue fluid test positive for Aspergillus species

Aspergilloma

An aspergilloma is a fungal mass caused by a fungal infection with Aspergillus species that grows in either scarred lungs or in a pre-existing lung cavity, which may have been caused by a previous infection. Patients with a previous history of tuberculosis, sarcoidosis, cystic fibrosis or other lung disease are most susceptible to an aspergilloma. Aspergillomas may have no specific symptoms but in many patients there is some coughing up of blood called haemoptysis - this may be infrequent and in small quantity, but can be severe and then it requires urgent medical help.

Tests used to diagnose an aspergilloma may include:

- Chest X-ray

- Chest CT

- Sputum culture

- Bronchoscopy or bronchoscopy with lavage (BAL)

- Serum precipitins for aspergillus (blood test to detect antibodies to aspergillus)

Almost all aspergillomas are caused by "Aspergillus fumigatus". In diabetic patients it may be caused by "Aspergillus niger". It is very rarely caused by "Aspergillus flavus", "Aspergillus oryzae", "Aspergillus terreus" or "Aspergillus nidulans".

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.

People with aspergillomata typically remain asymptomatic until the condition is fairly advanced; in some cases even for decades. Diagnosis is often made as a result of an incidental finding on a chest X-ray or CT scan that may be performed as part of the workup for another unrelated condition. However, a small percentage of aspergillomata invade into a blood vessel which can result in bleeding. Thus, the most common symptom of associated with aspergillomata is coughing up blood (hemoptysis). This may result in life-threatening hemorrhage, though the amount of blood lost is usually inconsequential.

Aspergillomata can also form in other organs. They can form abscesses in solid organs such as the brain or kidney, usually in people who are immunocompromised. They can also develop within body cavities such as the sphenoid or paranasal sinuses, the ear canal, and rarely on surfaces such as heart valves.

Lycoperdonosis is a respiratory disease caused by the inhalation of large amounts of spores from mature puffballs. It is classified as a hypersensitivity pneumonitis (also called extrinsic allergic alveolitis)—an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled natural dusts. It is one of several types of hypersensitivity pneumonitis caused by different agents that have similar clinical features. Typical progression of the disease includes symptoms of a cold hours after spore inhalation, followed by nausea, rapid pulse, crepitant rales (a sound like that made by rubbing hairs between the fingers, heard at the end of inhalation), and dyspnea. Chest radiographs reveal the presence of nodules in the lungs. The early symptoms presented in combination with pulmonary abnormalities apparent on chest radiographs may lead to misdiagnosis of the disease as tuberculosis, histiocytosis, or pneumonia caused by "Pneumocystis carinii". Lycoperdonosis is generally treated with corticosteroids, which decrease the inflammatory response; these are sometimes given in conjunction with antimicrobials.

The disease was first described in the medical literature in 1967 by R.D. Strand and colleagues in the "New England Journal of Medicine". In 1976, a 4-year-old was reported developing the disease in Norway after purposely inhaling a large quantity of "Lycoperdon" spores to stop a nosebleed. "Lycoperdon" species are sometimes used in folk medicine in the belief that their spores have haemostatic properties. A 1997 case report discussed several instances of teenagers inhaling the spores. In one severe case, the individual inhaled enough spores so as to be able to blow them out of his mouth. He underwent bronchoscopy and then had to be on life support before recovering in about four weeks. In another instance, a teenager spent 18 days in a coma, had portions of his lung removed, and suffered severe liver damage. In Wisconsin, eight teenagers who inhaled spores at a party presented clinical symptoms such as cough, fever, shortness of breath, myalgia, and fatigue within a week. Five of the eight required hospitalization; of these, two required intubation to assist in breathing. The disease is rare, possibly because of the large quantity of spores that need to be inhaled for clinical effects to occur. Lycoperdonosis also occurs in dogs; in the few reported cases, the animals had been playing or digging in areas known to contain puffballs. Known species of puffballs implicated in the etiology of the published cases include the widespread "Lycoperdon perlatum" (the "devil's snuff-box", "L. gemmatum") and "Calvatia gigantea", both of the Lycoperdaceae family.

Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterised by an exaggerated response of the immune system (a hypersensitivity response) to the fungus "Aspergillus" (most commonly "Aspergillus fumigatus"). It occurs most often in patients 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.

ABPA causes airway inflammation, leading to bronchiectasis—a condition marked by abnormal dilation of the airways. Left untreated, the immune system and fungal spores can damage sensitive lung tissues and lead to scarring.

The exact criteria for the diagnosis of ABPA are not agreed upon. Chest X-rays and CT scans, raised blood levels of IgE and eosinophils, immunological tests for "Aspergillus" together with sputum staining and sputum cultures can be useful. Treatment consists of corticosteroids and antifungal medications.

An aspergilloma, also known as a "mycetoma or fungus ball"', is a clump of mold which exists in a body cavity such as a paranasal sinus or an organ such as the lung. By definition, it is caused by fungi of the genus "Aspergillus".

Bauxite pneumoconiosis, also known as Shaver's disease, corundum smelter's lung, bauxite lung or bauxite smelters' disease, is a progressive form of pneumoconiosis usually caused by occupational exposure to bauxite fumes which contain aluminium and silica particulates.

It is typically seen in workers involved in the smelting of bauxite to produce corundum.

Clinically, the most serious and immediate complication is acute respiratory distress syndrome (ARDS), which usually occurs within 24 h. Those with significant lower airway involvement may develop bacterial infection. Importantly, victims suffering body surface burn and smoke inhalation are the most susceptible. Thermal injury combined with inhalation injury compromises pulmonary function, producing microvascular hyperpermeability that leads to a significant increase in lung lymph flow and pulmonary edema. The terrorist attack on the World Trade Center on September 11, 2001 left many people with impaired lung function. A study of firefighters and EMS workers enrolled in the FDNY WTC Medical Monitoring and Treatment Program, whose lung function was tested prior to 9/11, documented a steep decline in lung function in the first year after 9/11. A new study that includes a thousand additional workers shows that the declines have persisted over time. Prior to 9/11, 3% of firefighters had below-normal lung function, one year after 9/11 nearly 19% did, and six years later it stabilized at 13%. Ten to 14 days after acute exposure to some agents (e.g. ammonia, nitrogen oxides, sulfur dioxide, mercury), some patients develop bronchiolitis obliterans progressing to ARDS. Bronchiolitis obliterans with organized pneumonia can ensue when granulation tissue accumulates in the terminal airways and alveolar ducts during the body's reparative process. A minority of these patients develop late pulmonary fibrosis. Also at enhanced risk are persons with co-morbidities. Several studies report that both aged persons and smokers are especially vulnerable to the adverse effects of inhalation injury.

A fungus ball in the lungs may cause no symptoms and may be discovered only with a chest X-ray, or it may cause repeated coughing up of blood, chest pain, and occasionally severe, even fatal, bleeding. A rapidly invasive "Aspergillus" infection in the lungs often causes cough, fever, chest pain, and difficulty breathing.

Poorly controlled aspergillosis can disseminate through the blood stream to cause widespread organ damage. Symptoms include fever, chills, shock, delirium, seizures and blood clots. The person may develop kidney failure, liver failure (causing jaundice), and breathing difficulties. Death can occur quickly.

Aspergillosis of the ear canal causes itching and occasionally pain. Fluid draining overnight from the ear may leave a stain on the pillow. Aspergillosis of the sinuses causes a feeling of congestion and sometimes pain or discharge. It can extend beyond the sinuses.

In addition to the symptoms, an X-ray or computerised tomography (CT) scan of the infected area provides clues for making the diagnosis. Whenever possible, a doctor sends a sample of infected material to a laboratory to confirm identification of the fungus.

Acute inhalation injury may result from frequent and widespread use of household cleaning agents and industrial gases (including chlorine and ammonia). 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.

Depending on the type and amount of irritant gas inhaled, victims can experience symptoms ranging from minor respiratory discomfort to acute airway and lung injury and even death. A common response cascade to a variety of irritant gases includes inflammation, edema and epithelial sloughing, which if left untreated can result in scar formation and pulmonary and airway remodeling. Currently, mechanical ventilation remains the therapeutic mainstay for pulmonary dysfunction following acute inhalation injury.

Aspergillosis is the name given to a wide variety of diseases caused by infection by fungi of the genus "Aspergillus". The majority of cases occur in people with underlying illnesses such as tuberculosis or chronic obstructive pulmonary disease (COPD), but with otherwise healthy immune systems. Most commonly, aspergillosis occurs in the form of chronic pulmonary aspergillosis (CPA), aspergilloma or allergic bronchopulmonary aspergillosis (ABPA). Some forms are intertwined; for example ABPA and simple aspergilloma can progress to CPA.

Other, non-invasive manifestations include fungal sinusitis (both allergic in nature and with established fungal balls), otomycosis (ear infection), keratitis (eye infection) and onychomycosis (nail infection). In most instances these are less severe, and curable with effective antifungal treatment.

People with deficient immune systems—such as patients undergoing hematopoietic stem cell transplantation, chemotherapy for leukaemia, or AIDS—are at risk of more disseminated disease. Acute invasive aspergillosis occurs when the immune system fails to prevent "Aspergillus" spores from entering the bloodstream via the lungs. Without the body mounting an effective immune response, fungal cells are free to disseminate throughout the body and can infect major organs such as the heart and kidneys.

The most frequently identified pathogen is "Aspergillus fumigatus"—a ubiquitous organism that is capable of living under extensive environmental stress. It is estimated that most humans inhale thousands of "Aspergillus" spores daily, but they do not affect most people’s health due to effective immune responses. Taken together, the major chronic, invasive and allergic forms of aspergillosis account for around 600,000 deaths annually worldwide.

Suberosis, also known as corkhandler's disease or corkworker's lung, is a type of hypersensitivity pneumonitis usually caused by the fungus "Penicillium glabrum" (formerly called "Penicillum frequentans") from exposure to moldy cork dust. "Chrysonilia sitophilia", "Aspergillus fumigatus", uncontaminated cork dust, and "Mucor macedo" may also have significant roles in the pathogenesis of the disease.

Fungal pneumonia can be diagnosed in a number of ways. The simplest and cheapest method is to culture the fungus from a patient's respiratory fluids. However, such tests are not only insensitive but take time to develop which is a major drawback because studies have shown that slow diagnosis of fungal pneumonia is linked to high mortality. Microscopy is another method but is also slow and imprecise. Supplementing these classical methods is the detection of antigens. This technique is significantly faster but can be less sensitive and specific than the classical methods.

A molecular test based on quantitative PCR is also available from Myconostica. Relying on DNA detection, this is the most sensitive and specific test available for fungi but it is limited to detecting only pneumocystis jirovecii and aspergillus.

Fungal pneumonia is an infection of the lungs by fungi. It can be caused by either endemic or opportunistic fungi or a combination of both. Case mortality in fungal pneumonias can be as high as 90% in immunocompromised patients, though immunocompetent patients generally respond well to anti-fungal therapy.

Cork is often harvested from the cork oak ("Quercus suber") and stored in slabs in a hot and humid environment until covered in mold. Cork workers may be exposed to organic dusts in this process, leading to this disease.

Symptoms arise 4–12 hours after exposure to an organic dust, and generally last from one to five days. Common generalised symptoms include fever over 38 °C, chills, myalgia and malaise. The most frequent respiratory symptoms are dyspnea and a dry cough, while a wheeze may be present less commonly. Headache, rhinitis, conjunctivitis and keratitis can also be present, and skin irritation may occur in those handling grain.

Respiratory function may worsen to the point where hypoxia occurs, and damage to the airways may lead to non-cardiogenic pulmonary edema one to three days post exposure.

Laboratory investigations may show a raised white cell (and specifically neutrophil) count, while a chest X-ray is often normal or shows minimal interstitial infiltration.

Organic dust toxic syndrome (ODTS) is a potentially severe flu-like syndrome originally described in farmers, mushroom workers, bird breeders and other persons occupationally exposed to dusty conditions.