Overview
A general term for a variety of diseases that occur in the lungs. Common symptoms include cough, sputum, shortness of breath, chest tightness, dyspnea, hemoptysis, fever, etc. Causes are complex and include infections, smoking, genetics, the environment, immunity, etc. and may require medications, surgeries, radiation therapy, chemotherapy, etc.
Definition
Lung disease is a general term for all diseases that occur in the lungs, including structural and/or functional changes in the lungs due to various causes.
It can cause a series of associated clinical manifestations such as cough, sputum, hemoptysis, shortness of breath, wheezing, dyspnea, fever, chest pain, and fatigue.
The lungs are composed of alveoli, intrapulmonary bronchioles, blood vessels, nerves, and lymphatic tissues, and the outer surface is covered by a dirty pleura.
Classification
There are many types of lung diseases, which can be categorized into the following three groups according to the different anatomical structures in which the lesions occur.
Parenchymal lung diseases: diseases occurring in all levels of bronchi and terminal fine bronchi and the alveolar structures to which they belong, such as various types of pneumonias, lung tumors, lung abscesses and so on.
Interstitial lung diseases: a group of diffuse lung diseases mainly involving the interstitial and alveolar cavities of the lungs, including idiopathic pulmonary fibrosis, tuberculosis, pneumoconiosis and so on.
Pulmonary vascular diseases: including pulmonary embolism, pulmonary hypertension, pulmonary veno-occlusive disease, etc.
Morbidity
Lung disease is the number one systemic disease in the country, and because it encompasses a wide range of diseases, there are no precise morbidity statistics on lung disease. Compared to other systemic diseases, lung disease has a high morbidity and mortality rate, and has long been the number 1 cumulative hospitalization [2-3].
Lung disease can occur in all population groups.
Etiology
The etiology is complex, sometimes a single etiologic factor causes morbidity, sometimes multiple etiologic factors lead to morbidity.
Causes
Infectious factors
Bacterial infections: e.g. Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus aureus hemolyticus, Klebsiella pneumoniae, Haemophilus influenzae, Pseudomonas aeruginosa pneumoniae and Acinetobacter baumannii.
Atypical pathogens: e.g. Mycoplasma, Chlamydia, Legionella, etc.
Viral infections: e.g. coronavirus, influenza virus, adenovirus, respiratory syncytial virus, measles virus, cytomegalovirus, herpes simplex virus, etc.
Fungal infections: e.g. Candida, Aspergillus, Cryptococcus, Pneumocystis, Trichoderma, etc.
Other pathogens: e.g., rickettsiae (e.g., Rickettsia q fever), toxoplasma gondii (e.g., Toxoplasma gondii), and parasites (e.g., lungworm, schistosoma, schistosoma pneumoniae).
Non-infectious factors
Smoking
Smoking is a very important pathogenetic factor.
The prevalence of chronic bronchitis in smokers is two to eight times higher than in nonsmokers.
Long-term smokers have a significantly increased risk of developing pneumonia.
Smoking is also the most common cause of lung cancer, and about 85% of lung cancer patients have a history of smoking [4].
Environmental factors
Exposure to allergens: e.g. dust mites, domestic pets, pollen, paint, fish, shrimp, eggs, milk, drugs (e.g. aspirin, antibiotics), etc.
Occupational exposure: especially long-term mining, quarrying, pit operations and production operations in quartz powder factories, glass factories, refractory material factories, ceramic factories.
Atmospheric pollution: such as industrial exhaust in the city, automobile exhaust, and a large amount of dust in the air.
Genetic factors
Congenital and hereditary bronchial insufficiency or abnormality, cartilage defects, etc.
The risk of lung cancer in relatives in family history of early lung cancer is elevated two times [5].
Immune abnormalities
Immunocompromised: e.g., AIDS, long-term immunosuppressive therapy predisposes to lung disease.
Autoimmune diseases: e.g., systemic lupus erythematosus, rheumatoid arthritis, polyarteritis nodosa, desiccation syndrome, and dermatomyositis multiforme can involve the lungs, leading to connective tissue disease-associated interstitial lung disease.
Others
Radiation injury can cause radiation pneumonitis.
Pharmacologic lung injuries, such as those caused by long-term use of drugs such as furotoxin and amiodarone [6].
Predisposing factors
Rain, cold, sudden changes in climate, and overwork can reduce the local defense function of the respiratory tract, leading to rapid reproduction of pre-existing viruses or bacteria, inducing infectious lung disease, or aggravating the symptoms of pre-existing lung disease.
High risk factors
High age, low immune function, long-term bed rest, repeated choking and coughing, upper respiratory tract infections, etc. are all high-risk factors for this disease.
Symptoms
Main symptoms
Localized symptoms of the respiratory system are the most common in lung disease, mainly cough, sputum, hemoptysis, dyspnea and chest pain.
Cough
It can be paroxysmal irritating dry cough, and in severe cases, the cough is persistent and severe, which may affect sleep, and can be seen in asthma, mycoplasma pneumonia, primary pulmonary hypertension, etc.
Coughing up sputum
The color of sputum varies according to the pathogenic bacteria and is also affected by bleeding.
For example, a large amount of yellow pus sputum is common in lung abscess or bronchiectasis, rusty sputum may be Streptococcus pneumoniae infection, reddish-brown jellied sputum may be Klebsiella pneumoniae infection, coughing up pink thin foamy sputum may be pulmonary oedema, pulmonary amoebiasis is coffee-like sputum, and schistosomiasis is jam-like sputum [7].
Dyspnea.
When lung lesions are severe, it will lead to dyspnea, which is characterized by dyspnea, chest tightness, shallow fast breathing, etc. Severe hypoxia can lead to bruising of lips and nails, or even death.
It can be seen in severe pneumonia, pneumoconiosis, lung cancer and many other lung diseases.
Hemoptysis
Hemoptysis can be manifested as blood in sputum or fresh blood.
Blood in sputum is a common symptom of tuberculosis and lung cancer.
Fresh blood is mostly seen in bronchiectasis, but also in tuberculosis, pneumonia and pulmonary thromboembolism.
Chest pain
It can be manifested as severe pain or slight hidden pain.
It can be seen in lung inflammation, lung cancer, pulmonary embolism and other lung diseases.
Other symptoms
When the disease is severe, it may show other systemic symptoms or systemic symptoms, such as fever, chills, chills, malaise, loss of appetite, muscle aches, weight loss, etc.
Complications
When the lung disease is more serious or not treated timely, it can cause a variety of complications, the following are some of the more common complications.
Pleural disease
Lung disease can involve the pleura and cause pleural diseases, including pleurisy, pneumothorax, pleural effusion, pleural hypertrophy and so on.
In particular, infectious lung diseases causing pleurisy are common, with symptoms such as chest pain and dyspnea.
Pyothorax
Infectious diseases of the lungs, especially Staphylococcus aureus infection, can produce purulent exudate that enters the chest cavity and causes pus chest.
Symptoms such as high fever and dyspnea may occur.
Infectious shock
Severe infectious lung disease predisposes to infectious shock, especially in the elderly.
It can be manifested as loss of consciousness, decreased blood pressure, cold extremities, excessive sweating, tachycardia and arrhythmia.
Pulmonary heart disease
Severe lung disease can develop into chronic pulmonary heart disease with increased pulmonary vascular resistance, elevated pulmonary arterial pressure, and increased right ventricular loading over time [8].
Acute massive pulmonary embolism can complicate acute pulmonary heart disease.
Pulmonary heart disease often manifests as progressive worsening of dyspnea, inability to lie down at night, easy fatigue, and decreased labor endurance.
Medical treatment
Department of Medicine
Respiratory Medicine
Cough, sputum, hemoptysis, chest pain, shortness of breath, wheezing, fever and other discomforts, it is recommended to consult the respiratory medicine department.
Thoracic Surgery
If you have open chest trauma, or if you find a large nodule in your lungs during a physical examination, it is recommended that you consult the Department of Thoracic Surgery in a timely manner.
Emergency Medicine
In case of hemoptysis, severe chest pain, dyspnea, asphyxia, bruised lips, fainting, or coma, it is recommended to go to the Emergency Department or call 120 emergency immediately.
Preparation for medical treatment
Preparing for your visit: registration, information preparation, common problems
Tips for seeking medical treatment
Before going to the doctor, if you have a fever, you should try to record the change in body temperature.
Chest X-ray or chest CT is often needed, so avoid wearing clothes made of metal. Those who are pregnant or preparing for pregnancy should inform the doctor in time.
Preparation Checklist
Symptom list
Pay special attention to the time of onset of symptoms, special manifestations, etc.
Did you have fever before the consultation, what was the highest temperature, and did the temperature change regularly?
Is there a cough, how long has it been coughing, is there any sputum? What kind of sputum is there?
Is there hemoptysis, is it bright red or dark red? What is the amount?
Is there any chest pain or tightness?
What makes these symptoms worse or relieves them?
Is there any weakness, night sweats, weight loss, or other physical discomfort?
Medical History Checklist
Is there a history of smoking, how many years have you been smoking, and how much do you smoke per day?
What is your occupation and have you been exposed to large amounts of dust, harmful gases, etc.?
Has there been any exposure to potentially infectious patients such as colds, tuberculosis, etc. prior to the onset of illness?
Are there any chronic diseases such as systemic lupus erythematosus or rheumatoid arthritis?
Has the patient been taking oral glucocorticoids, immunosuppressants, etc. for a long time?
Is there a history of preterm labor and intrauterine hypoxia?
Is there any family history of lung cancer?
Checklist
Test results in the past six months, which can be brought to the doctor’s office
Laboratory tests: blood routine, urine test, coagulation function, blood biochemistry (kidney function, liver function, blood lipid, electrolytes), sputum culture, blood gas analysis, tumor markers, etc.
Imaging examination: chest X-ray, CT, magnetic resonance imaging (MRI examination), etc.
Specialized examination: lung function test, lung biopsy pathology report, etc.
Medication list
Medication used in the last 3 months, if there is a medicine box or package, you can bring it to the doctor
Antibiotics: Amoxicillin, Levofloxacin, Cefuroxime, Isoniazid, Rifampicin, etc.
Fever-reducing medications: ibuprofen, acetaminophen, etc.
Glucocorticoids: prednisone, methylprednisolone, etc.
Others: Ambroxol hydrochloride, pneumoconiosis, dextromethorphan, doxophylline, etc.
Diagnosis
The information needed to diagnose different lung diseases is not the same.
Diagnosis is based on
Medical history
The following is not necessary for the diagnosis of the disease, but the presence of the following history may provide some reference for the diagnosis of the disease.
A long history of smoking.
History of exposure to irritating gases such as coal dust and dust.
Allergies to pollen, insects and mites.
History of contact with respiratory infectious diseases, such as close contact with patients with coronavirus infection and mycoplasma pneumonia.
Autoimmune diseases (e.g. systemic lupus erythematosus, rheumatoid arthritis, etc.).
Family history of lung cancer.
Symptoms
Respiratory symptoms such as cough, sputum, hemoptysis, dyspnea and chest pain.
Systemic symptoms such as fever, night sweats, fatigue, weight loss, etc. may or may not be present.
Signs
Inflammatory lesions in the lungs may have dry and wet rales, bronchial breath sounds, etc. In large inflammatory lesions, the lungs are turbid to percussion, palpable tremor is enhanced and bronchial breath sounds can be heard.
Characteristic Velcro rales may be heard in pulmonary fibrosis.
In pleurisy, pleural friction and rubbing sounds may be present.
In the presence of pneumothorax, pleural effusion and atelectasis, there may be tracheal displacement and loss of breath sounds on the affected side.
Lung diseases may have extrapulmonary manifestations, e.g. bronchopulmonary carcinoma may cause pestle-like fingers (toes).
Laboratory Tests
Blood test
According to the indicators such as white blood cell count and classification, it can be initially judged whether there is an infection and roughly determine the type of infection.
Bacterial pneumonia may show increased white blood cell count, increased neutrophil ratio and count.
Increased eosinophils suggest parasitic infection, fungal infection or allergy.
C-Reactive Protein Level Measurement
C-reactive protein (CRP) reflects inflammation in the body and helps determine the type of infection.
C-reactive protein levels are elevated in bacterial infections and can be mildly elevated in non-bacterial infections, and can fluctuate with illness.
However, myocardial infarction, severe trauma, burns, malignant tumors, and connective tissue diseases can also lead to elevated C-reactive protein levels [9].
Pathogenesis-related examinations
It mainly includes pathogen isolation and culture, pathogen antigen, nucleic acid test and so on.
Pathogen isolation culture is the most reliable examination for definitive diagnosis. However, the culture cycle is long and is mostly used for bacterial infections. On the basis of isolation culture, drug sensitivity test can also be conducted, which helps doctors adjust the drug treatment program.
Antigen and nucleic acid testing of viruses can be used for early diagnosis.
The main method of viral nucleic acid testing is polymerase chain reaction, which has the best specificity and sensitivity. Respiratory specimens need to be obtained from pharyngeal swabs, nasal swabs, nasopharyngeal or tracheal aspirates, sputum, etc. Blood specimens can also be obtained from blood draws, and pleural effusions can be obtained from puncture drainage.
Legionella and Streptococcus pneumoniae may also be tested for antigens.
Antigen skin test
A positive allergen skin test in asthma helps in the determination of allergic constitution and desensitization to the corresponding antigen [10].
A positive skin reaction to a tuberculin (PPD) test only indicates infection, but does not confirm disease.
Arterial blood gas analysis
Lung disease can affect respiratory function, and in severe cases hypoxemia and respiratory failure may occur, the severity of which can be determined by arterial blood gas analysis.
Decreases in partial pressure of oxygen, oxygen saturation, oxygenation index, and PH values out of the normal range may occur.
Imaging
Chest X-ray
Commonly used to detect the location and nature of respiratory system lesions.
Chest CT
It can find some lesions that cannot be found in chest radiographs, and is of great value in clarifying the location and nature of lung lesions as well as the degree of tracheal and bronchial patency.
Contrast-enhanced CT has important diagnostic and differential significance for lymph node enlargement and space-occupying lesions in the lungs.
CT pulmonary angiography (CTPA) is important in confirming the diagnosis of pulmonary embolism.
High-resolution CT of the chest (HRCT) is the main tool for the diagnosis of interstitial lung diseases. Low-dose CT should be used for early screening of lung cancer to reduce radiation.
Positron emission tomography (PET)
It can provide more accurate differential diagnosis of lung cancer, mediastinal lymph node metastasis and distant metastasis, and is also valuable in assessing whether certain diseases are in an active stage.
Bronchial arteriography and embolization
It has better diagnostic and therapeutic value for hemoptysis.
Magnetic Resonance Imaging (MRI)
Important in the diagnosis of mediastinal disease and pulmonary embolism and in the assessment of right heart function.
Radionuclide scanning
Application of radionuclide for lung ventilation/perfusion imaging is of high diagnostic value for pulmonary embolism and vascular lesions.
It is also of high reference value for the diagnosis of lung tumors and their bone metastases.
Chest ultrasonography
It can be used for the diagnosis and localization of pleural effusion by puncture, as well as guided puncture of tight pleural lesions.
Bronchoscopy and Thoracoscopy
Bronchoscopy enables direct visualization of lesions, as well as mucosal brushing and biopsy, which helps to clarify the diagnosis of the disease.
Bronchoscopy can also play a therapeutic role, through which foreign bodies can be removed, bleeding can be stopped, and benign and malignant tumors can be treated with high-frequency electrocautery, lasers, microwaves and drug injections. Tracheal intubation can also be done with the guidance of a fiberoptic scope [11].
Thoracoscopy allows direct visualization of pleural lesions and pleural and lung biopsies for diagnosis of pleural and some lung diseases.
Lung biopsy
It is one of the most important methods to confirm the diagnosis of lung disease.
If the lesion is located in the deep part of the lung or mediastinum, it can be sampled by endoscopic methods such as fibrinoscopy, thoracoscopy or mediastinoscopy.
Intrapulmonary lesions that are not adjacent to cardiovascular vessels can be detected by percutaneous lung biopsy under X-ray or CT guidance.
For lesions close to the pleura, percutaneous lung biopsy can be performed under ultrasound guidance.
If the diagnosis cannot be confirmed by other methods, open lung biopsy or TV-assisted thoracoscopic lung biopsy can be performed.
Differential diagnosis
Upper respiratory tract infection
Similarities: Both may present with cough, sputum, fever and other discomforts.
Differences: Upper respiratory tract infections usually do not involve the lungs and can be differentiated by chest X-ray and CT.
Gastroesophageal reflux disease
Similarities: Cough and chest discomfort may occur.
Difference: GERD is usually treated with a light diet, acid suppression (omeprazole), and gastric stimulation (domperidone).
Treatment
Aim of treatment: To control the progress of the disease, to promote remission, to improve symptoms and to prevent complications by focusing on the different causes of the disease.
Treatment principle: Choose the appropriate medication according to the cause of the disease and supplement it with other treatment modalities according to the symptoms.
Medications
Bronchodilators
Including β2 agonists (such as salbutamol, terbutaline, formoterol), cholinergic receptor antagonists (such as ipratropium bromide, tiotropium bromide, etc.), theophylline analogs (such as aminophylline, doxophylline), or compound drugs.
The main effect is to dilate the bronchial tubes and are used in the treatment of asthma, chronic obstructive pulmonary disease and other airflow limiting diseases.
Cough suppressants
Cough is a defense reflex, but coughing seriously affects the quality of life, according to the condition of the appropriate use of central cough suppressants (such as dextromethorphan) or peripheral cough suppressants (such as nalcodone) treatment.
Expectorants
Including sputum-thinning drugs (e.g. guaifenesin) and mucolytic drugs (e.g. acetylcysteine, carbocysteine, etc.).
Glucocorticoids
Used in the treatment of asthma or chronic obstructive pulmonary disease, mostly in inhaled form, e.g. budesonide for inhalation.
For interstitial pneumonia, pulmonary vasculitis, etc., systemic hormone (e.g., prednisone, methylprednisolone, etc.) therapy is mostly used.
Long-term hormone application requires attention to monitoring hypertension, diabetes monitoring, and administration of bisphosphonates to prevent osteoporosis if oral hormones are taken for more than 3 months.
Antibiotics
Different antibiotics are used according to the pathogen of infection and drug sensitivity, some of which are listed below.
For bacterial infections, amoxicillin, levofloxacin, cefuroxime, etc. can be chosen.
For fungal infections, fluconazole, itraconazole, etc. can be chosen.
For mycoplasma and chlamydia infections, azithromycin, roxithromycin, levofloxacin and other treatments are available.
For tuberculosis, isoniazid, rifampicin, ethambutol and other drugs can be chosen for active anti-tuberculosis mycobacteria treatment.
Anti-allergic drugs
In addition to the glucocorticosteroids mentioned above, there are also leukotriene receptor antagonists (e.g. montelukast sodium, zalustat, etc.) and antihistamines (e.g. loratadine, ketotifen, etc.), which can be used to assist in the treatment of asthma, and they are especially suitable for aspirin asthma and allergic lung diseases.
Chemotherapy and targeted therapy for lung cancer
See Lung Cancer for more information.
Oxygen therapy or respiratory support therapy
For patients with respiratory distress and hypoxia, oxygen therapy should be actively given, mostly using nasal catheter and mask oxygen, and non-invasive or invasive ventilation can also be used when necessary.
Interventional therapy
With the help of bronchoscopy and the corresponding technology, airway foreign body removal or mass excision, stent implantation for bronchial stenosis, and so on.
Lung transplantation
Patients with end-stage lung disease are evaluated for lung transplantation, and those who meet the indications are considered.
Respiratory Rehabilitation
Appropriate rehabilitation therapy according to the condition is helpful to promote the recovery of the condition and improve the quality of life of the patients.
Prognosis
Cure
The causes of lung diseases are complex and varied, with different clinical manifestations and severity of the disease, and their prognosis also varies.
For patients with clear cause, no serious lung function damage and no complications, most of them can be completely cured or the progression of the disease can be effectively controlled after timely and effective treatment.
Patients with lung infection generally have a better prognosis, and some of those who are not actively treated or who are seriously ill may die, or may evolve to have residual pulmonary fibrosis.
Some lung diseases, such as massive pulmonary embolism, severe pneumonia, and severe tuberculosis, progress to respiratory failure and have a relatively poor prognosis.
Prognostic factors
The prognosis of lung disease is affected by a variety of factors, and the following factors may lead to a poor prognosis.
Untimely and irregular treatment.
Heavy smoking over a long period of time.
Poor immunity or long-term use of immunosuppressive drugs.
Poor treatment of underlying diseases in other systems, such as poor long-term control of blood pressure and blood sugar levels.
Combined serious complications such as severe cardiovascular and cerebrovascular diseases.
Prolonged bed rest.
Harmful
Symptoms such as cough and fever caused by lung disease can affect work and life.
In severe cases, the disease can lead to death of the patient.
Infectious lung diseases may cause social surface infections, such as tuberculosis, viral pneumonia, mycoplasma pneumonia, etc. can be spread by droplet transmission.
Daily
Daily management
In order to effectively manage patients with lung disease, it is crucial to maintain a healthy lifestyle, which mainly includes smoking cessation, dietary management, life management and psychological support.
Smoking cessation
Strict smoking cessation and avoiding exposure to second-hand smoke.
Dietary management
Maintain a light diet and avoid spicy and stimulating foods.
Eat a balanced diet, increase the intake of vitamins, eat more fresh vegetables and fruits, and increase the intake of high-quality proteins, such as eggs, lean meat and milk.
Life management
Pay attention to rest and proper exercise.
Pay attention to personal hygiene, increase or decrease clothing in time to prevent colds.
Pay attention to room ventilation, maintain appropriate humidity and temperature, reduce cold air stimulation.
Psychological support
It is recommended that the patient’s family members often encourage and comfort the patient, so that the patient can reduce psychological pressure, stabilize mood, avoid anxiety and depression, treat the disease correctly, establish confidence, and actively cooperate with the treatment.
Disease monitoring
Monitor temperature changes when fever develops.
Observe whether symptoms such as cough, sputum, hemoptysis, shortness of breath and chest pain are aggravated or relieved.
When coughing up sputum, observe the color, smell and amount of sputum.
Monitor weight changes.
Monitor changes in oxygen saturation.
Follow-up
Different lung diseases have different treatment cycles and require regular follow-up as prescribed by the doctor, which may range from one week to six months.
Blood tests, lung function, liver function, kidney function, blood lipids, chest X-ray, chest CT, chest ultrasound and other tests may be needed.
Prevention
There are many different types of lung disease, and preventive measures vary, and cannot eliminate the disease, but can reduce the risk of developing it. Some common preventive measures are described below.
Smoking is an important risk factor for lung cancer, chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF) and other diseases. Quitting smoking is the first step in preventing the development or slowing the progression of many lung diseases.
Preventing colds and flu can reduce the risk of many lung diseases by adding clothes in time and avoiding getting cold in the rain.
Reduce exposure to pollen and grass seeds in the spring and fall, and go outside less when air pollution is high.
Avoid crowded places during infectious disease epidemics, and wear a mask when you must go out for personal protection.
Vaccination against influenza or pneumonia is important for the elderly, patients with underlying diseases or immunocompromised patients to prevent influenza and pneumonia and reduce the risk of acute exacerbation of chronic obstructive pulmonary disease (COPD).