Asthma is a chronic respiratory condition that causes inflammation and narrowing of the airways, leading to symptoms like wheezing, coughing, and breathlessness. It can be triggered by allergens, irritants, stress, or infections. Understanding asthma types, causes, and diagnosis is important for Class 12 Biology and NEET exam preparation.
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Asthma is a chronic disorder of the respiratory system where the airways become swollen, constricted, and filled with mucus, making breathing difficult. All ages are affected, and while it frequently begins in childhood, it can also appear in adults. Symptoms of asthma include coughing, wheezing, chest tightness, and breathlessness, which can worsen into asthma attacks. It makes it very hard for a person to breathe. The stimuli to this infection can be in the form of an exposure to an allergen or irritant. This can also be triggered by viruses, exercise, and emotional stress. Knowing early warning signs, triggers, and treatment options is crucial for effective management.
Asthma is characterized by spastic contraction of the smooth muscle in the bronchioles, which partially obstructs the bronchioles and causes extremely difficult breathing. It occurs in 3 to 5 per cent of all people at some time in life.
The usual cause of asthma is contractile hypersensitivity of the bronchioles in response to foreign substances in the air. In about 70 per cent of patients younger than age 30 years, the asthma is caused by allergic hypersensitivity, especially sensitivity to plant pollens. In older people, the cause is almost always hypersensitivity to nonallergenic types of irritants in the air, such as irritants in smog.
Based on the underlying reason and the severity of the symptoms, there are many forms of asthma. Asthma is defined by medical professionals as:
Intermittent: When there aren't any asthma attacks, this sort of asthma comes in cycles, allowing the patient to feel normal..
Persistent: When a patient has persistent asthma, they frequently experience symptoms. Symptoms might range from minor to severe. The severity of an asthma attack is determined by how frequently a patient exhibits symptoms.
Adult-onset: This kind of asthma is developed in the patient during the onset of adult age i.e., around 18-20 years.
Pediatric: This kind of asthma, often known as childhood asthma, can affect newborns and toddlers and frequently develops before the age of five. Asthma may be outgrown in kids.
Exercise-induced asthma: This kind is also known as exercise-induced bronchospasm because it is brought on by physical activity.
Occupational asthma: People who work near aggravating compounds are more likely to get this type of asthma.
Asthma-COPD overlap syndrome (ACOS): This kind occurs when a patient has both chronic obstructive lung disease (COPD) and asthma. Breathing becomes challenging in both conditions.
Changes that take place right before or right at the start of an asthmatic condition are known as early warning symptoms. These symptoms are the first indications that the asthma is getting worse and may appear before the more typical asthma symptoms. Majority of the time, these symptoms are not severe enough to prevent the person from carrying out regular tasks. However, the patient can avoid an asthma attack or stop it from getting worse by being aware of these signals. Early warning signs of an asthma include:
Frequent cough, especially at night
Breathlessness
Feeling very tired or weak when exercising
Wheezing or coughing after exercise
Feeling tired, easily upset, grouchy, or moody
Symptoms of allergies or a cold (sneezing, runny nose, cough, sore throat, nasal congestion, and headache)
Trouble sleeping
Other illnesses like bronchitis, vocal cord dysfunction, and even heart failure can resemble the symptoms of asthma.
The major causes of asthma are given below:
Allergies: Asthma risk can increase as a result of allergies.
Respiratory infections: Adolescent children's growing lungs can be harmed by several respiratory illnesses, like the respiratory syncytial virus (RSV).
Environmental factors: After being exposed to items that irritate the airways, people can acquire asthma.
Genetics: The likelihood of the patient having the condition increases if their family has a history of asthma or allergy conditions.
An individual who comes into contact with irritants may experience an asthma attack. Medical professionals refer to these chemicals as triggers. It is simpler to prevent asthma episodes when you are aware of what causes asthma. Some general triggers include:
Air pollution: An asthma episode can be triggered by many outdoor factors. Factory emissions, vehicle exhaust, wildfire smoke, and other factors all contribute to air pollution.
Dust mites: These bugs are present in our homes even though we cannot see them. An asthma attack may result from a patient's dust mite allergies.
Exercise: Some people experience attacks when they exercise.
Mould: Mould can grow in damp areas, which can be problematic for those who have asthma.
Pests: In the home, mice, cockroaches, and other pests can trigger asthma episodes.
Pets: Asthma episodes may be triggered by pets. Breathing in pet dander (dry skin flakes) might irritate the airways if a person is allergic to it.
Strong chemicals or smells: These can trigger attacks in some people.
Certain occupational exposures: At work, one may come into contact with a variety of substances, such as cleaning supplies, flour or wood dust, or other chemicals. If the person has asthma, any of these may be triggers.
An asthma attack is a period of time during which the muscles that surround the airways tense up. Doctors refer to this constriction as bronchospasm. The cells lining the airways create more and thicker mucus than usual during an attack, which causes the lining of the airways to swell or become inflamed. Bronchospasm, inflammation, and mucus production all contribute to symptoms like breathing difficulties, sneezing, breathlessness, and difficulty going about everyday tasks normally. Other symptoms of an asthma attack include:
Extreme wheezing during both inhalation and exhalation
Non-stop coughing
Fast breathing
Pressure or pain in chest region
Retractions i.e., tense muscles in the chest and neck
Problem in speaking
Panic attack
Pale, sweaty face
Blue lips or fingernails
Breathing will become more laboured without prompt treatment, such as a bronchodilator or an inhaler for asthma. The patient won't be able to use the peak flow metre at all as the lungs continue to constrict. Lungs will gradually tighten to the point where there is insufficient airflow to cause wheezing. If the patient's asthma is not well treated, they may eventually lose their ability to speak and start to have bluish lips. The colour change (cyanosis) indicates that the oxygen in blood is steadily declining.
Treatment can help control the symptoms so the patient is able to live a normal, active life. There are options to help manage asthma which include:
Bronchodilators/inhalers: The muscles around the airways are relaxed by these drugs. The airways freely move air since the muscles are relaxed. These medications are used for both intermittent and chronic asthma, and they treat the symptoms as they arise.These are of two types:
Short-acting bronchodilators: Acute asthma symptoms are swiftly reduced or eliminated by short-acting bronchodilators. They last between three and six hours.
Long-acting bronchodilators: A 12-hour period is maintained by long-acting bronchodilators. To prevent asthma episodes, people use these inhalers every day.
Anti-inflammatory medicines: These drugs lessen mucus formation and swelling in the airways. They facilitate the passage of air in and out of the lungs. To manage or avoid the symptoms of persistent asthma, they are prescribed for daily use.
Biologic therapies: When severe asthma symptoms don't go away despite using an inhaler correctly, these are utilised.
Surgery: For people with severe asthma, a technique called bronchial thermoplasty might be recommended. During a bronchial thermoplasty, the patient will be sedated. A slender, flexible tube is inserted into the lungs after being passed via the throat. The muscles around the airways are then heated to assist prevent constriction and the onset of asthma symptoms.
Complementary therapies: Many complementary therapies, such as breathing exercises like the Papworth technique and the Buteyko method, traditional Chinese herbal medicine, acupuncture, ionisers, manual therapies like chiropractic, homoeopathy, dietary supplements, etc., have been proposed as potential remedies for asthma.
Q1. Among the given options, which combination correctly identifies the distinctive pulmonary events present in asthma and emphysema, respectively?
Bronchiole inflammation accompanied by a reduction in respiratory surface area
A rise in bronchiole count and an increase in respiratory surface area
An expansion of the respiratory surface area along with bronchiole inflammation
A decrease in the respiratory surface area coinciding with bronchiole inflammation
Correct answer: 1) Bronchiole inflammation accompanied by a reduction in respiratory surface area
Explanation:
Asthma is characterized by wheezing and breathing difficulties resulting from inflammation of the bronchi and bronchioles. On the other hand, emphysema is a chronic condition that leads to abnormal distension of the bronchioles or alveolar sacs in the lungs, resulting in a decreased respiratory surface area for oxygen and carbon dioxide exchange.
Hence, the correct answer is option 1) Bronchiole inflammation is accompanied by a reduction in respiratory surface area.
Q2. Which of the following options correctly represents the lung conditions in asthma and emphysema, respectively?
Increased respiratory surface; Inflammation of bronchioles
Increased number of bronchioles; Increased respiratory surface
Inflammation of bronchioles; Decreased respiratory surface
Decreased respiratory surface; Inflammation of bronchioles
Correct answer: 3) Inflammation of bronchioles; Decreased respiratory surface
Explanation:
Asthma, a condition characterized by the inflammation and constriction of the bronchial tubes, occurs due to heightened sensitivity to allergens or irritants. This leads to bronchoconstriction, where the muscles surrounding the airways tighten, and an increase in mucus production that can obstruct these passages. The obstruction is temporary and can be reversed with treatment. Symptomatically, individuals with asthma typically experience wheezing, shortness of breath, chest discomfort, and coughing.
Conversely, emphysema results from the deterioration of the alveolar walls, thereby decreasing the surface area available for gas exchange. Consequences include compromised lung elasticity, making exhalation challenging, and trapped air within the alveoli, resulting in hyperinflation. Unlike asthma, emphysema's damage is irreparable. The symptoms associated with emphysema are primarily shortness of breath, a persistent cough, and in severe instances, a pronounced "barrel chest" appearance.
Hence, the correct answer is option 3) Inflammation of bronchioles; Decreased respiratory surface.
Q3. Asthma may be attributed to:
bacterial infection of the lungs
allergic reaction of the mast cells in the lungs
inflammation of the trachea
accumulation of fluid in the lungs
Correct answer: 2) allergic reaction of the mast cells in the lungs
Explanation:
Asthma
Asthma is a difficulty in breathing causing wheezing due to inflammation of bronchi and bronchioles.
Asthma is inflammation of bronchi and bronchioles due to a secretion of mast cells causing allergy.
Hence, the correct answer is option 2) allergic reaction of the mast cells in the lungs.
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The main symptoms of asthma include shortness of breath, wheezing (whistling sound during breathing), chest tightness, and persistent cough. The cough may worsen at night or early in the morning. During an asthma attack, patients may also experience rapid breathing, fatigue, anxiety, and difficulty in speaking full sentences. Severe untreated attacks can be life-threatening.
Early warning signs are subtle changes that appear before a full asthma attack. These include frequent coughing (especially at night), slight chest tightness, unusual tiredness, mood changes, and reduced tolerance to exercise. Some may notice mild wheezing or a drop in peak flow readings. Recognizing these early signs helps patients take preventive medication and avoid severe attacks.
Asthma is classified into different types based on triggers and patterns:
Adult-onset – Developed in the patient during the onset of adult age i.e., around 18-20 years.
Asthma-COPD overlap syndrome (ACOS) – Occurs when a patient has both chronic obstructive lung disease (COPD) and asthma.
Allergic (extrinsic) asthma – triggered by allergens like dust, pollen, or pet dander.
Non-allergic (intrinsic) asthma – triggered by stress, infections, or weather changes.
Exercise-induced asthma – occurs during or after physical exertion.
Occupational asthma – caused by exposure to dust, smoke, or chemicals at the workplace.
Nocturnal asthma – symptoms worsen at night due to hormonal and environmental factors.
Asthma treatment involves long-term control and quick-relief strategies. Long-term medications include inhaled corticosteroids, leukotriene modifiers, and long-acting bronchodilators to reduce airway inflammation. For quick relief, short-acting bronchodilators (rescue inhalers) are used during attacks. Lifestyle measures such as avoiding triggers, quitting smoking, exercising with caution, and maintaining a healthy environment are equally important. In severe cases, immunotherapy or biologic drugs may be prescribed.
Frequently Asked Questions (FAQs)
Risk factors of asthma include blood relation with an asthmatic person, active or passive smoking, being overweight, constant exposure to pollutants and harmful chemicals.
Asthma is preliminarily diagnosed through a test called spirometry. The patient is told to inhale deeply into a tube that is attached to a spirometer, and then to forcibly exhale through it to assess how well the lungs are functioning (pulmonary function).
There is no way to prevent asthma but it is possible to avoid severity of the disease by following a proper medication plan, keeping regular checks on vaccinations especially for influenza and pneumonia, monitoring the breathing regularly to detect early warning signs, and identifying and avoiding asthma triggers.
Children below five years of age already have short, constricted bronchial tubes, and illnesses like head colds, chest colds, and other respiratory infections can irritate and constrict these already-sensitive airways.
During sleep, airways shrink which adds a bit more resistance to the air entering and exiting our bodies. This results in coughing and further narrowing of the airways. The sinuses may then begin to drain, causing an asthmatic reaction.
No, there is no cure for asthma, but the symptoms can be controlled for a healthy lifestyle.