Asthma - Symptoms & Causes

What is Asthma?

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.

Mechanism of Asthma

Asthma affect the airways by:

Bronchospasm

• Swelling of the airway walls causes the bronchioles to become narrower, making it harder for air to move in and out.

• Smooth muscle spasm further constricts the airways, leading to breathlessness and wheezing.

Mast Cell Hypersensitivity

• A mast-cell–mediated allergic response triggers the release of inflammatory chemicals that tighten the airways.

• This mechanism is common in younger patients.

Inflammation

• Tightened bronchiole muscles restrict airflow and make breathing difficulty.

• Thick, sticky mucus blocks the airway lumen, further reducing airflow and hindering gas exchange within the lungs.

Symptoms of Asthma

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.

Types of Asthma

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 Asthma

When there aren't any asthma attacks, this sort of asthma comes in cycles, allowing the patient to feel normal..

Persistent Asthma

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 Asthma

This kind of asthma is developed in the patient during the onset of adult age i.e., around 18-20 years.

Pediatric Asthma

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.

Causes 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.

Asthma Triggers

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:

Allergenic Triggers

• 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.

• 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.

Environmental Triggers

• 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.

• Strong chemicals or smells: These can trigger attacks in some people.

Lifestyle & Clinical Triggers

• Exercise: Some people experience attacks when they exercise.

• 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.

Asthma attack (What Happens Inside the Lungs?)

Asthma attack is described below:

During an Asthma Attack

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.

Symptoms During Attack

Other symptoms of an asthma attack include:

• Extreme wheezing during both inhalation and exhalation

• Non-stop coughing

• Rapid breathing

• Pressure or pain in chest region

• Retractions i.e., tense muscles in the chest and neck

• Blue lips or fingernails

Treatment of Asthma

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 and the airways move air freely. 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.

Surgical Option — Bronchial Thermoplasty

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.

Asthma NEET MCQs (With Answers & Explanations)

Important topics for NEET are:

• Types of Asthma

• Diagnosis of Asthma

Practice Questions for NEET

Q1. Among the given options, which combination correctly identifies the distinctive pulmonary events present in asthma and emphysema, respectively?

1. Bronchiole inflammation accompanied by a reduction in respiratory surface area

2. A rise in bronchiole count and an increase in respiratory surface area

3. An expansion of the respiratory surface area along with bronchiole inflammation

4. 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?

1. Increased respiratory surface; Inflammation of bronchioles

2. Increased number of bronchioles; Increased respiratory surface

3. Inflammation of bronchioles; Decreased respiratory surface

4. 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:

1. bacterial infection of the lungs

2. allergic reaction of the mast cells in the lungs

3. inflammation of the trachea

4. 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.

Also Read:

• MCQs on Disorders of the Respiratory System

• Mechanism of Breathing

• Lung Volumes and Lung Capacity