Asthma - Symptoms, Types, Treatment

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 (How It Affects Airways)

Asthma affect the airways by:

Bronchiole Inflammation

• 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.

Hypersensitivity Reaction

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

• This mechanism is common in younger patients.

Airflow Obstruction

• 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

A person who is suffering with asthma may possess some common problems:

• Tightness in the chest

• Wheezing

• Breathlessness

• Coughing

• Increased mucus production

• Asthma attacks, ranging from mild to life threatening.

• Oxygen cannot enter the bloodstream and hence cannot enter vital organs such as the heart. In such high symptom cases people need urgent medical attention.

Types of Asthma

Different types of asthma are:

Childhood asthma

When a baby is born before the gestation period of the pregnancy it can lead to childhood asthma. When a child is premature the lungs of the child are not fully developed and then the baby has to put on the ventilator for the major functioning of the lungs. Stimuli of childhood asthma :

• When a baby catches a cold, it can lead to asthma.

• If a baby has asthma then the allergy caused by the pollen grains can be very harmful.

• There may be allergy to chemicals if a child has asthma.

• Childhood asthma can be triggered by coming in contact with perfume or spray.

Adult Onset Asthma

If someone has not been exposed to asthma in childhood then it is not necessary that he or she will never have asthma. Asthma can develop later in life when a person attains adult age. When asthma occurs during the adult days then it is more dangerous and leads to the more severe symptoms.

This type of asthma can sometimes lead to the death of the person. This asthma is triggered by some of the allergens such as chemicals, perfume and also the pollen grains.

Allergic Asthma

It is a connecting link between allergies and asthma but till now nobody knows the connection between both of them. Not all allergies can lead to asthma. Allergies such as allergy from the pollen grains and some of the chemicals can sometimes lead to asthma but sometimes these cannot lead to asthma and they are only the form of allergies.

Occupational Asthma

This is the most dangerous type of asthma in which the asthma occurred due to your occupation. When working in industries such as in the bangle and mining industry, the dust enters into bronchioles and leads to bronchitis. It also leads to the inflammation of the lungs. This type of asthma can be more easily seen in the people with low employment and the poor areas.

Causes and Triggers of Asthma

Asthma is mainly caused by inflammation and narrowing of the airways due to genetic and environmental factors. Some major causes include:

• Sensitive immune system: hyper reactive airways responding strongly to stimuli.

• Environmental exposure: air pollution, cigarette smoke, dust, or occupational irritants.

• Allergies: allergic rhinitis, hay fever, or other atopic conditions increase risk.

• Genetic: family history of asthma, allergies, or eczema.

• Exercise: especially vigorous activity without proper warm-up (exercise-induced asthma).

Diagnosis of Asthma

There are many test for determination the asthma :

Spirometry

It is a lung test that measures the lung volumes and lung capacity. It finds out the obstruction that comes in the pathway of the airway. It is done by a simple instrument that is termed as the spirometer.

Nitric Oxide Test

In this case the air is artificially inhaled by a machine called a handheld device. The air is allowed to be exhaled and if the exhaled air contains the nitrogen dioxide then it can be a confirmatory test. Nitrogen dioxide is usually formed due to the presence of inflammation in the lungs.

Challenge Test

This kind of test is usually done when the diagnosis is not possible by any other test. This test makes the use of two different agents that are known as mannitol and methacholine. When these two agents inhale the air we get narrow only when the asthma is present and if asthma is not present the airway will not get narrower.

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

• Larynx