Asthma is a disease of respiratory airways wherein the process of breathing in a patient becomes obstructed. Sure one must therefore understand the basic anatomy and physiology of the lung in order to tackle asthma better.


The lung is structured in such a way that the main airway trachea branches out into smaller respiratory airways called 'bronchi' which further divide into millions of terminal branches called 'bronchioles'. These can be compared to branches of a tree bulging out of a main trunk. The smallest bronchioles open into air sacs called 'alveoli'. In the alveoli exchange of gases takes place across the blood to purify it. The air anyone breathes passes in-and-out of the lung through network of airways. Normal airways are of sufficient size to allow comfortable passage of the air during breathing.


In a patient with asthma the size of airways becomes narrowed thereby making breathing difficult and it results in short supply of oxygen from lungs to blood. Narrowing of bronchial tubes results in a peculiar high-pitched sound while breathing which is known as a wheeze. Muscles of the chest get strained. In an attempt to relieve breathing obstruction patient coughs repeatedly. In the majority of asthmatic patients this narrowing is intermittent. Usually narrowing of airways occurs when a patient comes in contact with substances such as dust and pollen. Such noxious substances are called trigger factors. If you are an asthmatic then your airways are more sensitive or reactive than a normal individual's and so when these airways come in contact with an allergen they get constricted leading to an attack of asthma.


The tendency of airway reactivity is inherited i.e. it is transmitted from forefathers. Airway reactivity usually increases with common cold, viral chest infections and exposure to allergens. Once airway reactivity is increased then even trivial trigger factors which normally do not cause asthma may induce attack of asthma. This means that once you come in contact with old dust it leads to increased reactivity of airways and activities such as laughing, coughing, crying (which normally do not cause asthma) may lead to increased asthma that time. Patient becomes crippled to a situation where trigger occupies pivotal factor controlling his life.

What causes narrowing of airways in asthma?


It is known that air passages of an asthmatic patient get narrowed due to constriction of muscles, collection of thick mucus secretions and swelling. These three constrictive mechanisms are primarily caused by an airway inflammation. This fact was discovered just two decades back. The process of inflammation starts when a body part is hurt, and is seen as swelling. The trigger factors hurt the airways of an asthmatic patient and cause inflammation. It is the root cause for constriction of airways. Inflammation can be seen in airways by observing biopsy samples under a microscope. An airway biopsy done even in an asymptomatic asthmatic patient shows the marked inflammatory structural changes while the airways of non-asthmatics show no inflammation.

How does asthma manifest?

Asthma manifests itself in various degrees of severity in different patients. Few suffer from it once in a while others may have regular attacks of this. Frequently occurring attacks of asthma in particular patient makes the life more difficult. The main symptoms of asthma are cough, shortness of breath, wheezing sound in breathing. These symptoms are aggravated during the night time. After expectoration of mucus thread, the patient gets much more respite from symptomatic asthma. Many patients develop asthmatic symptoms on exercising vigorously. For this simple reason, the children afflicted with asthma have difficulty while they play. But this problem can be overcome by proper exercise training.

How asthma interferes in breathing?

In asthmatic patient airways get narrowed thereby causing obstruction in supply of oxygen and removal of carbon dioxide. Deprivation of oxygen is not compatible with life and therefore lungs work faster and harder to overcome airway barrier. Fast movement of air through narrowed airways creates whistling sound called wheezing. Cough starts in attempt to overcome the obstruction. It causes fatigue and distress to asthmatic patient. As the attack of asthma becomes more severe, carbon dioxide levels in blood builds up because it can no longer be eliminated by lungs. Deficiency of oxygen and increase in carbon dioxide levels interfere with normal body functions and cause headache, difficulty in concentration, leading to coma and in fatal cases even death.

Why a person breathes?

It seems as if the solution to asthma is to stop breathing. But alas, breathing is required for providing oxygen to body. Oxygen is most vital for life. It is consumed continuously for normal functioning in activities of various organs such as heart, lungs, kidneys, liver, brain, limbs and eyes. Carbon dioxide is liberated as a waste product during these organ activities. Blood ensures a constant oxygen supply and removal of carbon dioxide from these organs. Blood with low oxygen and high carbon dioxide contents from organs, goes to lungs to receive fresh oxygen and removal of waste carbon dioxide. Act of breathing delivers oxygen and removes carbon dioxide from the body.

Triggers and treatments

The disease is an allergic reaction most often triggered by pollen, house dust mites, animals, particularly pet cats and dogs and other environmental effects and virus infections. Stress also has a role as an aggravating factor.

There are numerous forms of medication for asthma, which can be divided between the two categories - relievers and preventers. The relievers are designed to remove the wheezing symptoms and open the airways. The preventers are used to avoid the onset of the symptoms. Both forms of medication aim to avoid permanent damage to the lungs.

What Makes Someone Develop Asthma?
Some people are born with a predisposition toward developing asthma. However, what actually triggers the disease can vary from person to person. Common triggers include environmental tobacco smoke, air pollution, pollen, allergens from animals and insects, abrupt weather changes, biological contaminants such as mold, and viral infections.

Some facts about asthma

Symptoms of asthma can be controlled but tendency of asthma recurrence and the disease (airway inflammation) can not be cured but are preventable.

In 50 percent of patients asthma starts during childhood. Asthma subsides in half of the children while reaching 13-14 years of age.

Tendency to get asthma is inherited. In spite of this, asthma occurs only when one is exposed to trigger factors.

Infection is predominant precipitating factor for asthma in children. Many a times it is termed as bronchitis instead of asthma.

Mental tension can aggravate asthma but can not cause asthma.

Asthma may be fatal if not controlled properly.

Asthma does not make you handicap. Many asthmatics have acclaimed goals in their lives.

Asthma is not a communicable disease. It can not be transmitted from one person to other by any type of physical contact.