Asthma is a disease related to respiratory system. To understand asthma it is better to understand the respiratory system and its functions firstly.

Respiratory System:

Respiratory system

The respiration is done through the respiratory tract.


It consists of the following parts:

Nose, sinuses, pharynx, larynx, trachea, bronchi, bronchioles, lungs with alveolar ducts, alveolar sacs, and alveoli.

external image 12385760.jpg


The respiratory tract acts as a passage for air to pass from nose to the lung and back. The trachea divides into bronchi and bronchioles. The exchange of gases takes place in alveoli. The airways are made of C shaped cartilages and smooth muscle. There are mucus glands in the airways which secrete mucus. The bronchi and bronchioles have a lot of elastic tissue.


The main function of the respiratory system is exchange of gases. The heart pumps dirty blood to lungs and then clean blood is sent to the heart for sending it to the body. It supplies oxygen to blood and takes carbon dioxide from blood. It is done through breathing. Oxygen is inhaled and Carbon dioxide is exhaled.


Asthma is a Greek word meaning panting. (Source: Wikipedia) It is characterized by inflammatory reaction of the respiratory tract to various stimuli resulting in reversible obstruction.

It occurs in episodes. It can occur at any age but is usually seen in young persons.


  • It is estimated that asthma has 7-10% prevalence worldwide. The prevalence of asthma has increased significantly since the 1970s. As of 2010, 300 million people were affected worldwide. As of 2009, 300 million people worldwide were affected by asthma leading to approximately 250,000 deaths per year. There is a more occurrence in developed and Westernized countries.

Source: Wikipedia


It is thought to be caused by a combination of genetic and environmental factors.

Asthma is divided into two types according to causes.

Intrinsic (Non allergic)

It occurs as a result of reaction to infections, cold air, exercise and emotional upset.
cough_cough.jpg lad.jpgcold.jpg

Extrinsic (Allergic)
It is started by allergens like food, medicines, pollens, fibers and dust etc. These factors determine the severity and its response to medication.

There is a combination of mucosal inflammation, bronchial muscle constriction and excessive secretion of thick mucus causing bronchial obstruction.

Signs and symptons:

Mild attack
  • Increase heart rate
  • Increased respiratory rate
  • Long expiration
  • Mild Wheezing

Severe Attack

  • Use of accessory muscles of respiration (neck muscles)
  • Diminished breath sounds
  • Loud wheezing (whistling sound)
  • Coughing
  • A blue color of the skin and nails may occur from lack of oxygen.



  • Clinical
  • Chest X ray
  • Blood levels of oxygen and Carbon Dioxide
  • Lung function tests


  • The exposure to allergens is to be avoided.

  • The medicines used are divided into fast acting and long acting. Fast acting is used to treat acute attack and long acting are used for chronic cases.

Fast Acting

  • Short acting beta 2 Adrenergic agonists

Inhalers like salbutamol and erbutaline tare mainly used for treatment in acute and chronic asthma.Inhalation is preferred rout ofadministration to avoid effects on other systems like cardiovascular. These alone can terminate 70% of asthmatic attacks.

Side Effects
Tremors are the most common side effects.

  • Anticholinergic drugs (Ipratropium bromide and tiotropium)

These have particular benefit in patients having heart disease.

  • Supplemental Oxygen to be given immediately when patient presents with acute attack.

Long term control

  • Corticosteroids

These are useful in reducing airways inflammation. Inhaled steroids are the cornerstone of chronic asthma therapy in adults and should be used before oral steroids.

Side Effects
The side effects of inhaled corticosteroids include weight gain, hypertension, glaucoma, cataracts, diabetes and muscle weakness.

  • Leukotriene modifiers (Zileuton)

These are used for severe asthma resistant to maximal dose of inhaled steroids and as a last measure before using systemic steroids.


From the above discussion it is evident that asthma is a serious disease but it can be prevented by bringing about some changes in our life style. Especially allergic or extrinsic asthma can be avoided by preventing allergens. Moreover the patient can manage serious attack by use of appropriate medicines. Therefore it is necessary that awareness is created among people about the disease, its causes, preventing measures and treatment to check the serious consequences.