Q.9 Describe different types of respiratory disorders in man.

Q.9 Describe different types of respiratory disorders in man. Q.9 Describe different types of respiratory disorders in man.


There are a number of respiratory disorders which affect people. The high percentage of respiratory disorders in Pakistan is due to more concentration of air pollutants both in urban and rural atmosphere.

Some of the important respiratory disorders are:


a) Introduction 

It is the inflammation of the bronchi or bronchioles.

b) Causes

i) It results in excessive secretion of mucous into the tubes, leading to the swelling of tubular walls and narrowing of tubes.

ii) It is caused by viruses, bacteria or exposure to chemical irritants (e.g. tobacco smoke)

c) Types 

There are two major types of bronchitis i.e. acute and chronic.

i) Acute Bronchitis 

It usually lasts about two weeks and patient recovers with no permanent damage to bronchi or bronchioles.

ii) Chronic bronchitis 

In chronic bronchitis, the bronchi develop chronic inflammation. It usually lasts for three months to two years.

d) Symptoms 

Symptoms of bronchitis include: Cough Mild wheezing Fever Chills Shortness of breath (especially when doing hard job)

e) Age limit 

The majority of people diagnosed with chronic bronchitis are 45 years of age or older.

ii. Emphysema Introduction 

It is the destruction of the walls of the alveoli.


It results in larger sacs but with less surface area for gaseous exchange. As lung tissue breaks down, the lungs do not come back to their original shape after exhalation so air cannot be pushed out and is trapped in the lungs.


It includes: 1. Shortness of breath ii. Fatigue iii. Recurrent respiratory infections. iv. Weight loss  By the time the symptoms of emphysema appear, the patient has usually lost 50% to 70% of his/her lung tissue.


The level of oxygen in blood may get so low that it causes serious complications.

iii. Pneumonia Introduction 

It is an infection of lungs.

Double pneumonia 

If this infection affects both lungs, it is called double pneumonia.


The most common cause of pneumonia is a bacterium, Streptococcus pneumonia. Some viral influenza virus) and fungal infections may also lead to pneumonia.


When the causative organisms enter the alveoli, they break the lung tissues and the area is filled with fluid and pus.


It includes a cold that is followed by a high fever, shivering, and a cough with sputum production. Patient may become short of breath.


The patients skin colour may change and become dusky or purplish. It is due to poor oxygenation of blood


i. Vaccines are available to prevent pneumonia caused by S. pneumonia.

ii. Antibiotics are used in the treatment of this disease.

iv. Asthma


It is a form of allergy, in which there is inflammation of the bronchi, more mucous production and narrowing of the airways.


In asthma patients, the bronchi and bronchioles become sensitive to different allergens (allergy causing factors) e.g. dust, smoke, perfumes, pollens etc. When exposed to any of such allergens, the sensitive airways show immediate and excessive response of constriction. In this condition, the patient feels difficulty in breathing.


It varies from person to person. It includes:

i. Shortness of breath (especially with exertion or at night)

ii. Wheezing (whistling sound when breathing out)

iii. Cough

iv. Chest tightness


The medicine in the form of inhalers with ability to dilate the bronchi and bronchioles are used in the treatment of asthma.

(v) Lung Cancer / Explain lung cancer and Passive smoking


It is a disease of uncontrolled cell divisions in the tissues of the lung.


In lung cancer, cells continue to divide without any control and form tumours. The cellular growth may also invade adjacent tissues beyond the lungs.


The most common symptoms are:

i. Shortness of breath

ii. Coughing (including coughing up blood)

iii. Weight loss


(1) Main cause

Smoking is the main cause of lung cancer.

(2) Other Causes are:

(i) Carcinogens (such as those in cigarette smoke)

(ii) lonizing radiation

(iii) Viral infection

Known number of carcinogens 

Cigarette smoke contains over 50 known carcinogens.

Lung cancer in nonsmokers 

The risk of lung cancer is significantly lower in nonsmokersPassive smoking (the inhalation of smoke from anothers smoking) is also a cause of lung cancer. The smoke from the burning end of a cigarette is more dangerous than the smoke from the filter end.


(i) Eliminating tobacco smoking is a primary goal in the prevention of lung cancer.

(ii) The World Health Organization has called for governments to stop tobacco advertising to prevent young people from taking up smoking.

(iii) If a person stops smoking the chance to develop cancer decreases as damage to the lungs is repaired and contaminant particles are gradually removed.


Lung cancer is the most common cause of cancerrelated deaths and is responsible for more than .

1.3 million deaths worldwide annually.