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Causes of asthma Part 1-By Dr.Karim

Causes of asthma Part 1-By Dr.Karim

It is chronic inflammation of the respiratory airways characterized by:

– Air flow obstruction that is reversible either spontaneously or with treatment.

– Airway hyperresponsivensess to many stimuli.

– Genetic predisposition (it tends to run in families).

It is the most common chronic respiratory disorder among all age groups.

Chronic is a medical term which means that this disease tends to persist more than 3 months. Another example of chronic illnesses are hypertension (persistent high blood pressure above 120/80 ) and diabetes mellitus (persistent high plasma glucose level above 110 mg/dl after fasting for 8 hours).

Inflammation means redness, hotness, swelling, pain and loss of function of the affected organ. It is an immune system response to any harmful stimuli such as injury, infection and irritation. Inflammation is a beneficial response as the inflamed organ gets increased blood supply through the dilatation of its supplying blood vessels. This helps in increasing the rate of organ repair.

Blood carries red blood cells, white blood cells, neutrophils, basophils …..etc. The first blood component to reach the inflamed site is the neutrophils which secrete certain chemicals – called cytokines- that kill the causative organism. These cytokines might also cause some damage to the organ itself.

Remember :Redness and hotness are due to increased blood supply , pain and swelling are due to cytokines.

Exp.Symptoms of asthma.

The red circle just adjacent to the wound is an inflammatory response.









The cause of chronic inflammation in asthmatics is that they have hypersensitive (hyperresponsive) airways. This means that their airways respond to normally harmless stimuli with an inflammatory response, thus their airways are persistently inflamed.

The causatives of asthma can be divided into 2 categories :

A. Extrensic (Allergic) :

These always appear during early childhood.

Examples :

Dust: Although dust itself isn’t an allergen , there are allergic components in it as dust mites. These are small insects found in dust in the wardrobes, carpets, curtains, soft toys. Asthmatics should properly ventilate their homes. They are the most common type of allergens.

Triggers of asthma.

Dust Mites (Microscopic view)








Pollen: which comes from plants in their mating season in Spring. Asthmatics should wear protective masks during spring.

Pets: such as cats and dogs. Dander from these animals cause bronchial asthma. This type of allergen is prevalent in many countries as many keep pets in their homes. Good news for cat lovers is that a number of epidemiological studies suggest that close contact with a cat or dog in very early infancy reduces subsequent prevalence of asthma later in life.

Cockroaches: prevalent in tropical environments.

Tobacco smoking: and passive smoking. It is an important risk factor in the development of childhood asthma. The earlier and the greater the degree of exposure to tobacco smoke, the greater the likelihood of developing childhood asthma. Smoking during pregnancy also causes an increased risk of the infant to develop bronchial asthma later in life. This is due to the growth retardation of the lungs caused by persistent exposure of the infant’s lungs to nicotine.

Air pollution: Asthmatics shouldn’t live close to factories and streets crowded with vehicles.

Remember: These allergens are normally harmless stimuli to normal individuals. They only cause bronchial asthma in patients with hyperresponsive airways(asthmatics).

B. Intrinsic (non allergic) :

This tends to occur later in life . It is usually secondary to recurrent chest infections and it tends to be triggered by exposure to cold air, dry air, laughing, coughing and psychological factors as anxiety, fear.

In infants, the principle cause of bronchial asthma is viral respiratory infections rather than allergens.

Examples :

Respiratory syncytial virus (RSV), Parainfluenza and Rhino virus ,during the 1st 2 yrs of life.

Influenza virus which is much more common in older children and adults.

Non-steroidal anti inflammatory drugs (NSAIDs) as aspirin, ibuprofen, piroxcam, diclofenac sodium.

  1. issraa

    what about treatment ?

    • Dr. Karim
      Dr. Karim04-21-2012

      Thanks for your reply, treatment will be discussed in the following articles.

  2. Muhammad Islam
    Muhammad Islam04-20-2012

    Hi Dr. Karim Ahmad:
    what is the suitable treatment of Asthma for a hypertensive patient?
    and for a diabetic patient too?


    • Dr. Karim
      Dr. Karim04-21-2012

      Hi Muhammad,
      Thanks for your question. Treatment of asthma will be discussed in another article , please check again soon

  3. Ahmad

    Great article, thanks for the great info

    • Dr. Karim
      Dr. Karim04-21-2012

      Thanks for your reply, you are welcome

  4. Marwan

    I realy liked the article, it was very informative. Waiting for your next one

  5. mona

    Thanks alot for the great article. Looking forward for your next one

  6. Dr-amr gomaa
    Dr-amr gomaa04-20-2012

    very nice dr karim

    • Dr. Karim
      Dr. Karim04-21-2012

      Thank you Dr-Amr

  7. Peter Marzouk
    Peter Marzouk04-21-2012

    great article Karim ,, waiting for the plan of treatment ..

    • Dr. Karim
      Dr. Karim04-21-2012

      Thanks Peter, the next article will be on Pathophysiology of bronchial asthma , please check again soon.

  8. Bassem Mostafa
    Bassem Mostafa04-21-2012

    that was an interesting article, keep up the good work karim and waiting for more 🙂

  9. example


  10. Umar Khan
    Umar Khan10-21-2013

    I am the old patient of Asthma….Allergy and have treated from various medical specialists in Pakistan, but no avail upto date. pl tell tell me the suitable medicines which is available in the local market in Pakistan.

  11. Umar Khan
    Umar Khan01-15-2014

    Presently I am in very trouble particularly during night close of my nose and headache and disturb sleeping.
    Sir it is requested that I may please be suggested/prescribed suitable medicines which is necessary for the said problem. I am old patient of Allergy and Asthma and continue the medicines like.
    Ceretide Inhaler.
    Rinoclenil Nasal Spray
    Rhinosone N.Spray
    Ezythromycine Cap 500mg
    Rigix Tab

    Sir it is once again requested that I may please be prescribed essential treatment. I shall wait for your E.mail and advice please.

    Umar Khan Bajauri

    • Webmaster

      Hello Umar Khan again,

      Thanks for your query again.

      For individuals like you with allergic asthma, identifying and treating your allergies is instrumental in treating your asthma. An allergist can help you determine your allergies and prescribe an effective treatment plan.

      Dr.Kamz MD

  12. Umar Khan
    Umar Khan01-16-2014

    Dr. Karim Sahib,
    I requested your good self that please prescribe some suitable medicines which are required for Allergy/Asthma, u have not prescribed any thing in ur E.mail response.
    I shall wait for your good advice.
    I hope you will accept my request and oblige.

    • Webmaster

      Hello Umar Khan again,


      If you read this comment (Umar Khan’s) – hope you will answer favorably.


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