about the family history of asthma, allergies including
allergic rhinitis, eczema.
have family history of allergies, asthma have greater chances
of having asthma.
recurrent and persistent cough and cold following exposure to
cold air, changing seasons.
by breathing problem and wheezing
history for exposure to gases, fumes, chemicals etc.
Any history of
emergency room visits or hospitalization following breathing
In the children
diagnosis is mainly clinical. Doctor determines when the
parents first noticed child developing breathing problem,
itchy eyes, nasal stiffness, eczema.
Asthma diagnosis is
suspected in all adult and children whose have following sign
which is a high-pitched whistling sounds when breathing
out—especially in children. (Lack of wheezing and a normal
chest examination do not exclude asthma.)
Cough, worse particularly at
breathlessness or difficulty in breathing
respiratory tract infections (LRTI)
Exercise induced cough/wheeze
examination includes listening to breath sounds over the chest
for possible ronchi or wheeze or rales, examination of nasal passage for evidence
of allergic rhinitis like nasal polyps and deviated nasal
Peak flow meter is a small portable hand held instrument used to
measure peak flow rates, or how well the airways are open.
Asthma is suspected when there is more than 20% diurnal
variation on 3 days or more in a week or for 2 weeks in a PEF
For more information click
Peak Flow Meter.
Lung function testing (Spirometry):
If symptoms and the patients history points towards the
diagnosis of asthma, the physician will perform spirometry to
confirm the diagnosis of asthma.
Spirometer is used to access the airflow obstruction. For
asthma diagnosis airflow obstruction should be at least
To establish airflow obstruction physician uses spirometer to
measure (FEV1, FVC, FEV1/FVC) before and after the patient
inhales a short-acting bronchodilator.
For Obstruction to be present:
1. FEV1 should be
less than 80 percent predicted.
2. FEV1/FVC should
be 70 percent or below the lower limit of normal.
increases 12 percent or more and at least 200
ml after using a short-acting inhaled beta2-agonist (e.g., albuterol, terbutaline).
NOTE: Older adults
may need to take oral steroids for 2 to 3 weeks and then take
the spirometry test to measure the degree of reversibility
generally valuable in children over age 4; however, some
children cannot conduct the maneuver adequately until after age
If there are no
signs of airflow obstruction and asthma is still suspected, the
doctor may perform a challenge test by administrating histamine
or methacholine (a substance which causes airways to contract in
asthmatic individual), or may perform exercise challenge test.
These tests are used mainly in clinical laboratories to evaluate
airway hyper responsiveness.
A trial use of
medications are taken and there is improvement in the symptoms,
this further supports the diagnosis of asthma.
Last edited 20-7-2010