Asthma is a condition that affects the airways-the small tubes that carry air in and out of the lungs. With asthma, the airways become over-sensitive and react to things that would normally not cause a problem, such as cold air or dust. Muscles around the wall of the airway tighten up, making it narrow and difficult for the air to flow in and out. The lining of the airways gets swollen (just like your nose during a cold) and sticky mucus is produced, clogging up the breathing passages. With the airways narrowed like this, you can see why it becomes difficult for air to move in and out and why the chest has to work so much. Tightening of muscle around the airways can happen quickly and is the most common cause of mild asthma. It can be relieved quickly too, with the right inhaler. However, the swelling and mucus happen more slowly and need a different treatment. They take longer to clear up and are a particular problem in serious episodes of asthma.

 What causes Asthma?

No one knows exactly what causes asthma. What we do know is:

• Anyone can develop asthma. It is very common in Ireland, where over 470,000 adults and children have asthma.
• It can start at any time of life, although it most often begins in childhood.
• Sometimes it affects several family members e.g. if you have parents or brothers and sisters with asthma or allergy (e.g. Eczema or hay fever) you are more likely to have it yourself.
• Conditions like hay-fever, eczema, or hives, which are usually the result of allergy, may occur along with Asthma.
• Adult onset asthma may develop after a respiratory tract infection.
• Many aspects of modern lifestlyes such as changes in housing, diet and a more sterile home environment may have contributed to the rise in asthma over the last few decades.

 Asthma Symptoms

The usual symptoms of asthma are:

• Difficulty in breathing/shortness of breath.
• A tight feeling in the chest.
• Wheezing (a whistling noise in the chest).
• Coughing-Hoarse, particularly at night.

You may experience one, several or all of the symptoms above. These symptoms may occur in episodes, perhaps brought on by colds or chest infections, exercise, change of temperature, dust or other irritants in the air, or by an allergy e.g. pollen or animals. Episodes at night are common, often waking the patient. A few people have these complaints all the time. You need to see your doctor, who will check that there is not some other explanation. By examining your chest, doing breathing tests and listening to your description of symptoms, the doctor can usually decide if you have asthma and can prescribe some suitable treatment.

Diagnosing Asthma

Your doctor will record a patient history. He may ask you the following questions;

• How long have you had asthma like symptoms?
• How frequent are the symptoms and how they affect your quality of life?
• Have you had an attack or recurrent attacks of wheezing?
• Do you have a troublesome cough at night?
• Do you wheeze or cough after exercise?
• Does the patient experience wheezing, chest tightness, or cough after exposure to airborne allergens or pollutants?
• Do your colds "go to the chest" or take more than 10 days to clear up?
• Are symptoms improved by appropriate asthma treatment?
• Is there a family history of asthma?

The following tests may be performed by your doctor to confirm the correct diagnosis.

1. Spirometry is a simple breathing test that gives measurements of lung function including a reversibility test that measures lung function before and after a dose of reliever to see if it has improved your lung function. This can be helpful with asthma diagnosis.
2. Peak Expiratory flow rate measurements (PEFR); another simple breathing test which may be measured over a period of time, when one has symptoms or even when symptom free, performed in a GP surgery, hospital and even at home.
3. An exercise test to check if exercise worsens your symptoms.

Incidence of Asthma in Ireland

Asthma prevalence is very high in Ireland - we are number four in the world asthma league after Australia, New Zealand and the United Kingdom. Estimates vary, but as many as 470,000 individuals in Ireland have the condition.
There has been a very considerable increase in asthma prevalence in developed countries over the last two decades. While asthma tends to run in families, the reason for the increase is not genetic. It is more likely environmental - either due to a great change in the external environment over this period (allergic substances, pollution, smoking) or a change in our bodies' response to the external environment.

Prevalence:

• Ireland has the 4th highest prevalence of asthma worldwide
• Approximately 470,000 people affected (1 in 8 of population)
• Prevalence in 13 - 14 year old school children increased by 40% between 1995 to 2003 (15.2% to 21.6%)
• Asthma is the commonest chronic disease in childhood and the most common respiratory condition in Ireland.

Burden of Asthma as a Chronic Disease

• Asthma is consistently in the top 20 diagnoses for admission to hospital
• There are more acute admissions every year for asthma than for myocardial infarction
• 5,347 (average ± 159) admissions per year with principal diagnosis of asthma
• 22,052 (average ± 758) admissions per year with secondary diagnosis of asthma
• On average, there were 23,233 ( ±758) bed days used to treat principal diagnoses of asthma and 103,214 (± 5001) to treat secondary diagnoses of asthma each year between 2000 and 2004
• Average length of stay: age 0 to 19 years 3.3 days/admission; this doubles to 6.6 days in the 55-59 age group and more than trebles for those over 75 years.
• 12% increase in admissions in winter months
• 94% of admissions with principal diagnosis of asthma are through Accident & Emergency (consistent year-on-year). (HIPE data 2000 to 2004)

Findings from the Asthma Insights and Realities in Ireland (AIRI) Study in 2002

• 470,000 people in Ireland have asthma - the fourth highest prevalence worldwide
• 90,000 people do not have their symptoms controlled
• Irish adults with asthma lose on average 12 days from work per annum
• Irish children with asthma lose on average 10 days from school per annum

Hospitalisations

• There are approximately 5,500 asthma-related hospital admissions per year.
• Annual A&E visits are four times this figure.
• About 55% of these admissions and visits are by children less than 14 years of age.
• Asthma Deaths- There is more than 1 death from asthma in Ireland every week. 30% of these are under 40 years of age.

https://www.hse.ie/eng/health/hl/living/asthma/aboutasthma/