Asthma (from the Greek ἅσθμα, ásthma, “panting”) is a common chronic inflammatory disease of the airways characterised by variable and recurring symptoms, reversible airflow obstruction and bronchospasm. Common symptoms include wheezing, coughing, chest tightness, and shortness of breath. Asthma is thought to be caused by a combination of genetic and environmental factors. Its diagnosis is usually based on the pattern of symptoms, response to therapy over time and spirometry. It is clinically classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. Asthma may also be classified as atopic (extrinsic) or non-atopic (intrinsic) where atopy refers to a predisposition toward developing type 1 hypersensitivity reactions.
In very severe cases, intravenous corticosteroids, magnesium sulfate, and hospitalisation may be required. The prevalence of asthma has increased significantly since the 1970s. In 2011, 235–300 million people globally were diagnosed with asthma, and it caused 250,000 deaths.
Severe & Brittle Asthma
Severe & Brittle asthma can also be known as difficult asthma. Up to half a million people, are living with severe asthma symptoms despite taking high doses of medicine correctly and avoiding triggers. It can be unstable, unpredictable, with frequent severe attacks and hospital admissions. Often no consistent trigger factors can be identified.
There are two recognised types of brittle asthma:
- Type 1 is marked by consistent wide variation in peak flow readings and symptoms despite regular medication at high doses and frequent admissions to hospital. More commonly seen in women and affects people aged 15 to 55. Possible trigger factors include allergens (e.g. house dust mite, pollen, cat and dog dander), life trauma or ongoing stressful situations, and symptoms related to the menstrual cycle.
- Type 2 attacks come on very quickly without warning and often require emergency hospital admission and may lead to unconsciousness. Between attacks people can feel well controlled. It is equally common in both men and women. Possible trigger factors include inhalation of something that causes an allergic reaction.
Those with Type 2 brittle asthma should be provided with a MedicAlert bracelet, so that attending people can be alerted when they have an attack. People with difficult asthma may often feel frightened and isolated.
Severe asthma is difficult to define. It is made more confusing because there are other words people use to describe it (difficult, brittle, refractory) and people use the term severe asthma in different ways.
A chronic condition is a human health condition or disease that is persistent or otherwise long-lasting. Chronic asthmatic bronchitis refers to an underlying asthmatic problem in patients in whom the asthma has become so persistent that clinically significant chronic airflow obstruction is present despite anti-asthmatic therapy. The symptoms of chronic bronchitis are generally also present.
Chronic obstructive pulmonary disease (COPD) is the name for a collection of lung diseases including chronic bronchitis, emphysema and chronic obstructive airways disease. People with COPD have difficulties breathing, primarily due to the narrowing of their airways, this is called airflow obstruction.
Typical symptoms of COPD include:
- increasing breathlessness when active
- a persistent cough with phlegm
- frequent chest infection.
- The NHS says around 900,000 people in the UK have been diagnosed with COPD and about two million people have the condition but have not been diagnosed. COPD causes 25,000 deaths a year.
Emphysema is a long-term, progressive disease of the lungs that primarily causes shortness of breath. In people with emphysema the lung tissues necessary to support the physical shape and function of the lung are damaged. It is included in a group of diseases called chronic obstructive pulmonary disease or COPD (pulmonary refers to the lungs). Emphysema is called an obstructive lung disease because the destruction of lung tissue around smaller airways, called bronchioles, makes these airways unable to hold their shape properly when you exhale. This makes them inefficient at transferring oxygen into the blood, and in taking carbon dioxide out of the blood.
Bronchitis is an inflammation of the mucous membranes of the bronchi (the larger and medium-sized airways that carry airflow from the trachea into the more distal parts of the lung parenchyma). Bronchitis can be divided into two categories: acute and chronic.
Acute bronchitis is characterised by the development of a cough or small sensation in the back of the throat, with or without the production of sputum (mucus that is expectorated, or “coughed up”, from the respiratory tract). Acute bronchitis often occurs during the course of an acute viral illness such as the common cold or influenza. Viruses cause about 90% of acute bronchitis cases, whereas bacteria account for about 10%.
Chronic bronchitis, a type of chronic obstructive pulmonary disease (COPD), is characterised by the presence of a productive cough that lasts for three months or more per year for at least two years. Chronic bronchitis usually develops due to recurrent injury to the airways caused by inhaled irritants. Cigarette smoking is the most common cause, followed by exposure to air pollutants such as sulfur dioxide or nitrogen dioxide, and occupational exposure to respiratory irritants. Individuals exposed to cigarette smoke, chemical lung irritants, or who are immunocompromised have an increased risk of developing bronchitis.