Asthma is an inflammation of the respiratory system, which includes the trachea, bronchi and lungs. The symptoms of asthma are highly variable, but it is generally characterized by the obstruction of airflow through the respiratory system. Asthma is extremely common and affects a significant percentage of the world population. There are many possible causes of asthma, but the general treatment for all forms of asthma is inhaling a corticosteroid.
Asthma has a wide range of severity, so its diagnosis must include a clinical classification. Asthma cases have specific severity classifications, including intermittent, mild persistent, moderate persistent and severe persistent. The criteria that physicians use to classify asthma cases include the total frequency of symptoms and the frequency of nighttime symptoms. They also consider the volume of air that the patient expire in one second, known medically as the FEV1. The variability of the FEV1 is another factor in this classification. Physicians also take the frequency of inhalant use into account when classifying asthma.
The frequency of asthma has been increasing since the 1970s, affecting at least seven percent of the world population as of 2010. Developed countries have a much higher prevalence of this condition than the underdeveloped parts of the world. Asthma UK sufferers number about 5.2 million, or about 20 percent of the population. Areas such as Eastern Europe, Ethiopia, India and Indonesia have an asthma priority rate of less than three percent.
The causes of asthma include genetic and environmental factors. The greatest risk factor for asthma is atopic disease, which is a hypersensitivity to various allergens. A history of atopic disease more than triples a person’s risk of developing asthma. Researchers believe the greater exposure to indoor allergens such as dust mites is an important reason for the greater prevalence of asthma in developed countries. Other causes of asthma include obesity and less common conditions such as Churg-Strauss syndrome, uticaria and periocular xanthogranulomas.
The most common symptoms of asthma include the following:
- Chest tightness
- Shortness of breath
Many conditions make these symptoms worse such as cold, exercise and sleeping. Some asthma sufferers experience chronic symptoms, while others experience acute attacks in response to a specific trigger. Gastro-esophageal reflux disease is a condition present in 80 percent of people with asthma. GERD is a condition in which acid from the stomach enters the esophagus. Researchers believe this symptom of asthma is caused by anti-asthma drugs and changes in pressure within the thoracic cavity.
The medical treatments for asthma are generally divided in those that relieve acute attacks and those that relieve chronic symptoms. A short-acting beta2-adrenoceptor agonist like salbutamol is the most common treatment for acute asthma attacks. An anticholinergic drug such as ipratropium bromide is a common alternative in cases where the patient can not tolerate SABAs. The standard treatment for chronic asthma is a glucocorticoid like budesonide. Severe cases of chronic asthma may the patient to take glucocorticoids orally, instead of inhaling them.