21 February 2020 What is asthma and what are the most common symptoms? Asthma is a chronic inflammatory disease of the airways . This inflammation causes: narrowing or obstruction of the airways; airway edema; increased mucus production; excessive reactivity of the bronchi to different stimuli. The most common symptoms of asthma are: cough; wheezing; shortness of breath; chest tightness; tiredness and difficulty to complete daily activities. Who can suffer from asthma? Asthma is a very common disease : About one in 10 people in Western countries can develop asthma over their lifetime. Asthma affects about 700 thousand Portuguese (National Asthma Prevalence Survey, 2010). Asthma affects all age groups , from early childhood to the elderly. Asthma symptoms can begin at any age . In most cases, asthma symptoms start from the age of 10. However, many children have symptoms of asthma even before they are 6 years old. Despite the higher likelihood of developing asthma if in the family other members have the disease, this association is not always present. It is also known that children with eczema or food allergies or allergies to environmental allergens , such as pollen, dust mites or animal fans, are more likely to develop asthma in the future. What is the cause of asthma? The causes of asthma are not fully understood. The appearance of asthma is probably due to an association of hereditary and environmental factors , but the way in which they interact is not fully understood. Allergens, such as dust mites in the house, pollens, fungi and animal fans can be agents that trigger asthma attacks. However, some patients with asthma have no evidence of allergy. Several factors can trigger symptoms or crisis in people who tend to have asthma: infections, usually caused by viruses; some environmental allergens, such as dust mites or pollens; exercise, particularly in cold environments; some emotions, such as anxiety, fear, sometimes even laugh; exposure to irritating agents, such as pollution or tobacco smoke; some medications can trigger symptoms. How is asthma diagnosed? The diagnosis of asthma is essentially clinical , supported by the presence of airway obstruction, bronchial hyperreactivity and airway inflammation. The tests that can help with diagnosis are: respiratory function tests, such as spirometry with bronchodilation test; bronchial hyperreactivity tests, which can be performed with chemical or physical stimuli, such as running or in the laboratory; assessment of airway inflammation, using methods such as the exhaled fraction of nitric oxide. As the allergy is related to a higher likelihood of respiratory symptoms being associated with asthma, clinical evaluation and tests for allergy studies , such as skin prick tests and some blood tests, are also commonly performed. How is asthma treated? Asthma can be treated , and most people can achieve control of their disease . When asthma is controlled, symptoms stop interfering in daily life , allowing a productive and physically active life without limitations, without needing to use relief medication. The medication and its administration are adapted according to age and disease control . There are two types of treatment used to control asthma that can also be used in combination: Control medication , to prevent crisis and symptoms. This group includes anti-inflammatory medicines, such as corticosteroids, which are made by inhalation and reduce airway inflammation. There are other control medications, such as antileukotrienes and inhaled anticholinergic bronchodilators. Relief medication , to relieve asthma symptoms quickly and which can also be used in combination with inhaled anti-inflammatory medication with control function. This group includes bronchodilators, administered by inhalation. The authors of this text are the following allergologists from the Hospital da Luz network: Luís Miguel Borrego, Ana Morais Mendes, Ana Reis Ferreira, Andreia Ferrão, Carlos Braga, Cristina Lopes, Diana Pereira da Silva, Filipa Semedo, Isabel Costa Silva, João Gaspar Marques, Pedro Carreiro Martins, Marta Salgado, Nuno Sousa, Rosa Anita Fernandes, Susana Piedade The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
