Asthma is a chronic inflammatory disease of the airways. This is, of course, a very general definition which you will find everywhere, but it doesn’t really tell much. Asthma is a very complex medical disorder which can be of varied origin, severity, and age of onset. It is also very common, with an incidence of 0.38 percent among adults and 1.25 percent among children. People who live with asthma should follow their doctor’s instructions on how to manage their condition properly, but first, they should be aware of some important facts. Here are six things you should know if you are suffering from asthma.
What Happens To The Airways and Lungs In Asthma?
The airways begin with the larynx and trachea and narrow down to the small bronchioles on their way through the lungs. In asthma, substances called interleukins, are produced excessively. Along with histamine, interleukins contribute to airway obstruction in three main ways:
- By stimulating the mucosa of the bronchial walls to produce more mucus, which is viscous and sticky
- By inducing contractions of the small muscle bands that surround the airways
- By producing inflammation and consequential swelling of the mucosa
All these processes obstruct the airways and therefore prevent normal air flow, especially during exhalation.
What Causes Asthma?
The mechanism of development of asthma is well researched, but we still don’t know what initiates it. There are certain risk factors, but some people develop asthma even without exposure to them. The most common opinion among researchers is that asthma appears due to a combination of genetic and environmental risk factors. Some of the most frequent factors include:
- Atopic constitution – innate affinity towards the development of allergies
- Young age – Asthma is much more prevalent in children than in adults.
- Frequent respiratory infections – which can alter the local immune response of the airway mucosa
- Black race – Asthma is more frequent and usually more severe in black race than in other races.
- Air pollution – Quite a few studies have suggested that increased concentration of some air pollutants can contribute to the development of childhood asthma.
- Working environment – There are workplaces with increased concentration of harmful substances, which can cause so-called occupational asthma.
Asthma: Signs And Symptoms
Signs and symptoms of asthma can vary significantly, depending on the age of onset, the severity of allergies, exposure to environmental agents, and other unknown factors. Symptoms and signs in asthma patients appear in phases or attacks when a provoking agent is present, or sometimes for no obvious reason.
COPD can have similar symptoms, but unlike asthma, they do not fully subside between attacks. COPD patients always have some level of airway obstruction, while airway obstruction in asthma is considered fully reversible.
The most common symptoms of asthma include:
- Shortness of breath – This is a common symptom in almost all disorders related to the lungs and airways. We all know that there are two repetitive activities during breathing – inhalation and exhalation. Patients with obstructive lung disorders, including asthma, will typically report that they have a hard time exhaling, while inhalation is easier for them. This occurs because inhalation is by nature an active process which requires contraction of the main respiratory muscle – diaphragm. Normally, exhalation should be a passive process, but in patients with asthma, airways are obstructed and auxiliary respiratory muscles are needed in order to help the patient to exhale. These are intercostal muscles (muscles between the ribs), and abdominal muscles. Contraction of these muscles pushes the air out of the lungs, but that requires effort. This is why exhalation is often prolonged and strenuous activity for persons with asthma.
- Coughing – Coughing is a very frequent symptom in persons with asthma. A cough is usually nonproductive (dry), and it can occur during physical activity or at night. There is a recognized type of asthma which has a cough as the only symptom. It is not very common, but long dry cough should absolutely undergo a detailed investigation of respiratory function.
- Weakness and fatigue – Due to impaired airflow through the airways, oxygen concentrations in persons with asthma can be lower than normal. This causes fatigue during physical activity. Also, additional efforts to breath out can contribute to loss of energy while exercising.
When it comes to signs of asthma, you or your doctor can notice them, and they include:
- Wheezing – wheezing sounds are common during expiration, especially in mild to moderate asthma. When an asthma attack becomes severe, these sounds are absent, as there is not enough air flow to produce wheezes.
- Expiratory crackles – This is one of the signs that can only be detected by your doctor during lung auscultation with a stethoscope.
Asthma is one of the diseases that require additional tests when making an accurate diagnosis. These tests include:
- Bronchodilator test
- Asthma provocation tests.
After a physical examination, your doctor may order these tests in order to confirm the diagnosis. These tests measure the lung capacities and lung volumes. The most affected parameter is FEV1, which is forced expiratory volume in the first second of expiration. Basically, you exhale through the special tube as hard as you can after maximum inspiration, and if the FEV1 is lower than 80% of predicted for your age, gender, bodyweight, and height, then you have some sort of airway obstruction.
If spirometry shows that FEV1 is <80%, the next test doctors will usually perform is the bronchodilator test. This includes inhalation of a bronchodilator drug (usually albuterol) three times in intervals of 30 seconds. After that, if lung function improves by more than 12 percent, doctors conclude that the patient suffers from a reversible airway obstruction, which is typical for asthma.
Asthma in children usually disappears by adolescence, but there are a number of cases in which symptoms persist after childhood. Nevertheless, in patients with asthma, treatment should be directed towards two goals:
- Symptom relief (short term) and
- Reducing chronic inflammation of the airways (long term).
Symptoms in acute asthma attacks must be treated with bronchodilators, such as albuterol and ipratropium bromide. In severe cases, or if there is no response to standard bronchodilators, doctors are forced to use aminophylline.
Long-term treatment for asthma patients includes usage of inhalation corticosteroids, as well as a combination of long-term bronchodilators and corticosteroids. This continuous treatment can reduce the frequency of asthma attacks and is absolutely necessary in all patients with diagnosed asthma.
Avoiding known triggers of asthma attacks, sticking to prescribed therapy, and regular controls of lung function can enable most persons with asthma to have a normal life with rare or no episodes of acute asthma attacks. Untreated asthma can progress to more severe pulmonary disorders, such as emphysema and COPD, which are characterized by irreversible changes to the lungs and airways.