Asthma is a chronic, or long-term condition that intermittently inflames and narrows the airways in the lungs. The inflammation makes the airways swell which leads to easy fatigability, wheezing, chest tightness and coughing. People who have asthma may experience symptoms that range from mild to severe and that may happen rarely or every day. When symptoms get worse, it is called an asthma attack. Asthma affects people of all ages and often starts during childhood.
What causes asthma?
The exact cause of asthma is unknown, and the causes may vary from person to person. However, asthma is often the result of a strong response of the immune system to an allergen (allergens are substances in the environment to which our body reacts). For example, exposure to an allergen in the environment, such as pollen or house dust mite may make the airways react strongly. Other people exposed to the same allergen may not react at all, or their response may be different. The reason one person reacts to exposure while others do not is not completely understood, though it may be partially explained by genes.
The genes associated with the immune system determine how our body reacts to different environmental substances. These genes can cause a stronger reaction in the airways in some people causing the development of asthma. Some virus infections in infancy or early childhood, when the immune system is developing, can give rise to asthma.
What are the risk factors?
Exposure to cigarette smoke during pregnancy or in a child’s first few years increases the risk of the child developing asthma symptoms early in life. Exposure to different microbes in the environment, especially early in life, can affect the development of the immune system. Exposures that occur in the workplace, such as chemical irritants or industrial dust, may also be associated with an increased risk of developing asthma in susceptible people. This type of asthma is called occupational asthma. Poor air quality due to pollution or allergens may worsen asthma. Allergens in the air include pollen, dust, or other air particles. Having a parent who has asthma, especially if the mother has asthma, increases the risk of a child developing asthma. People who have asthma often have other types of allergies. They may have food allergies or get a runny or stuffy nose from pollen. Asthma is sometimes associated with obesity.
Signs and symptoms of asthma
How often signs and symptoms of asthma occur may depend on how severe, or intense, the asthma is, and whether the patient is exposed to allergens. Some people have symptoms every day, while others have symptoms only a few days of the year. For some people, asthma may cause discomfort but does not interfere with daily activities.
Signs and symptoms of asthma may include chest tightness, coughing (especially at night or early morning), shortness of breath, and wheezing which causes a whistling sound on exhalation. Asthma symptoms may be triggered by exercise, allergies, cold air, or hyperventilation from laughing or crying.
Asthma attacks are episodes that occur when symptoms get much worse. Asthma attacks can happen suddenly and may be life-threatening. People who have severe asthma experience asthma attacks more often.
How asthma is diagnosed?
From the physical examination, we may find features such as wheezing in chest, runny nose, swollen nasal passages or allergic skin conditions such as eczema.
Several tests may be done to help determine if asthma is likely to be the cause of symptoms. These tests include:
- Pulmonary function tests such as spirometry, which involves breathing in and out through a tube connected to a computer. This measures how much and how fast the air moves when the patient breathes in and out with the maximum effort. This test shows how well the lung is functioning.
- Peak expiratory flow (PEF) to measure how fast the patient can blow air out using maximum effort. This test can be done during spirometry or by breathing into a separate device, such as a tube.
- An allergy test can be done to find out what is the common substance to which the person is allergic to.
In most people, treatment can manage asthma symptoms, allow the person to resume normal activities, and prevent asthma attacks. Treatment usually depends on age, asthma severity, and response to a given treatment option.
Inhaler therapy is the mainstay of asthma treatment. An inhaler is a device which allows the medicine such as steroids and bronchodilators, to go into the airways.
Corticosteroids help to reduce the ongoing inflammation in the airways and bronchodilators keep the airways open by preventing narrowing of the airways.
Various other drugs such as leukotriene modifier and biologics (omalizumab, mepolizumab, reslizumab, etc.) are also used in the treatment of asthma.
In case of very severe asthma attack patient will need emergency care such as intravenous steroids, nebulization, supplemental oxygen, and antibiotics. In some cases, the patient may even need the help of mechanical ventilation.
How to prevent worsening of asthma symptoms and attacks
Certain things can set off or worsen asthma symptoms. These are called asthma triggers and include animal fur and house dust mite. If animal fur is the trigger then that animal should be kept out of the house. Other triggers include emotional stress, influenza (flu), air pollution, cold air, tobacco smoke, and some medicines. It is advisable that asthma patients should stay away from these triggers.
Following a healthy lifestyle and keeping one’s weight in check are important as obesity makes asthma management difficult. Quitting smoking and avoiding second-hand smoke are extremely important in controlling asthma
Dr. Mridul Kumar Sarma | Associate Consultant Pulmonology | Narayana Superspeciality Hospital Guwahati