Asthma overview
Asthma is a common long term inflammatory disease of the airways of the lungs which is associated with reversible airflow obstruction leading to episodes of wheezing, coughing, chest tightness, and shortness of breath. These episodes may occur a few times a day or a few times per week. Depending on the person they may become worse at night or with exercise. Asthma is thought to be caused by a combination of genetic and environmental factors. Environmental factors include exposure to air pollution and allergens. Other potential triggers include medications such as aspirin.
Causes of asthma
Asthma is caused by a combination of complex and incompletely understood environmental and genetic interactions.
- Environmental factor: Many environmental factors have been associated with asthma’s development such as air pollution and other environmental chemicals. Smoking during pregnancy and after delivery is associated with a greater risk of asthma-like symptoms. Low air quality from factors such as traffic pollution or high ozone levels, has been associated with both asthma development and increased asthma severity.
- Genetic factor: Family history is a risk factor for asthma, with many different genes being implicated. Some genetic variants may only cause asthma when they are combined with specific environmental exposures. Risk for asthma, then, is determined by both a person’s genetics and environmental condition.
Signs and symptoms of asthma
Asthma is characterized by recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing. Sputum may be produced from the lung by coughing but is often hard to bring up. Symptoms are usually worse at night and in the early morning or in response to exercise or cold air. Some people with asthma rarely experience symptoms.
Prevention of asthma
A careful planning of living conditions can help in preventing asthma attacks. These include:
- Vaccination: Vaccination for influenza and pneumonia can help to prevent flu and pneumonia from triggering asthma flare-ups.
- Identifying and avoiding asthma triggers: A number of outdoor irritants ranging from pollen and mold to cold air and air pollution can trigger asthma attacks, so avoiding exposures to these conditions can help in preventing it.
- Adequate breathing monitoring: Recognizing and monitoring warning signs of an impending attack, such as slight coughing, wheezing or shortness of breath can help to prevent asthmatic attacks.
- Identify and treat attacks early: Early and quick detection can help to avoid having a severe attack.
- Take medication as prescribed: Even in cases when asthmatic condition is improving, it is advisable to stick the medications as prescribed to avoid reoccurrence of attacks. For people using medications, double-check medications correctly and taking the right dose.
Pathophysiology of asthma
Asthma is a common pulmonary condition defined by chronic inflammation of respiratory tubes, tightening of respiratory smooth muscle, and episodes of bronchoconstriction There are two major categories of asthma: allergic and non-allergic.
- Allergic asthma: Allergic asthma is the most common type of asthma. Allergic asthma symptoms begin when the body reacts to something a person is allergic to, such as pollen, pet fur, feathers, mites or mould. Allergic asthma tends to run in families where there’s a history of asthma or other allergies, such as hayfever. Because allergens are everywhere, it is important that people with allergic asthma understand their allergy and asthma triggers so they can help avoid them and know what to do when symptoms begin. People with allergic asthma’s airways are hypersensitive to the allergens to which they have become sensitive. Once these allergens get into their airways, their immune system overreacts. The muscles around your airways tighten. The airways themselves become inflamed and flooded with thick mucus.
- Non-allergic asthma: Non-allergic asthma is a condition that is not brought on as an allergic reaction, but is triggered by factors such as exercise, stress, anxiety, cold or dry air and hyperventilation. It usually occurs after mid life as a result of frequent respiratory tract infections and is chronic in nature. Non-allergic asthma attacks usually occur at the time of year when cold infections are common. Symptoms include wheezing, difficulty breathing, purulent nasal discharge and reddish discoloration of the mucous membranes. No residual symptoms are seen on resolution of the attack however there may be over-distention of the lungs and emphysema (damage to the air sacs in the lungs).
Management of asthmatic conditions
While there is no cure for asthma, symptoms can typically be improved. A specific, customized plan for proactively monitoring and managing symptoms should be created. This plan should include the reduction of exposure to allergens, testing to assess the severity of symptoms, and the usage of medications. The plan should be written down and advise adjustments to treatment according to changes in symptoms. The most effective management for asthma is identifying triggers, such as cigarette smoke, pets, or aspirin, and eliminating exposure to them.
Management of asthma can also be through modification of lifestyle by avoidance of triggers which is a key component of improving control and preventing attacks. The most common triggers include allergens, smoke (tobacco and other), air pollution, cigarette smoking and second-hand smoke (passive smoke).
Treatments and drugs
Prevention and long-term control are key in stopping asthma attacks before they start. Treatment usually involves learning to recognize the triggers, taking steps to avoid them and tracking breathing to make sure daily asthma medications are keeping symptoms under control.
Treatment for asthma include:
- Medications: The right medications for the treatment of asthma depends on a number of conditions, age, symptoms, asthma triggers and what works best to keep the asthma under control. Preventive, long-term control medications reduce the inflammation in your airways that leads to symptoms. Quick-relief inhalers (bronchodilators) quickly open swollen airways that are limiting breathing.
- Bronchial thermoplasty: This treatment is used for severe asthma that does not improve with inhaled corticosteroids or other long-term asthma medications. Bronchial thermoplasty heats the insides of the airways in the lungs with an electrode, reducing the smooth muscle inside the airways. This limits the ability of the airways to tighten, making breathing easier and possibly reducing asthma attacks.