Asthma is a chronic problem of the airways. It is often thought to be a disease that starts in childhood and is restricted to younger people. However, asthma can start at any age and persist throughout life although it more often arises in young children. It is important to differentiate asthma from another type of lung disease known as COPD (chronic obstructive pulmonary disease). Types of COPD – emphysema and chronic bronchitis – may only be seen in the late years of life despite having started much earlier. Emphysema and chronic bronchitis are not the same diseases as asthma.
Asthma is a condition where the airways become inflamed and narrowed by overreacting to certain substances and irritants. This is a highly simplistic yet accurate description of the condition but asthma is actually a complex disease. Normally the immune cells containing chemicals that trigger inflammation are somewhat dormant in the walls of the airways. If any irritant enters the airways or even an invading microbe, then these cells and chemicals spring into action. It neutralizes the threat and gradually inflammation eases. This is the body’s protective mechanism.
However, the process is a bit more complicated in asthmatics. The immune cells and inflammatory chemicals are easily stimulated and released even when there is no threat to the airways. The inflammation also is more severe than is necessary and persists for a longer period of time. All of this affects breathing because the airways are narrowed, swollen and filled with mucus. It is known that asthma is often associated with allergies and exposure to pollen, dust and animal hair among other allergens. However, some types of asthma are triggered and persists despite no significant contact with allergens.
Our airways need to be opened to a sufficient degree to allow air to travel in and out freely. With asthma, the tiny muscles in the walls of the lower airways (bronchi) begins to contract thereby narrowing the airways. Furthermore the inflammation causes the walls to swell and release copious amounts of mucus which also narrows the interior of the airway (lumen). Ultimately air flow is significantly impeded and a person has difficulty breathing.
The term wheezing is often thought to be synonymous with asthma. It is not. Wheezing is an abnormal breathing sound heard when air is moving through a narrowed airway. It is a symptom while asthma is a disease. Wheezing can occur with other lung and airway diseases like chronic bronchitis and even emphysema. A tight chest, difficulty inhaling and exhaling as well as gasping for air are other symptoms that may also be seen with asthma.
All these symptoms are features of asthma and may be present to different degrees in individual asthmatics or with each asthmatic attack.