During an asthma attack, the smooth muscles of the bronchi contract, causing them to narrow, and the tissues lining the airways swell due to inflammation and mucus secretion into the airways. The top layer of the airway lining can become damaged and shed cells, further narrowing the diameter of the airway. A narrower airway requires the person to exert more effort to move the same amount of air in and out of the lungs. In asthma, the narrowing is reversible, meaning that with appropriate treatment or on their own, the muscular contractions of the airways stop, and the inflammation resolves so that the airways widen again, and the airflow into and out of the lungs returns to normal.
The airways narrow in response to stimuli that usually do not affect the airways in normal lungs (triggers). Such triggers include:
Exercise, stress, and anxiety
Many inhaled allergens can trigger an asthma attack, including pollens, particles from dust mites, body secretions from cockroaches, particles from feathers, and animal dander. These allergens combine with immunoglobulin E (IgE, a type of antibody) on the surface of mast cells to trigger the release of asthma-causing chemicals from these cells. (This type of asthma is called allergic asthma.) Although food allergies induce asthma only rarely, certain foods (such as shellfish and peanuts) can induce severe attacks in people who are sensitive to these foods.
Infectious triggers are usually viral respiratory infections, such as colds, bronchitis, and sometimes pneumonia.
Irritants that can provoke an asthma attack include smoke from tobacco, marijuana products, or cocaine, fumes (such as from perfumes, cleaning products, air pollution), cold air, and stomach acid in the airways caused by gastroesophageal reflux disease (GERD).
Additionally, people who have asthma can develop bronchoconstriction when exercising. Stress and anxiety can trigger mast cells to release histamine and leukotrienes and stimulate the vagus nerve (which connects to the airway smooth muscle), which then contracts and narrows the bronchi.
Asthma attacks can vary in frequency and severity. Some people are symptom-free most of the time, with only an occasional, brief, mild episode. Other people cough and wheeze most of the time and have more frequent and severe attacks.
An asthma attack may begin suddenly with wheezing, coughing, and shortness of breath. At other times, an asthma attack may come on slowly with gradually worsening symptoms. In either case, people with asthma usually first notice shortness of breath, coughing, or chest tightness. The attack may be over in minutes, or it may last for hours or days. Itching on the chest or neck may be an early symptom, especially in children. A dry cough at night or while exercising may be the only symptom.
During an asthma attack, shortness of breath may become severe, creating a feeling of severe anxiety. The person instinctively sits upright and leans forward, using the neck and chest muscles to help in breathing, but still struggles for air. Sweating is a common reaction to the effort and anxiety. The pulse usually quickens, and the person may feel a pounding in the chest.
In a very severe asthma attack, a person is able to say only a few words without stopping to take a breath. Wheezing may diminish, however, because hardly any air is moving in and out of the lungs. Confusion, lethargy, and a blue skin color are signs that the person’s oxygen supply is severely limited, and emergency treatment is needed. Usually, a person recovers completely with appropriate treatment, even from a severe asthma attack. Rarely, some people develop attacks so quickly that they may lose consciousness before they can give themselves effective therapy. Such people should wear a medical alert bracelet and carry a cellular phone to call for emergency medical assistance. Research suggests a strong link between stress and asthmatic symptoms and experts suggest better treatment, including confident, self management of the condition, could improve the quality of life for asthmatics. The close links between stress and asthma are clear given the potential consequences of untreated attacks.
An asthma attack can be frightening, both to the person experiencing it and to others around. Even when relatively mild, the symptoms provoke anxiety and alarm. A severe asthma attack is a life-threatening emergency that requires immediate, skilled, professional care. If not treated adequately and quickly, a severe asthma attack can cause death.
People who have a mild asthma attack are usually able to treat it without assistance from a health care practitioner. Typically, they use an inhaler to deliver a dose of a short-acting beta-adrenergic drug such as albuterol , move into fresh air (away from cigarette smoke or other irritants), and sit down and rest.
People who have severe symptoms should typically go to an emergency department. For severe attacks, doctors give frequent (or sometimes continuous) treatment using inhaled beta-adrenergic drugs and sometimes anticholinergic drugs. Supplemental oxygen is also given immediately so as to increase the percentage level of oxygen being breathed in to help raise oxygen levels in the blood.
Part two to be continued….