Asthmatic symptoms are usually quite variable, someone with asthma may go for periods of time without symptoms, and then suddenly have severe episodes for days on end. The most common symptom recognized by both physicians and patients is wheezing. Wheezing is a whistling or rumbling sound that comes from the chest expiration. It may be very loud or barely audible.
The wheezing sound occurs when the bronchial tube – through which we breathe – goes into spasms and narrows down, causing air coming out of the lungs to set up vibrations as the air tries to squeeze through narrower airways. This narrowing of the bronchial tubes also prevents air from moving in and out of the lungs easily, which gives the feeling of shortness of breath (called dyspnea by physicians). Mucus, which normally forms in the bronchial tubes, cannot get cleared easily from the spastic and constricted bronchial tubes. The mucus accumulates and sets off a cough reflex as the body attempts to clear the extra mucus out of the airways. Spasms by the bronchial tubes also triggers coughing. Unfortunately, each of these underlying changes eventually contributes to and aggravates other changes and symptoms.
Investigation of Asthma
- The sputum could be thick and viscous and may indicate eosinophils.
- Chest X–ray indicates a hyperventilated chest. It also helps to differentiate from other causes of breathlessness.
- When a patient has a acute attack, examination of arterial blood gases would point out the severity of the disease.
- A Pulmonary Function Testing may indicate an obstructive pattern of airway disease.