Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, the muscles of the bronchial tree become tight and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound. Mucus production is increased.
Most people with asthma have periodic wheezing attacks separated by symptom-free periods. Some asthmatics have chronic shortness of breath with episodes of increased shortness of breath. Other asthmatics may have cough as their predominant symptom. Asthma attacks can last minutes to days, and can become dangerous if the airflow becomes severely restricted.
Acute bronchitis is generally caused by viral respiratory infections and typically appears just as the symptoms of the initial infection are waning. These viral infections may be caused by any number of respiratory viruses including the rhinoviruses which cause the common cold. These viruses produce bronchial inflammation which sets the stage for bronchitis and, in some cases, a secondary bacterial infection. Early symptoms may include a tickle deep in the throat just above the sternal notch which progresses into an irritating dry cough.
Bronchitis is an inflammation of the main air passages to the lungs. Bronchitis may be sudden (acute) and short-lived, or chronic, meaning that it lasts a long time and often recurs. To be classified as chronic, you must have a cough with mucus most days of the month for three months out of the year. Chronic bronchitis is a long-term condition of excessive mucus with a productive cough . This ongoing condition is inflammation but not infection. It blocks air flow in and out of the lungs.
Chronic bronchitis, like emphysema, is also known as chronic obstructive pulmonary disease . As these lung conditions progress over time, you become increasingly short of breath, have difficulty walking or exerting yourself physically, and may need oxygen on a regular basis.
Cigarette smoke is the chief cause of chronic bronchitis, including long-term exposure to second-hand smoke.
Chronic obstructive pulmonary disease (COPD) refers to chronic lung disorders that result in blocked air flow in the lungs. The two main COPD disorders are emphysema and chronic bronchitis, the most common causes of respiratory failure. Emphysema occurs when the walls between the lung's air sacs become weakened and collapse. Damage from COPD is usually permanent and irreversible.