Asthma is a common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Common symptoms include wheezing, coughing, chest tightness, and shortness of breath. Asthma is thought to be caused by a combination of genetic and environmental factors. Its diagnosis is usually based on the pattern of symptoms, response to therapy over time. In severe cases hospitalization can be required.
Chronic obstructive pulmonary disease (COPD), also known as chronic obstructive lung disease (COLD), this disease defined by persistently poor airflow in the lungs as a result of breakdown of lung tissue (known as emphysema) and dysfunction of the small airways. Primary symptoms include: shortness of breath, cough, and sputum production. Common symptoms of COPD are shortness of breath. People with COPD commonly describe this as: "My breathing requires effort," "I feel out of breath," or "I can't get enough air in". People typically first notice shortness of breath during vigorous exercise when the demands on the lungs are greatest. Over the years, dyspnea tends to get gradually worse so that it can occur during milder, everyday activities such as housework
Influenza, commonly known as "the flu", is an infectious disease of birds and mammals caused by RNA viruses. Flu can occasionally lead to pneumonia, either direct viral pneumonia or secondary bacterial pneumonia, even for persons who are usually very healthy.[4][5][6] In particular it is a warning sign if a child (or presumably an adult) seems to be getting better and then relapses with a high fever as this relapse may be bacterial pneumonia.[7] Another warning sign is if the person starts to have trouble breathing.[6] influenza is transmitted through the air by coughs or sneezes, creating aerosols containing the virus. Influenza can also be transmitted by direct contact with bird droppings or nasal