Respiratory system diseases are conditions that affect the different parts of the nose, throat, and lungs. There are many different respiratory system diseases affecting people from all over the world each year. Most of these diseases are caused by infection from viruses, bacteria, and fungi. Some infections can be mild, like the common cold, while others can occur long term and become life-threatening, like asthma and chronic obstructive pulmonary disease (COPD). Other causes of respiratory system disease include genetic predisposition, environmental pollution, and lifestyle factors.
The different respiratory system diseases caused by infection from viruses are often mild and mostly need supportive therapy, like rest and drinking plenty of liquid. Often, such infections are contagious, transferred from one person to another through coughing and sneezing. There are other viral respiratory system diseases, however, that can pose a grave threat to the community, like the swine flu caused by H1N1 virus, bird flu caused by the H5N1 virus, and severe acute respiratory syndrome (SARS) caused by the SARS coronavirus.
Bacterial infections of the respiratory tract include tonsillitis, whooping cough, tuberculosis (TB), and pneumonia, among many others. Symptoms like fever, body weakness, headache, pain during swallowing, and shortness of breath are often present. Some infections are easily cured with the use of antibiotics and plenty of rest, while others require long-term therapy, such as in the treatment of TB, which can require taking six to nine months of regular medication. Pneumonia can also be life threatening, if not managed early.
Fungal infections of the lungs include aspergillosis, cryptococcosis, and histoplasmosis. Travel to endemic areas and frequent exposure to bat and bird droppings can often cause infection in susceptible individuals. People who get infected with fungi are often immunocompromised, which means that their immune system is not working well. These include patients with acquired immune deficiency syndrome (AIDS).
Other respiratory system diseases include asthma and chronic obstructive pulmonary disease (COPD). In asthma and COPD, there is often a narrowing of the airways manifested by shortness of breath. Factors leading to asthma include genetic predisposition and inhalation of harmful substances from the environment, with the disorder mostly manifesting during childhood. COPD, on the other hand, is usually caused by lifestyle and environmental factors like smoking, and is often seen in older people. Smoking has been greatly linked not only to asthma and COPD, but also to the development of lung cancer as well.