The lungs function to take in air and exchange oxygen and carbon dioxide with the blood. Air enters the lungs through the bronchial tubes, which are lined with cilia--tiny hair-like structures that function to capture foreign particles and germs and propel them back toward the nose and mouth therefore protecting the lungs. Because of the volume of air entering the lungs, they are susceptible to airborne diseases, transmitted through tiny droplets released by coughs and sneezes.
Colds
Rhinovirus describes a family of over 100 viruses that cause respiratory infections with cold-like symptoms. Approximately one-third of all cases of the common cold occur due to an infection with a rhinovirus, according to The University of South Carolina School of Medicine. Rhinovirus infection spreads from person to person through aerosols, tiny droplets released through coughing and sneezing, making it an airborne disease.
Common symptoms of a rhinovirus infection include runny nose, stuffy nose and sore throat. Rhinoviruses can also affect the lungs causing cough and difficulty breathing.
Flu
Influenza viruses, including strains of influenza A, B and C, affect the epithelial cells of the respiratory tract. As these cells die the cilia fail to function properly allowing germs to affect the lungs. Viral particles contained in droplets released in coughs and sneezes transmit the virus from person to person.
Influenza viruses usually cause mild illness, including symptoms of fever, cough, sore throat, runny nose, muscle aches, headache and fatigue. In some cases influenza virus can cause inflammation of the airways in the lungs leading to difficulty breathing, shortness of breath and even death. Although vaccines are available to protect against influenza viruses, the Centers for Disease Control and Prevention reports that in 2009 a strain of influenza virus accounted for approximately 12,000 deaths in the United States.
Tuberculosis
Tuberculosis describes an illness caused by the bacterium Mycobacterium tuberculosis. The bacterium commonly affects the lungs but can also damage other organs of the body. As an airborne disease, tuberculosis spreads through droplets produced by coughs or sneezes of those with an active tuberculosis infection.
Not all those infected with Mycobacterium tuberculosis develop the disease as the immune system can inhibit the bacteria from growing causing it to become dormant. Approximately 10 percent of those infected with the bacteria will develop an active infection, according to the National Institute of Allergy and Infectious Diseases. Active infection causes symptoms including weight loss, a fever, night sweats, loss of appetite, a debilitating cough and chest pain.
