Nearly everyone has suffered from cold symptoms at one time or another. In fact, about one billion colds occur each year in the U.S., according to the University of Pennsylvania Health System. The most common symptoms of this respiratory infection are nasal congestion, sneezing, sore throat, cough and headache. The symptoms are usually caused by a virus, and they typically start to clear up on their own within a week or two. Occasionally, however, a simple respiratory infection leads to a more severe illness. Chest tightness and the presence of a fever are signs that a bacterial infection may be present. In addition, chest-related symptoms that you attribute to a common cold may actually be caused by a primary bacterial infection. These symptoms must be evaluated by a physician for proper diagnosis and treatment.
Catching a Respiratory Infection
You catch a respiratory infection by touching your eyes, nose or mouth after touching a germ-infected surface, or by inhaling infected mist after someone sneezes or coughs. Your body's attempts to fight the infection cause the symptoms, usually within two or three days after you're infected. Most of the time, these are viral infections that cause colds. When your primary symptoms are in your head -- sneezing and sore throat, for example -- the infection is informally referred to as a head cold. When your primary symptoms are chest-related, such as a mucus-producing cough and congestion, you have may a chest cold. Most respiratory infections never progress past this stage.
The congestion that accompanies a chest cold is caused by inflammation and an accumulation of mucus. According to Ask Dr. Sears, this mucus serves as a breeding ground for germs. When bacteria in the mucus multiply, an acute bacterial infection can develop. The side effects of these illnesses include fever, cough, wheezing, chest tightness and, in severe cases, shortness of breath and difficulty breathing.
Bronchitis is an inflammation of the airways that run from the trachea and branch into the chest. Infectious bronchitis is usually viral but it can develop into bacterial bronchitis. Bronchitis is more likely to be bacterial if it follows a cold. Symptoms of infectious bronchitis, whether due to bacteria or virus, include a fever of 100 to 102 degrees F that lasts several days, in addition to a cough that brings up mucus. Yellow and green mucus may, but don't necessarily, indicate bacterial infection. Other side effects include shortness of breath and wheezing, especially in the presence of cold air or strong odors. If your physician suspects that your bronchitis may be bacterial, you'll likely need a mucus culture to determine whether bacteria are, in fact, present, and a chest x-ray to rule out pneumonia. Bacterial bronchitis is treated with antibiotics.
Pneumonia is a collection off more than 50 related infections that cause the lungs to become inflamed. Although viral, or walking, pneumonia, is generally mild, severe infection from bacterial pneumonia can be life-threatening because the inflammation can interfere with your lungs' ability to exchange carbon dioxide and oxygen. A buildup of fluid may also result, and it's possible for the infection to spread beyond the lungs. Most pneumonia is caused by bacteria, according to Cedars-Sinai. Pneumonia commonly occurs after a cold, and some of its early symptoms -- cough and fever, for example -- can be mistaken for a cold. Chest pain, chest tightness, alternating chills and sweats and shortness of breath frequently accompany pneumonia as well. A fever of 102 degrees F or higher and a sudden worsening of a cold or flu that had begun to improve suggest that pneumonia may be present. These symptoms must be evaluated immediately by your physician. Blood tests and a mucus culture may be ordered, and you may need to undergo a chest x-ray or CT scan. Bacterial pneumonia is treated with antibiotics. To prevent a bacterial infection, your doctor may prescribe antibiotics for other forms of pneumonia as well.
Asthma is a chronic pulmonary disease that causes inflammation of the lungs' airways and spasms in the muscles that surround the airways. The irritation that causes the inflammation also leads to excessive mucus production. The spasms and mucus cause a condition called bronchoconstriction that can block the airways. The acute symptoms of asthma that signal an asthma attack include coughing, wheezing, chest tightness and shortness of breath. Although many different irritants and allergens can initiate an asthma attack, attacks can also result from bacterial infections. Asthma can be life-threatening, and acute attacks are medical emergencies. Suspected asthma symptoms must be evaluated by a physician.