The U.S. Centers for Disease Control and Prevention (CDC) reports 1.2 million hospitalizations and more than 55,000 deaths occurred in 2006 due to pneumonia. Pneumonia is a specific type of lung infection. The lungs are made of the airways, which clean, warm and transport air; the air sacs, which exchange oxygen and carbon dioxide with the blood; and the interstitium, a matrix of cells, blood vessels, lymph channels, collagen and elastic fibers that nourish and protect the lungs and give them structure. Pneumonia is an infection of the air sacs or lung interstitium. Early pneumonia symptoms vary depending on age and the causative agent.
Fever
Fever is a common early symptom of pneumonia. It may be persistent or come and go. Those with fever may also experience chills, sweating and rigors (shaking chills). Importantly, infants, older adults and people with a weakened immune system may not have fever with pneumonia.
Increased Respiratory Rate
People with pneumonia may breathe at an abnormally fast rate. This symptom is called tachypnea. It is usually most noticeable to the sufferer during strenuous physical activity or while lying down--a time when such things tend to come into conscious awareness.
Shortness of Breath
With pneumonia, the body's immune response to the invading germs causes fluid leakage into the air sacs. The air sacs in the affected area temporarily lose their ability to exchange gases with the blood, and shortness of breath may occur. It is usually mild and generally occurs only with physical exertion.
Sore Throat and Hoarseness
Sore throat and hoarseness are early signs of pneumonia caused by viruses, Chlamydia pneumoniae, Chlamydia trachomatis or Mycoplasma pneumoniae. Sore throat and hoarseness do not typically occur with pneumonia caused by other bacteria or fungi.
Weight Loss
Weight loss may be an early symptom of aspiration pneumonia--accidental inhalation of food or secretions from the mouth or esophagus into the airways. This symptom is uncommon with other causes of pneumonia.
Muscle and Joint Aches
Viral pneumonia can cause muscle and joint aches, which often precede other more specific symptoms such as cough and chest pain. Respiratory syncytial virus, influenza viruses, parainfluenza viruses, rhinoviruses, adenoviruses, hantavirus, herpes simplex virus and cytomegalovirus are possible causes of viral pneumonia. Atypical pneumonias caused by Chlamydia pneumoniae, Chlamydia trachomatis or Mycoplasma pneumoniae are also associated with muscle and joint aches, which are often early symptoms of the illness.
Rash
Mycoplasma pneumoniae is the most common cause of atypical pneumonia, more commonly known as walking pneumonia. An early symptom of pneumonia caused by Mycoplasma pneumoniae is skin rash. It typically appears as pinkish-red, flat spots on the skin that fade away in 2 to 3 days. The presence of this characteristic skin rash is a good indicator that the cause of the infection may be Mycoplasma pneumonia.
