I didn't think being cold was a cause for pneumonia..
Causes of pneumonia
The micro-organisms that cause pneumonia may be present in your body for some time before you become ill. Alternatively you may breathe in droplets that are in the air from other people coughing and sneezing. You may also breathe in organisms from the environment (for example in Legionnaire's disease, a form of pneumonia caused by Legionella pneumophilia).
The most common bacterium that causes community-acquired pneumonia is Streptococcus pneumoniae - this is called pneumococcal pneumonia. Bacteria that commonly cause hospital-acquired pneumonia (also called nosocomial pneumonia) include Haemophilus influenzae, Klebsiella pneumoniae and Staphylococcus aureus. Viruses, including the influenza (flu) virus can also cause pneumonia.
Pneumonia may also be caused by inhaling substances, for example, vomit, a peanut, a chemical or smoke. It can also occur from allergy, for example. 'Farmers lung' is from an allergy to mouldy hay.
If children, particularly those under school age, get pneumonia, it's more often because of a virus than bacteria.
You are more likely to get pneumonia if you:
* are in poor health
* are over 65 or very young
* smoke (smoking damages your lungs and therefore makes it easier to get an infection)
* drink too much alcohol
* have a long-term illness, such as cancer - particularly if this affects your body's ability to fight infection
* have a weakened immune system, for example if you have HIV/AIDS