There are two main categories of pneumonia based on how the disease was contacted. There is community acquired pneumonia and hospital acquired pneumonia. If a person suffers from the first category of pneumonia, then the diagnosing process can be very simple, based only on a physical examination and the medical history of the patient. However, this is only if his/ her pneumonia is mild to moderate. On the other hand, if a person suffers from hospital acquired pneumonia, diagnosing the condition can be very difficult.

The first step when diagnosing pneumonia is to know the personal as well as medical history of the patient. Some of the important aspects that the pneumonia patient must be sure to tell his/ her doctor are:

- if he/ she has suffered from any recent respiratory infection or if he/ she had such an infection;

- if you have been in contact with anybody that has pneumonia or suffers from other problems of the respiratory system;

- you should also tell your doctor if you are a smoker, or if you use any drugs or drink alcohol; even if you have quite, you should still tell your doctor because any information is very important in diagnosing pneumonia;

A second step in diagnosing pneumonia is a physical exam. The most used and also very important tool that is used to diagnose pneumonia is the stethoscope. With the help of this instrument, your doctor can listen to the sounds of your chest. The most suggestive sounds that can indicate pneumonia are:

- rales: a bubbling sound; if these reales are heard on one side of your chest or when you are lying down, then they indicate that you have pneumonia;

- rhonchi: unusual rumblings that indicate the presence of a very thick fluid;

Another test used to diagnose pneumonia is percussion. Your doctor will tap your chest and if a dull thud is heard instead of a drum like sound, then you probably are suffering from pneumonia. In this case further tests must be done to proper diagnose pneumonia.

This is the easy part, because this is the way people that have community acquired pneumonia are diagnosed. However, when it comes to people that are possible suspects of hospital acquired pneumonia, then diagnosing this condition ca be very difficult. The main reason for this is that all these possible pneumonia patients have similar signs.