Pneumonia means that there is an infection or inflammation in the lung tissue. It can be caused by a lot of different micro-organisms - viruses, bacteria, fungi and parasites that are too small to see - but it can also be caused by corrosive chemicals breathed into the stomach or toxic gases from a fire.

Pneumonia is an inflammation of the lung tissue. It is usually due to infection. Pneumonia tends to be more serious than bronchitis. (Bronchitis is an inflammation or infection of the large airways - the bronchi.) Sometimes bronchitis and pneumonia occur together which is called broncho-pneumonia.

Causes

Pneumonia usually starts when you breathe the germs into your lungs. You may be more likely to get the disease after having a cold or the flu. These illnesses make it hard for your lungs to fight infection, so it is easier to get pneumonia. Having a long-term, or chronic, disease like asthma, heart disease, cancer, or diabetes also makes you more likely to get pneumonia.

Bacterial pneumonias tend to be the most serious and, in adults, the most common cause of pneumonia. The most common pneumonia-causing bacterium in adults is Streptococcus pneumoniae (pneumococcus).

Symptoms

People with infectious pneumonia often have a cough producing greenish or yellow sputum, or phlegm and a high fever that may be accompanied by shaking chills. Shortness of breath is also common, as is pleuritic chest pain, a sharp or stabbing pain, either experienced during deep breaths or coughs or worsened by it. People with pneumonia may cough up blood, experience headaches, or develop sweaty and clammy skin. Other possible symptoms are loss of appetite, fatigue, blueness of the skin, nausea, vomiting, mood swings, and joint pains or muscle aches.

The most common symptoms of pneumonia are shortness of breath; chest pain, especially when breathing in; coughing; shallow, rapid breathing; and fever and chills. Coughs usually bring up mucus, also called sputum. The sputum may even be streaked with blood or pus. In serious cases, the patient’s lips or nail bed will appear blue due to lack of oxygen.

Treatment

If you have community-acquired pneumonia, your doctor will prescribe you antibiotics immediately, often prior to tests on the phlegm sample. Antibiotics treat pneumonia caused by bacteria. Antibiotics are usually given straight away as bacterial infections are the most common cause of pneumonia and antibiotics are generally very effective. It is usually safe to assume that the infection will respond to standard antibiotics such as amoxicillin. Generally for chest infections you should take antibiotics for about seven days and you must complete the full course.

If you have severe pneumonia, you'll be hospitalized and treated with intravenous antibiotics and put on oxygen. If you don't need oxygen, you may recover as quickly at home with oral antibiotics as in the hospital, especially if you have access to qualified home health care. Sometimes you may spend three or four days in the hospital receiving intravenous antibiotics and then continue to recover at home with oral medication.