Pneumonia: what are the symptoms and who is at risk?

Haroon Siddique

What is pneumonia?

Pneumonia is an inflammation of the tissue in one or both lungs, usually caused by a bacterial infection. It causes tiny air sacs at the end of the breathing tubes in the lungs to fill up with fluid. The body sends white blood cells to the lungs to try to fight the infection, which helps kill the germs but can also make it harder for the lungs to pass oxygen into the bloodstream.

Who’s at risk?

People with a weaker immune system, whether because of age, illness or disease. Babies, infants and older people, as well as smokers and heavy drinkers, are at higher risk. People with other health conditions, including cancer, long-term heart, lung and kidney diseases and diabetes are also at increased risk, as are those whose immune system has been weakened through chemotherapy or certain medications or because they have HIV/Aids.

What are the symptoms?

They are typically similar to a flu or chest infection so would include a high temperature or fever, sweating, shivering and a cough that brings up phlegm, as well as a loss of appetite. Signs that it is more serious include breathing quickly and feeling confused or disoriented, which is mostly observed in older people. A sharp pain in the side of the chest, which becomes worse when taking a deep breath, usually means that pleurisy – an inflammation of the thin outer covering of the lung – has developed.

How serious is pneumonia?

The vast majority of people will recover from pneumonia and return to good health. In milder cases it could involve a few days or a week of being unwell and then a steady return to normality. But in severe cases it can take six months or even longer to clear and it is a leading cause of death among old and seriously ill people. In a person in poor health or with a weak immune system, untreated pneumonia can cause oxygen levels to fall so far that body tissue is starved – particularly in the heart and brain – of the oxygen it needs to function.

How is it treated?

In a healthy person, rest and plenty of water – plus antibiotics if it is bacterial – can suffice as their natural defences kick in. If symptoms are severe (more common with bacterial infections), hospital treatment will be needed. Patients will receive antibiotics and fluids through a drip, and may need oxygen to help them breathe. In very serious cases patients may be put on a ventilator.