How your body does battle – fighting the common cold

Director of Clinical Strategy, Bupa
14 December 2015
Woman blowing her nose

When you’re fed up of blowing your nose, struggling to breathe and feeling generally terrible because of a cold, it’s easy to blame the virus for causing it all. You may be surprised to learn that it’s not the cold as such that’s making you feel so rotten. It’s how your body responds to the virus that causes all those horrible symptoms.

The common cold – what it is?

The common cold is an illness caused by a virus, most often the rhinovirus. Viruses are tiny parasites. They depend on cells from plants and animals – including us – to stay alive and reproduce. This means that when a virus enters your body, it invades and takes over your cells, and directs them to produce more virus.

You’ll know you’ve got a cold by the symptoms that go with it: a stuffy and snotty nose, sore throat, cough and sneezing.

How your immune system works

This is where your immune system steps up to do battle. Your immune system is designed to detect and destroy harmful cells that invade your body. When the cold virus attacks, your immune system reacts by flooding the area with white blood cells and chemical messengers. You can think of the white blood cells as ‘defender cells’. These defender cells can kill harmful cells with three impressive battle tactics:

  • some swallow up the harmful cells and kill them
  • some make antibodies that stick to the cells – this identifies the harmful cells so they can be attacked
  • some destroy the harmful cells directly

Yet while your immune system is helping you out, the downside is that the white blood cells trigger the symptoms that cause you to feel poorly. Here’s an example.

Your nose feels blocked because white blood cells have rushed to the blood vessels in your nose and caused them to swell, making it harder to breathe. Snot is also the result of the white blood cells doing battle in your nose to get rid of the virus.

In a nutshell, the white blood cells are helping you get better – your immune system is working hard to kill off the virus. The catch is that you feel rotten and gross in the process. Symptoms can last for a number of days.

Once your immune system has encountered a virus, it can react in time to stop you catching the same illness again. This is called developing immunity. So why do we keep catching colds? The reason is that colds are caused by lots of different types of virus – far too many for us to be able to develop immunity to all them. They also mutate very fast and new strains are appearing all the time. They are very clever!  

So is there a way to outsmart them?

How to prevent catching a cold this winter...

It’s not possible to guarantee you won’t catch a cold. Most adults will probably get about two colds a year. But there are definitely things you can do to minimise the chances. Here are my three top tips for staying well and warm this winter.

1. Wash your hands regularly with soap and hot water.

2. Keep your immune system strong by looking after yourself. Eat well, and make sure you get enough sleep and exercise.

3. If you do catch a cold, drink plenty of water, gargle with salt water to help a sore throat, and try nasal drops or sprays to clear up congestion. Take paracetamol, ibuprofen or aspirin to relieve pain.

Even healthy people become unwell sometimes. Health insurance can help you get prompt access to the treatment and support you need to help you get back on the road to recovery. Learn more with our useful guide to understanding health insurance.

Dr Lizzie Tuckey
Director of Clinical Strategy, Bupa

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