13 Things you didn't know about the common cold

1. The term common cold is a bit of a misnomer.

Common implies that there’s a single ordinary pathogen to blame for your runny nose, coughing, and mild fatigue. Actually, there’s a huge array of viruses—­more than 200 of them—that induce colds, each with its own means of evading your body’s defences. For this reason alone, it’s unlikely that a catch-all “cure for the common cold” will ever be found.

2. As for the “cold” part, well, it’s complicated.

Scientists don’t know for sure whether low temperatures ­affect a virus’s pathogenicity, but they do believe that colds are more prevalent in winter in part because we tend to spend more time indoors, in close quarters with infected people and surfaces.

3. On top of this, sucking up dry winter air dries out the protective mucus that lines your nasal cavities.

When that happens, your body can’t do its job of catching potentially dangerous microbes before they reach your respiratory system. “The body fights back by secreting more mucus to mechanically flush out the virus,” says ­Evangeline Lausier, MD, an assistant professor at Duke Integrative Medicine in Durham, North Carolina. So don’t blame your runny nose on the cold: that’s your own body telling you it’s fighting back! (You can help your mucus win this fight by drinking lots of fluids.)

4. We get colds more often than we might realise.

Adults suffer an average of two to three each year, and some children get eight or more. They’re costly too. In the US, a 2012 survey found that colds decreased productivity by a mean of 26 per cent. Another survey estimated the total cost of lost productivity to be almost £20 billion each year.

5. That said, the best cold medicine is free: rest.

When you get sick, your body doesn’t want to do anything other than tackle the virus. If you do ignore the symptoms and go about your normal routine, the cold can have an even more negative impact on your health—and your brain. In a study of nearly 200 people published in Brain, Behavior, and Immunity, researchers found that those with colds reported poor alertness, a negative mood, and psycho­motor slowing—their thought processes were muddied, and their reaction times were slower than those of healthy folks.

6. But try not to rest while lying flat on your back.

That can make things worse because gravity may cause the congestion in your nasal passages to drip down your throat, making it sore and causing a cough. Coughing while lying flat isn’t very comfortable, and it can keep you awake. Instead, prop yourself upright with pillows to “reduce the cough receptor irritation in the back of the throat,” Dr Lausier says. This can also help move that mucus along and make it easier for you to breathe.

7. Another cost-free way to get better quicker?

Find a caring friend to nurse you. A 2009 study from the University of Wisconsin-Madison showed that patients who rated their doctors with a perfect score on an empathy questionnaire were sick one day less than patients with less sensitive doctors. Patients with the most empathetic doctors also showed double the levels of IL‑8, a protein molecule the body releases to fight colds.

8. Although your body needs rest, Dr Lausier says an excellent way to boost your immune system is with a bit of light exercise.

It’s not a surprise that regular exercise helps you fight back against germs. One study from the University of Washington in Seattle showed that overweight or obese post­menopausal women who exercised got fewer colds than those who didn’t. A 2014 review showed that regular moderate-­intensity exercise may help prevent a cold, but more research is needed. One explanation, according to the US National Library of Medicine, may be that exercise helps flush germs out of the lungs and airways.

9. Chicken soup might really work...

...though your mum’s special recipe isn’t the reason. In fact, most any clear soup helps because the warm liquid may ease congestion and increase mucus flow. “I think chicken soup is great for hydration—hot liquids, salt, and electrolytes,” Dr Lausier says.

10. Don’t rely on vitamin C.

In a 2013 review of 29 separate ­trials, regular vitamin C supplements failed to reduce cold incidences across the board. Huge doses to ease symptoms had small effects in some but not all studies.

11. Zinc, on the other hand, may reduce symptoms.

According to a post by Brent A Bauer, MD, on mayoclinic.org, recent studies have shown that zinc lozenges or syrup can reduce the length of a cold by one day, especially if taken within 24 hours of the onset of symptoms. “Zinc is necessary for the immune system to perform, so yes, you can definitely up the dose during the onset of a cold,” says Jonny Bowden, PhD, CNS. Of course, you should check with your doctor first to make sure it won’t interfere with any of your medications.

12. The cold virus can survive up to 24 hours or longer outside the human body.

So give your hands a good scrubbing after touching that door knob or kitchen tap at work. In fact, a small 2011 study showed that people infected with rhinovirus, the most common cause of colds, contaminated 41 per cent of the surfaces in their homes—including door knobs, TV remotes, and faucets. An hour after touching those infected surfaces, the fingertips of nearly 25 per cent of people still tested positive for a cold virus.

13. Nan was right: gargling can help, maybe even as a preventative.

In a study from Japan, some volunteers were asked to regularly gargle with water while others weren’t. After 60 days, the gargling group had a 40 per cent decrease in colds compared with the control group. To soothe a sore throat, gargle with one quarter of a teaspoon of salt mixed with eight ounces of warm water.