'That is when you're going to pass it on' - Dr Amir reveals when you're most contagious with a cold

We’ve all been in an office or on a train where someone is coughing all over the place and obviously contagious with a cold. We’ve probably done it ourselves, too, because staying at home isn’t always an option when you have a cold or the flu.

However, at a time of year when we’re all susceptible to catching and spreading germs and viruses, woman&home’s resident GP, Dr Amir Khan, has been advising against complacency. Speaking to co-host Cherry Healey on their No Appointment Necessary podcast, Dr Khan says staying at home when you first notice symptoms of a cold or the flu isn’t dramatic - it's actually the most responsible thing to do.

“We’re usually more infectious in the two or three days leading up to your first symptoms, so before you even know you’ve got it. So when you’re thinking ‘I’ve got a sore throat, but I can do this, I can go into work’ - that is when you’re going to pass it on," he says.

When Cherry suggests many of us don’t want to be seen as a “big faker” by colleagues or friends if we cancel plans and stay at home, Dr Khan answers that “no one will thank you for giving them a cold or the flu”. It’s true. “Pushing through a cold doesn’t make you a hero… it makes everyone else sick,” says the caption for the podcast’s Instagram post.

“I would rather see more patients and my colleagues stay at home because I don’t want to be ill,” the doctor says.

In an ideal world, we should stay at home from the moment we start to feel unwell or notice a slight symptom, he says. “Don’t come into work, stay at home, rest until you’re feeling better.”

However, the doctor also notes that not everyone has the option to take a duvet day. If you're self-employed, not entitled to sick pay, or have caring responsibilities, it's much harder. If this is you, the best option is try to stay as healthy as possible, and we’ve outlined some ways below.

What else can I do to avoid catching a cold?

Ventilation, ventilation, ventilation, says Dr Khan. "These viral particles linger in the air. If you open a window, if you open a door, and if you can afford to, get an air filter with a HEPA filter in there. That will filter out these viral particles, and you're much less likely to breathe them in," he says in another episode.

Other tips from the experts

• Ask people to let you know if they’re ill: The best way to stay healthy is to keep away from ill people. If you’re due to meet a friend who’s contagious with a cold or you are, postpone it to a day when they’re better. Neither of you will thank the other one if a coffee date turns into a few days on the sofa.
• Stay away from crowded places: Public transport, gyms, and shops can all be places where you might catch an illness, as well as your workplace. Choose a quieter time of day to use or visit these places to limit your contact with other people.
• Use hand sanitiser and disinfectant spray: If you’ve been somewhere busy, wash your hands and use hand sanitiser afterwards to get rid of any germs you’ve touched.
• Eat a healthy, balanced diet: Eating plenty of immunity-boosting foods rich in vitamins and nutrients will help keep your immune system healthy and help you fight off germs.
• Consider taking supplements: Dr Amir Khan has previously told us the best way to shorten a cold is to take zinc. Vitamins C and D help support our immune systems and keep viruses at bay as well.
• Have the flu jab: This vaccine is one of the key ways we can lower our risk of catching flu and spreading it. Check if you're eligible for a free one on the NHS website.