In pre-pandemic days, if you got a sniffle and a headache, you might dismiss it as an ordinary cold and carry on as normal, even if you felt a little rough around the edges.
But as these symptoms are now some of the primary indicators of Covid-19 too, how can you be certain you have just caught a cold?
Experts also believe cold-like symptoms are more likely to be present in people who have been vaccinated.
Christina Marriott, chief executive of the Royal Society for Public Health said: “Growing evidence shows that people who’ve received two doses of the vaccine typically present with less severe symptoms, such as headache, runny nose, sneezing, sore throat and loss of smell.
“It’s important for people who’ve been fully vaccinated to stay vigilant for cold-like symptoms, and get tested if they’re living or working around people who are at greater risk from the disease.”
Professor Irene Petersen, a professor of epidemiology and health informatics at University College London, added: “A runny nose and headache are symptoms of many infections, but may also be the first symptoms – and only symptoms – of Covid.
“Therefore, if you have these symptoms, I’d encourage you to use lateral flow tests [LFT] for a couple of days.
“The first few LFTs may be negative, but if you have Covid the tests are likely to become positive within a couple of days. Also, if you know other people around you have Covid, the likelihood your runny nose and/or headache is also Covid is much higher.”
Since 1 April, most people now need to pay for LFTs but anyone who believes they have contracted the coronavirus is advised to do so and be prepared to isolate for five days in the event of a postive result.
They are available at Boots and Superdrug from £1.99 and the government has also published a list of approved providers here.
You can check out the very latest NHS Covid advice here.
Meanwhile, here are some indicators that point to whether your condition might indicate Covid or just an ordinary cold.
A headache is one of the newer symptoms of Covid listed by the NHS.
Headaches are one of the earliest signs, according to the ZOE study, and are more common than the classic symptoms of cough, fever and loss of smell.
ZOE research found that Covid headaches tend to be moderately to severely painful, can be “pulsing”, “pressing” or “stabbing”, occur across both sides of the head rather than in one area, may last for more than three days and tend to be resistant to regular painkillers.
A blocked or runny nose is also a new addition to the NHS symptoms list.
Last winter, the ZOE study found that a runny nose was the second most commonly reported symptom after headaches, with nearly 60 per cent of people who tested positive for Covid with loss of smell also reporting having a runny nose.
But now the data indicates that the prevalence of the disease is the most significant factor. So, when Covid rates are high, the chances of a runny nose being due to the virus are also high.
The study also stresses that when Covid rates are low, a runny nose is less likely to indicate the sufferer has caught the coronavirus and is more likely to be due to a cold or even an allergy.
It concludes that while many people with Covid may report a runny nose, it is difficult to call it a definitive symptom as it is so common, especially during winter.
Sneezing is not recognised as an official symptom by the NHS, but the ZOE study found that sneezing more than usual can be a sign of Covid in people who have been vaccinated.
However, it stresses sneezing is much more likely to be a sign of a cold or an allergy.
It says that even though many people with Covid might sneeze, “it’s not a definitive symptom because sneezing is so common”.
The NHS has added a sore throat to the official list of symptoms.
Many people with Covid have reported via the ZOE app that they have a sore throat that feels similar to one you might experience you get when you have a cold or laryngitis.
Covid-related sore throats tend to be mild and last no more than five days so a very painful one that lasts longer is likely to be something else. If it persists, you should contact your GP.
According to ZOE data, almost half of people who have been ill with Covid reported having a sore throat, although this is more common in adults aged between 18-65 than the elderly or those under 18.
Loss of smell
This continues to be the strongest indicator of Covid infection, regardless of a person’s age, sex or illness severity.
While people who have Covid might not lose their sense of smell completely, it may change, so you may not be able to smell strongly-scented things, and your sense of taste may be affected too, so food may taste different or seem tasteless.
A stubborn cough is widely agreed to be one of the three main symptoms of Covid but, according to the ZOE study, only around four in 10 people who are ill with the virus will experience this.
In this context, “persistent” means coughing many times a day, “for half a day or more”.
A Covid cough is usually a dry cough, compared with a chesty one that brings up phlegm or mucus and that may indicate a bacterial infection.
A persistent cough tends to arrive around a few days into the illness and usually lasts for around four or five days.