To date there have been 794,000 deaths from COVID in the U.S and as we continue to learn about the virus, one thing is for certain: It affects everyone differently. That said, there are a few common signs that indicate you have COVID and according to Dr. Justin Johnson, Emergency Medicine and Critical Care with Mercy Hospital, “symptoms include cough, fever, shortness of breath and to a lesser extent loss of taste/smell and loss of endurance.” The ZOE COVID Study, which is the world’s longest of study COVID-19 and is led by Professor Tim Spector, a professor of genetic epidemiology at King’s College London, lists other symptoms to be aware of. Read below to find out common symptoms of COVID—and to ensure your health and the health of others, don’t miss these Sure Signs You’ve Already Had COVID.

The ZOE COVID Study reports, “Even though headaches are a less well-known symptom of COVID-19, they are one of the earliest signs of the disease and more common than the ‘classic’ symptoms of cough, fever and loss of smell (anosmia). It’s important to remember that headaches are very common, especially as many of us are staring at screens for so long each day. So although many people with COVID-19 experience headaches, most people with a headache will not have COVID-19. Researchers have been investigating how to tell the difference between COVID and non-COVID headaches. They’ve found that COVID-19 headaches tend to:

• Be moderately to severely painful
• Feel ‘pulsing’, ‘pressing’ or ‘stabbing’
• Occur across both sides of the head (bilateral) rather than in one area
• Last for more than three days
• Be resistant to regular painkillers

We aren’t sure why COVID-19 causes headaches. It may be the virus directly affecting the brain. Or it could be related to being ill, such as dehydration or hunger caused by not eating and drinking normally. “

RELATED: I’m a Virus Expert and Here’s How to Not Catch COVID

The ZOE COVID Study states, “During the recent winter wave, we noticed that a runny nose was the second most commonly reported symptom in the app after headaches. And nearly 60% of people who tested positive for COVID-19 with loss of smell also reported having a runny nose. So while we can say that many people with COVID-19 have a runny nose, it’s more difficult to say that having a runny nose is a definitive symptom of COVID-19 since they are so common, especially in the winter.”

RELATED: 5 Life-Saving Essentials Plummeting in Supply

According to the ZOE COVID Study, sneezing happens more in patients who have been vaccinated. “Data from the ZOE COVID Study suggests that sneezing more than usual can be a sign of COVID-19 but only in people who’ve been vaccinated…Sneezing is not normally a symptom of COVID-19, and much more likely to be a sign of a regular cold or allergy. Even though many people with COVID-19 might sneeze, it’s not a definitive symptom because sneezing is so common, especially in the warmer months where people might experience hay fever.”

“Even though a sore throat is a less well-known symptom of COVID-19, it’s an early sign of the disease and reasonably common in children and adults up to the age of 65,” The ZOE COVID Study states. “People using the app have reported having a sore throat that feels similar to what you might experience during a cold or laryngitis. COVID-related sore throats tend to be relatively mild and last no more than five days. A very painful sore throat that lasts more than five days may be something else such as a bacterial infection, so don’t be afraid to contact your GP if the problem persists. It’s important to remember that sore throats are common and caused by lots of respiratory illnesses such as normal colds. So although many people with COVID-19 experience sore throats, most people with a sore throat will not have COVID-19.”

RELATED: Not Remembering This One Thing Can Be a Sign of Dementia

Data from the ZOE COVID Study shows, “A persistent cough is widely known as one of the three ‘classic’ symptoms of COVID-19, along with fever and loss of smell, although only around four in ten people who are ill with COVID-19 will have a persistent cough. In this context, persistent means coughing many times a day, for half a day or more. It can be hard to notice if you’re coughing more than usual, so make sure you’re keeping an eye on yourself and others around you. This is usually a dry (unproductive) cough, unless you have an underlying lung condition that normally makes you cough up phlegm or mucus. However, if you have COVID-19 and start coughing up yellow or green phlegm (‘gunk’) then this may be a sign of an additional bacterial infection in the lungs that needs treatment. Coughing is a major way that coronavirus spreads. If you have a cough that could be COVID-19 you must get a test and self-isolate. Whether you’re ill or not, always make sure you cover your coughs – for example by coughing into your elbow – and wear a face covering or mask to protect others.”

Fever is a common symptom of the virus, according to the ZOE COVID Study. The COVID Symptom Study app found that around four in ten people reporting symptoms of COVID-19 have a high temperature (fever). Fever is not necessarily a bad thing. It’s a normal response to infection, as raising your body temperature helps your immune system fight it off.

If you’re under 65, having a temperature over 37.8°C is likely to be a sign of COVID-19. If you’re over 65 or very thin, your normal body temperature is likely to be lower, so a reading over 37.4°C should be considered to be a potential symptom. You can measure your temperature at home using a thermometer – read our blog post to find out how. An in-ear thermometer is best but an oral (mouth) thermometer is fine. Other devices like smartphones may not be so reliable.

If you don’t have a thermometer, the key sign to look out for is feeling hotter than usual, particularly on your chest or back. You may also be shivery or have chills. It’s also important to know that there is no one ‘normal’ body temperature, so get in the habit of checking yours regularly to know what’s usual for you. Body temperature can also be affected by hormones, for example in women who are going through the menopause.

RELATED: The #1 Reason for Obesity, According to Doctors

The ZOE COVID Study says, “Data from millions of users of the ZOE COVID Symptom Study app has shown that loss of smell can be a symptom of COVID-19. Here’s how to spot it and what it feels like.

What is anosmia like in COVID-19?

The ZOE COVID Symptom Study app found that many people infected with coronavirus lose their sense of smell (anosmia) and/or taste.

Some people using the app have also reported that their sense of smell didn’t go completely, but changed with COVID-19 infection so that things smelled markedly differently to before.

If you have anosmia or a change in your sense of smell, you may notice that you can’t smell strongly scented things like coffee or flowers (or candles!). You may also notice that food tastes different from normal or seems tasteless (dysgeusia).” 

RELATED: Everyday Habits That Make You Older, According to Science

Follow the public health fundamentals and help end this pandemic, no matter where you live—get vaccinated ASAP; if you live in an area with low vaccination rates, wear an N95 face mask, don’t travel, social distance, avoid large crowds, don’t go indoors with people you’re not sheltering with (especially in bars), practice good hand hygiene, and to protect your life and the lives of others, don’t visit any of these 35 Places You’re Most Likely to Catch COVID.