Before the COVID-19 pandemic, waking up with a runny nose, congestion, sneezing, body aches, sore throat, cough, and maybe a mild fever meant you likely had a cold. Rest, hydration, and over-the-counter decongestants were probably all you needed to ride out your illness.
But these days, it isn’t as easy to dismiss upper respiratory symptoms as “just a cold.” You may have COVID-19. Or the issue may be flu, strep throat, or another condition that might warrant medical attention.
How do you know whether you have a cold or something else?
“There’s no one specific sign that what you have isn’t a cold,” says Erica Hinteregger, a senior physician assistant specializing in internal medicine at the Brigham and Women’s Hospital in Boston. A dozen shared symptoms could signal a cold, COVID-19, flu, respiratory syncytial virus (RSV), seasonal allergies, or something else, making it nearly impossible to know what you have without testing, a doctor’s visit, or both.
While a cold won’t typically send you to the emergency room, respiratory infections of all kinds can sometimes lead to serious illnesses, such as pneumonia (infection of the lung’s air sacs). Other potential complications include sinus infection (also known as sinusitis, this is an inflammation of the cavities around the nasal passages) and bronchitis (inflammation of the lining of the bronchial tubes, which carry air to and from the lungs), says Elina Jerschow, MD, a professor of medicine and chair of the division of allergy at Mayo Clinic in Minnesota.
Wondering if there are any clues at all to help you know if your symptoms are not “just” a cold? Worried because you keep getting sick and think your immune system might be sending up a red flag? Here are some symptoms to pay attention to.
1. High Fever
A temperature that is higher than normal (97.5 to 98.9 degrees F) lets you know your body is fighting an infection. A high fever is typically not a cold or allergy symptom but could point to COVID-19, flu, strep throat, or another respiratory illness.
“Flu typically comes with a fever greater than 101 degrees F, and chills and body aches, which tend to start immediately, distinguishing it from a cold,” Hinteregger says. “A fever with a sore throat but no other cold symptoms can point to strep throat, a bacterial infection.”
Contact your healthcare provider if a baby under 3 months old has a fever, or if a fever is accompanied by a seizure or other signs of serious illness such as lethargy, irregular breathing, stiff neck, or confusion, per Johns Hopkins School of Medicine. Seek medical attention if a fever is very high or lasts over three days.
2. Severe Headaches
A headache is pain or discomfort in the head or face. Intense headaches are a common flu symptom and frequently accompany COVID-19 but are rarely a sign of a cold, according to the Cleveland Clinic. Some headaches could be related to a sinus infection. It’s best to seek medical care if your headache persists.
3. Ear Pain, Barking Cough
According to the Centers for Disease Control and Prevention (CDC), fever, ear pain, irritability, and decreased appetite can be signs of RSV or human parainfluenza viruses (HPIVs). While anyone can get infected, these viruses can lead to complications in infants and young children, older adults, and people with weakened immune systems, Hitteregger says.
In children, the viruses can cause pneumonia, croup (infection of the upper airway), bronchitis, and bronchiolitis (infection of the smallest airways in the lungs), and in extreme cases can be life-threatening. Danger signs include a barking cough, hoarseness, noisy or high-pitched sounds with breathing, and wheezing.
In adults, upper respiratory infections and bronchitis are the most common illnesses caused by RSV and HPIVs; symptoms may include fever, runny nose, cough, and sore throat.
4. Watery Eyes, Itchy Nose
Seasonal allergies can feel like a cold because they can cause sneezing, runny or stuffy nose, and coughing, but rarely result in a fever. When allergies do cause a fever (hence the name hay fever), your temperature will likely remain relatively low, Dr. Jerschow says.
If you have watery eyes, or an itchy nose or mouth at certain times of the year, your body is probably fighting allergens, including pollen from trees, weeds, and grasses. Jerschow says a clue is that “cold season is usually for colds and warm season for allergies!” Seasonal allergies may last several weeks, and can be treated with antihistamines, nasal steroid sprays, and decongestants.
5. Sinus Headache and Facial Pressure
When a cold, flu, or allergy progresses, nasal cavities can become swollen, and excess fluid in the sinuses can breed germs, leading to sinusitis or rhinosinusitis — viral or bacterial sinus infections that can cause sinus headache or facial pressure.
Symptoms may differ depending on whether the cause is bacterial or viral, and often linger even after other upper respiratory issues are gone.
6. Mucus in Unusual Amounts or Colors
Mucus, the watery gel that protects the nose and sinuses from pollen, dust, and other irritants, comes in an array of hues.
Here’s a guide from Penn Medicine to what the color of your mucus may mean:
- Clear, watery mucus, in excess amounts, can signal a seasonal allergy as your immune system works to trap pollen, dust, or other irritating substances and expel them from the body.
- Thick, white mucus can be a sign of your immune system doing its job of capturing and expelling viruses that have infiltrated the nose and sinuses.
- Green or yellow mucus can be a normal part of the immune system’s response to a cold. The yellow color comes from dead white blood cells; mucus can turn green when it’s full of many dead white blood cells and other cellular bits.
- Red or pink snot is a mix of mucus and blood; your nasal passages may bleed slightly due to the irritation of blowing or rubbing your nose or even the effects of dry air.
- Brown or orange snot can be a combination of mucus and dried blood, cigarette smoke, or dirt. In the most serious cases brown snot can signify bronchitis.
- Black mucus can be a combo of mucus and dried blood although in some cases it can signal a fungal infection, particularly among people who are immunocompromised.
Talk to a healthcare provider if you’re concerned about any changes in the color of your mucus or if these changes occur alongside other symptoms such as difficulty breathing, dehydration, pain, or other cold symptoms that last longer than 10 days.
7. Muscle Aches and Debilitating Fatigue
Debilitating fatigue and body aches (as well as green or yellow mucus when blowing your nose or coughing, high fever, night sweats, and headaches) may be signs of sinusitis, bronchitis, or pneumonia. Fatigue and body aches are also common symptoms of COVID-19.
According to the Cleveland Clinic, some of these symptoms can also point to postural orthostatic tachycardia syndrome (POTS), a treatable but misunderstood disease that affects the body’s circulation. It can feel like having the flu but can also reveal itself in other symptoms such as chest pain, racing heart rate, sweating, and difficulty breathing. If you think you may have POTS, discuss it with your medical provider.
8. Diarrhea, Vomiting, Nausea, or Stomach Pain
You typically wouldn’t have any of these symptoms with a cold but might experience them with the flu or COVID-19. If you’re vomiting and have diarrhea — often simultaneously — it could also be the dreaded norovirus, the CDC says. The easily transmissible virus causes inflammation of the stomach or intestines (acute gastroenteritis) causing symptoms lasting between one and three (long and highly unpleasant) days.
You can get norovirus, commonly known as stomach flu, by touching an infected surface, then putting your hands in your mouth, ingesting contaminated food or liquid, or getting tiny particles of vomit or feces in your mouth. The best thing to do is lay low, stay hydrated, and let it pass. It’s a good reason to stay home and binge Netflix.