Cold, Flu, or Coronavirus? Here’s Exactly What to Do If You Feel Sick

Rachael Gonzalez, MD
Medically Reviewed
March 9, 2020

Aside from all of the unknowns about the novel coronavirus (COVID-19), one of the most worrisome things for the public are the reported similarities to the seasonal cold and flu. The truth is, in some cases, it can be difficult to tell, which is why mild cases of coronavirus may go undetected. It’s important to have a relationship with your primary care physician, who you can check in with easily if you need help differentiating symptoms. Here’s how the illnesses differ and what to do if you have symptoms.

How symptoms of COVID-19 differ from the cold and flu

Coronaviruses are not new. Some coronaviruses cause things like the common cold while others can cause more serious infections like SARS. However, the specific coronavirus making headlines today is new to humans which is why health organizations are following it closely.

Many viral infections have stereotypical symptoms, ranging from fever, mucus production, body aches and cough to shortness of breath and fatigue .

Common cold

Colds come on gradually and the most common symptoms are a stuffy nose, sore throat, and sneezing. They sometimes also include a cough and fatigue. Fever and headaches are rare .

Seasonal flu

Symptoms of the flu are abrupt and can include fever or feeling chills, cough, sore throat, runny or stuffy nose, muscle or body aches, headaches, and fatigue, according to the CDC . Some people may also have vomiting or diarrhea, though it’s more common in children.


The CDC says the three hallmark symptoms to keep an eye out for are fever, dry cough, and/or shortness of breath. More recent studies have indicated that at the early stages of the infection, some people experience loss of appetite or sense of smell and diarrhea.

The vast majority of patients with more mild cases of COVID-19 will experience it as one of the worst colds or flu-like illnesses they have ever had.

Immunocompromised individuals are more at risk for developing a more severe version of COVID-19. They may not be able to mount a strong enough initial immune response and in these instances are at risk of dire outcomes due to the massive inflammation and tissue damage triggered by the virus.

Your body’s reaction to a virus

Ready to get technical? Here’s the science behind what’s going on in your lungs when your immune system reacts to a virus: viral replication, immune hyperreactivity, and lung tissue destruction. Not all people infected with a virus will experience all three of these phases.

First, your body will produce mucus in an attempt to contain or trap the virus. COVID-19 also tends to negatively affect the lungs’ system of hair cells that move debris, mucus and infectious agents out of the body.

The second phase of the infection involves overstimulation of the body’s defenses against viral infections. Research from The Lancet shows us that with coronavirus there is a marked upswing in the production of infection-fighting chemicals produced by the body’s immune cells called cytokines. These cytokines in turn signal immune cells to enter the picture and try to engulf the virus, resulting in cell death and increased inflammation.

Viruses with high replication rates (like the novel coronavirus) often overwhelm immune responses leading to local tissue destruction and depletion of infection-fighting cells. Cytokines, proteins secreted by certain immune cells, also can travel via the circulatory system to other organs such as the kidneys, liver, and small intestine. Dramatic increases in cytokines are referred to as a cytokine storm and this appears to be a distinguishing feature of severe respiratory viruses vs lesser viruses like the common cold.

Sometimes, you may be a carrier of a virus but have no symptoms (meaning you can unsuspectingly pass it on.)

What to do if you’re sick

If you get sick with fever, cough, or shortness of breath, stay at home and alert your primary care provider. If your symptoms tend to stabilize—meaning you continue to have cough, low-grade fever, and body aches but no significant shortness of breath, stay home, rest, and support your immune system as it fights this viral illness.

With COVID-19, reports from hospitalized cases indicate that the potential for clinical deterioration appears to peak in the second week of illness. Patients may develop shortness of breath—a major indicator of respiratory compromise.

If you develop severe symptoms (such as but not limited to persistent fever >102, difficulty breathing at rest or become confused or difficult to arouse) or are in a high-risk group and develop shortness of breath, call 911 or go to the nearest emergency room after calling ahead for safe arrival instructions.

Can I get tested for coronavirus?

Currently, diagnostic testing for COVID-19 is being performed at state public health laboratories and The Centers for Disease Control (CDC), but new at-home testing options are emerging. The CDC has broadened their guidelines for coronavirus testing so that anyone who is symptomatic can be tested, but priorities will be given to healthcare workers and those in higher-risk categories or with more severe disease. These recommendations are changing frequently so use the CDC website for the latest information.

While testing will become more widely available, that doesn’t mean everyone with the first signs of a cold should be tested for coronavirus. The number of tests continue to be limited and getting tested too early could divert the much-needed tests away from seriously ill people. Your doctor will help you determine if you should be tested.

If you test positive, what happens?

Your doctor will decide a course of treatment based on the severity of your symptoms.

If your condition is relatively stable, you may be able to stay at home and recover. You’ll need to strictly isolate yourself from other people in your home and they will need to have access to appropriate, recommended personal protective equipment (at a minimum, gloves and a face mask.) Everyone will need to adhere to precautions recommended as part of home care or isolation, such as good hygiene. You’ll also need access to food and other necessities.

Critically ill patients will be managed in the hospital. Current recommendations are that people can be released from quarantine 72 hours after symptom resolution.

Rachael Gonzalez, MD

Credentials: Board Certified Physician in Family and Integrative Medicine

Training Institutions: Harvard College • University of California San Diego School of Medicine • Family Medicine Residency at Riverside Medical Center in Riverside California • Institute for Functional Medicine • Academy of Integrative Health and Medicine • The Women’s Integrative Health Institute

Clinical Interests: Thyroid Management • Menopause Management including bioidentical HRT • Adrenal Issues • Digestive Disorders • Asthma • Allergies • Autoimmune conditions • Migraines • Metabolic syndrome • Diabetes • Preventive Cardiology • Advanced Lipid Analysis & Management • Nutrigenomics

Previous Positions: Staff physician in various healthcare organizations in San Antonio, Texas and Renton, Washington • Director of Urgent Care Services in San Antonio • Owned and operated Paradigm Family Medicine which provided functional and conventional medicine services in a high touch, high tech environment • Received NCQA recognition for Diabetes and was recognized as a Patient Centered Medical Home.

What I’m most excited to bring to Parsley Health members: I’m most excited to work in a vibrant collaborative environment where everyone authentically cares and is committed to enhancing the lives and relieving the burden that chronic illness has had on our patient members. I’m most excited to bring my curiosity and love of puzzles and combine these with the art of storytelling to help patients unravel the mysteries of their health issues.

Ask me about: My love of cooking and culinary nutrition

Most likely to find me: In my favorite Pilates class, weight training, or getting lost in a good book

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