Listen to this article - English & Spanish
Learn About COVID-19
What is the difference between Influenza (Flu) and COVID-19?
Influenza (Flu) and COVID-19 are both contagious respiratory illnesses, but they are caused by different viruses. COVID-19 is caused by infection with a new coronavirus (called SARS-CoV-2) and flu is caused by infection with influenza viruses.
There are some key differences between flu and COVID-19. COVID-19 seems to spread more easily than flu and causes more serious illnesses in some people. It can also take longer before people show symptoms and people can be contagious for longer. Another
important difference is there is a vaccine to protect against flu. There is currently a limited supply of COVID-19 vaccine in the United States, but supply will increase in the weeks and months to come. The best way to prevent infection is to avoid
being exposed to the virus. More information about differences between flu and COVID-19 is available in the different sections below.
Because some of the symptoms of flu and COVID-19 are similar, it may be hard to tell the difference between them based on symptoms alone, and testing may be needed to help confirm a diagnosis. Flu and COVID-19 share many characteristics, but there are
some key differences between the two.
While more is learned every day, there is still a lot that is unknown about COVID-19 and the virus that causes it. This page compares COVID-19 and flu, given the best available information to date.
Flu Symptoms
Influenza (flu) can cause mild to severe illness, and at times can lead to death. Flu is different from a cold. Flu usually comes on suddenly. People who have flu often feel some or all of these symptoms:
- fever* or feeling feverish/chills
- cough
- sore throat
- runny or stuffy nose
- muscle or body aches
- headaches
- fatigue (tiredness)
- some people may have vomiting and diarrhea, though this is more common in children than adults.
*It’s important to note that not everyone with flu will have a fever.
What are the emergency warning signs of flu?
People experiencing these warning signs should obtain medical care right away.
In children
- Fast breathing or trouble breathing
- Bluish lips or face
- Ribs pulling in with each breath
- Chest pain
- Severe muscle pain (child refuses to walk)
- Dehydration (no urine for 8 hours, dry mouth, no tears when crying)
- Not alert or interacting when awake
- Seizures
- Fever above 104°F
- In children less than 12 weeks, any fever
- Fever or cough that improve but then return or worsen
Worsening of chronic medical conditions
In adults
- Difficulty breathing or shortness of breath
- Persistent pain or pressure in the chest or abdomen
- Persistent dizziness, confusion, inability to arouse
- Seizures
- Not urinating
- Severe muscle pain
- Severe weakness or unsteadiness
- Fever or cough that improve but then return or worsen
Worsening of chronic medical conditions
These lists are not all inclusive. Please consult your medical provider for any other symptom that is severe or concerning.
Symptoms of Coronavirus
People with COVID-19 have had a wide range of symptoms reported – ranging from mild symptoms to severe illness. Symptoms may appear 2-14 days after exposure to the virus. People with these symptoms may have COVID-19:
- Fever or chills
- Cough
- Shortness of breath or difficulty breathing
- Fatigue
- Muscle or body aches
- Headache
- New loss of taste or smell
- Sore throat
- Congestion or runny nose
- Nausea or vomiting
- Diarrhea
- This list does not include all possible symptoms. CDC will continue to update this list as we learn more about COVID-19.
Older Adults
At greater risk of requiring hospitalization or dying if diagnosed with COVID-19
What you need to know
- Risk for severe illness with COVID-19 increases with age, with older adults at highest risk.
- Certain medical conditions can also increase risk for severe illness.
- People at increased risk, and those who live or visit with them, need to take precautions to protect themselves from getting COVID-19.
Increased Risk of Hospitalization or Death
Age Increases Risk for Severe Illness
The risk for severe illness with COVID-19 increases with age, with older adults at highest risk.
For example, people in their 50s are at higher risk for severe illness than people in their 40s. Similarly, people in their 60s or 70s are, in general, at higher risk for severe illness than people in their 50s. The greatest risk for severe illness from
COVID-19 is among those aged 85 or older.
Severe illness means that a person with COVID-19 may require:
- hospitalization,
- intensive care, or a
- ventilator to help them breathe, or
they may even die.
Age Increases Risk for Hospitalization
Older adults are at greater risk of requiring hospitalization or dying if they are diagnosed with COVID-19. As you get older, your risk of being hospitalized for COVID-19 increases.
Compared to younger adults, older adults are more likely to require hospitalization if they get COVID-19
| Hospitalization | Death | |
|---|---|---|
| 18-29 years | Comparison Group | Comparison Group |
| 30-39 years | 2x higher | 4x higher |
| 40-49 years | 3x higher | 10x higher |
| 50-64 years | 4x higher | 30x higher |
| 65-74 years | 5x higher | 90x higher |
| 75-84 years | 8x higher | 220x higher |
| 85+ years | 13x higher | 630x higher |
Certain Medical Conditions Can Increase Risk
Other factors can also increase your risk for severe illness, such as having certain underlying medical conditions. By understanding the factors that put you at an increased risk, you can make decisions about what kind of precautions to take in your daily life.
If you have an underlying medical condition, you should continue to follow your treatment plan:
- Continue your medicines and do not change your treatment plan without talking to your healthcare provider.
- Have at least a 30-day supply of prescription and non-prescription medicines. Talk to a healthcare provider, insurer, and pharmacist about getting an extra supply (i.e., more than 30 days) of prescription medicines, if possible, to reduce your trips to the pharmacy.
- Do not delay getting emergency medical care because of COVID-19. Emergency departments have contingency infection prevention plans to protect you from getting COVID-19 if you need care.
- Call your healthcare provider if you have any concerns about your underlying medical conditions or if you get sick and think that you may have COVID-19. If you need emergency help, call 911 right away.
- If you don’t have a healthcare provider, do a search at San Antonio Regional Hospital's Find a Physician or contact your local health department.
Information gathered from CDC website
About Us
Here For Life.
Our mission is to improve the health and wellbeing of the people we serve.