Cold vs flu vs RSV is the question in a lot of Austin homes right now. Someone has a cough, someone else has a fever, and nobody is sure what they caught.
The honest answer is that these viruses overlap a lot. Still, a few patterns can help you sort them out. This guide shows how to tell them apart, what is going around in Texas, and when to get care.
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What’s Going Around in Texas Right Now?
It is early in the season, and the numbers show it. The most recent Texas DSHS respiratory virus report we found covers the week of September 20 to 26, 2026:
- Flu: Activity was minimal, but hospital lab positivity rose to 3.65%, up from 2.16% the week before.
- RSV: Lab positivity was low, at 1.34%.
- COVID-19: Texas reported 1,880 new cases, down about 8% from the prior week.
Expect those numbers to change. The CDC says RSV spreads mainly in fall and winter and usually peaks in December and January. The Texas health department says flu season typically starts around October and peaks from December through February.
For the newest data, check the CDC respiratory illness activity map.
Quick Answer: Cold vs Flu vs RSV
A cold starts slowly with a stuffy nose, sneezing, and a sore throat, and it rarely brings a fever. Flu hits suddenly with fever, body aches, and tiredness. RSV looks like a cold in most people, but it can cause wheezing and trouble breathing in babies and older adults. Symptoms overlap, so only a test can tell for sure.
Cold vs Flu vs RSV Symptom Chart
Use this chart as a guide, not a diagnosis. It is based on CDC descriptions.
| Symptom | Cold | Flu | RSV |
|---|---|---|---|
| How it starts | Gradual | Sudden | Gradual, about 4 to 6 days after infection |
| Fever | Rare | Common, lasts about 3 to 4 days | Possible |
| Body aches and headache | Slight or rare | Common, often severe | Not a main symptom |
| Runny or stuffy nose, sneezing | Typical | Sometimes | Common |
| Cough | Mild to moderate | Can be severe | Common, may come with wheezing |
| Tiredness | Sometimes | Usual | Reduced activity in young infants |
| Highest risk | Few, mostly mild | Adults 65 and older, children under 5, pregnant women, people with chronic conditions | Infants under 6 months, older adults, people with certain risk factors |
Not everyone fits the chart. The CDC notes that not everyone with flu has a fever.
Why Symptoms Alone Are Not Enough
The CDC says RSV symptoms are hard to tell apart from those of a cold, the flu, or COVID-19. For flu and COVID-19, the CDC is blunt: you cannot tell the difference by symptoms alone.
A test is the only sure way to know. Our care team and onsite lab services can help you figure out which tests fit your symptoms. If COVID-19 is a worry, read about our rapid COVID-19 testing and treatment.
How to Tell a Cold From the Flu
These clues come from the CDC:
- Speed: Flu usually comes on suddenly. A cold builds slowly.
- Fever: Common with flu and lasts about 3 to 4 days. Rare with a cold.
- Aches: Often severe with flu. Slight with a cold.
- Tiredness: Usual with flu. Only sometimes with a cold.
- Nose and throat: A stuffy nose, sneezing, and sore throat point more toward a cold.
- Cough and chest: Can be severe with flu. Mild to moderate with a cold.
You can also catch flu more than once. Our post on getting the flu twice in one season explains why.
What Makes RSV Different
RSV is a common virus that usually causes mild, cold-like symptoms. The CDC lists a runny nose, congestion, cough, sneezing, fever, decreased appetite, and wheezing. They tend to appear gradually, about 4 to 6 days after infection.
In very young infants, RSV may show up mainly as irritability, less activity, and trouble breathing.
Most infections clear in about 1 to 2 weeks. The CDC says antivirals are not routinely recommended.
RSV can be serious, though. The CDC calls it the leading cause of infant hospitalization in the U.S. and the most common cause of bronchiolitis and pneumonia in children under 1. It can also make asthma or COPD worse in adults.
Who Is at Higher Risk?
For flu, the CDC lists these groups as higher risk of complications:
- Adults 65 and older
- Children younger than 5, especially those younger than 2
- Pregnant women
- People of any age with chronic conditions such as asthma, diabetes, or heart disease
For RSV, severe illness is most likely in:
- Infants younger than 6 months
- Older adults
- People with certain risk factors
If you care for a baby or an older relative, our guide on protecting seniors and infants during severe Austin weather swings has more tips.
Can You Treat a Cold, Flu, or RSV at Home?
Most healthy people recover at home. The CDC says most RSV infections clear on their own in about 1 to 2 weeks.
Rest, fluids, and close watching of symptoms are the basics. Ask your doctor or pharmacist before giving any medicine, especially to children.
Our guide on cold, flu, and RSV season in Austin has more on home care and when to come in.
Warning Signs: When to Get Emergency Care
Most cases are mild. Get care right away if you see these signs, which come from the CDC’s flu warning signs and RSV guidance.
Warning Signs in Adults
- Trouble breathing or shortness of breath
- Chest or belly pain or pressure that will not go away
- Confusion, dizziness that will not go away, or not being able to stay awake
- Seizures
- Not urinating
- Severe muscle pain or severe weakness
- Fever or cough that gets better, then returns or gets worse
- A chronic condition that gets worse
Warning Signs in Children and Babies
- Fast or hard breathing, or ribs pulling in with each breath
- Bluish lips or face
- Signs of dehydration, such as little or no urine, dry mouth, or no tears
- Not drinking enough fluids
- Not alert or not interacting when awake
- Fever above 104°F that medicine does not control
- Any fever in a baby younger than 12 weeks
- Seizures
Call 911 for severe trouble breathing or if someone is very hard to wake.
Our walk-in ER is open at any hour, and our children’s ER services page shows how we care for kids. Not sure where to go? Read ER vs urgent care in Austin.
How to Lower Your Risk This Season
Get Your Flu Shot
The CDC recommends a flu vaccine every season for nearly everyone 6 months and older. Texas health officials urge people to get one as soon as possible.
When the vaccine matches the circulating viruses, it cuts the risk of needing a doctor visit for flu by 40% to 60%, according to the CDC.
Ask About RSV Protection
The CDC recommends RSV vaccines for all adults 75 and older, and for adults 50 to 74 who are at increased risk.
Babies have two options for protection: an RSV vaccine given during pregnancy, or an RSV antibody given to the baby after birth. Ask your doctor what fits your family.
Keep Up Everyday Habits
- Wash your hands often
- Cover coughs and sneezes
- Stay home when you are sick
Cold vs Flu vs RSV: Frequently Asked Questions
What is the main difference between a cold and the flu?
Speed and severity. Flu comes on suddenly with fever, aches, and tiredness. A cold builds slowly and is usually milder.
Is RSV just a cold?
In most healthy people, RSV acts like a cold. It can be serious in babies, older adults, and people with certain risk factors.
Can I tell flu from COVID-19 by symptoms?
No. The CDC says symptoms alone cannot tell them apart. A test can.
How long does RSV last?
Symptoms usually appear 4 to 6 days after infection, and most infections clear in about 1 to 2 weeks.
When is flu season in Texas?
It typically starts around October, peaks from December through February, and can last as late as May.
Should I go to the ER for a fever?
It depends on who has it and what else is going on. Go right away for any fever in a baby younger than 12 weeks, a fever above 104°F that medicine does not control, or a fever with trouble breathing or confusion.
Not Sure What You Have? We Are Open 24/7
When you cannot tell cold vs flu vs RSV, trust how the person looks and acts. If breathing is hard or something feels wrong, do not wait.
Priority Emergency Center is open every hour of every day in Austin. You can find us on our location page or reach out through our contact page.
This article is for general education and is not a substitute for medical advice. In an emergency, call 911.
