Cold vs. Flu: What's the Difference?
Medically reviewed by [Clinician name, credentials] on [date]
Colds and the flu are both caused by viruses, and both can make you feel miserable. But the flu is usually worse and more likely to cause serious problems. Knowing the difference helps you decide whether to rest at home or call a clinician quickly.
This page is for general education. It isn't a diagnosis and doesn't replace a visit with a clinician.
What are colds and the flu?
A cold is a viral infection of the nose and throat. The CDC says more than 200 respiratory viruses can cause colds, and colds usually last less than a week. Adults get an average of two to three a year.
The flu (influenza) is a contagious illness caused by influenza viruses. The CDC says it can cause mild to severe illness, and at times can lead to death. Most people recover in a few days to less than two weeks. Some develop complications like pneumonia.
COVID-19 and RSV can also cause cold-like symptoms. If you think you might have flu or COVID-19, especially if you're at higher risk, get tested.
Common symptoms
Here's how they usually compare, based on CDC information:
| Symptom | Cold | Flu |
|---|---|---|
| How it starts | Gradually | Suddenly |
| Fever | Rare | Common; lasts 3–4 days |
| Body aches | Slight | Common; often severe |
| Chills | Uncommon | Fairly common |
| Tiredness, weakness | Sometimes | Usual |
| Sneezing | Common | Sometimes |
| Chest discomfort, cough | Mild to moderate | Common; can be severe |
| Stuffy nose | Common | Sometimes |
| Sore throat | Common | Sometimes |
| Headache | Rare | Common |
Not everyone with the flu has a fever. Some people, more often children, have vomiting and diarrhea.
Who is at higher risk from the flu?
The CDC says these groups are more likely to have serious flu problems:
- Adults 65 and older
- People with chronic conditions like asthma, diabetes, or heart disease
- Pregnant people
- Children under 5, especially under 2
When telehealth works — and when you need in-person care
Telehealth often works well for:
- Sorting out whether it's more likely a cold, flu, or something else
- Deciding if you should take a flu antiviral medicine
- Advice on rest, fluids, and over-the-counter medicines that are safe with your other conditions
- Checking in if you're not getting better
You may need in-person care for:
- A flu or COVID-19 test, if your clinician wants one [CONFIRM: testing options, e.g., home tests or local lab]
- Trouble breathing, chest pain, or other warning signs (see below)
- A cough or fever that improves and then comes back worse
How Oceanside Health can help
- Quick video visits when you first get sick. [CONFIRM: same-day availability]
- Flu antiviral medicine when it makes sense. The CDC says these prescription medicines work best when started within 1 to 2 days after symptoms begin. They can shorten illness by about a day and help lower the risk of some complications. The CDC recommends prompt treatment for people at higher risk. Most healthy people with mild illness don't need them.
- No unneeded antibiotics. Antibiotics don't treat colds or flu, and they can cause side effects.
- Follow-up if you're not improving.
- Prevention. The CDC recommends a flu vaccine every year for everyone 6 months and older. [CONFIRM: whether Oceanside offers vaccines or refers to pharmacies]
We see patients by video across Brevard County, including Titusville, Cocoa, and Rockledge.
Call 911 or go to the ER if…
The CDC lists these emergency warning signs in adults. Get medical care right away for:
- Trouble breathing or shortness of breath
- Pain or pressure in the chest or belly that won't go away
- Dizziness that won't go away, confusion, or being hard to wake
- Seizures
- Not peeing
- Severe muscle pain
- Severe weakness or unsteadiness
- Fever or cough that gets better, then comes back or gets worse
- Chronic health problems getting worse
In children, the CDC also lists fast or hard breathing, bluish lips or face, ribs pulling in with each breath, chest pain, seizures, severe muscle pain (refusing to walk), signs of dehydration (no pee for 8 hours, dry mouth, no tears when crying), not being alert, a fever above 104 °F that medicine doesn't bring down, and any fever in a baby younger than 12 weeks.
Frequently asked questions
How long am I sick with a cold or flu?
Colds usually last less than a week and peak in 2 to 3 days. Most people with the flu recover in a few days to less than two weeks.
Can antibiotics help a cold or the flu?
No. Both are caused by viruses. Antibiotics don't work against viruses and can cause side effects.
Should I take a flu antiviral?
It depends. They're most helpful when started within 1 to 2 days of symptoms, and the CDC especially recommends them for people at higher risk. Your clinician can help you decide.
Can a cold turn into something worse?
Sometimes. The CDC lists ear infections and sinus infections as possible complications. More serious ones include asthma attacks, bronchitis, and pneumonia. Call your clinician if you're getting worse instead of better.
Can I give my child cold medicine?
The CDC says not to use over-the-counter cough and cold medicines in children younger than 4 unless a clinician tells you to. Never give aspirin to children, because it can cause Reye's syndrome. Ask about the right dose for your child's age and size.
Book a visit
Just started feeling sick? Timing matters with the flu. Book a visit or call 321-878-8195. Please don't send health details through this website or by email. We'll go over everything privately during your visit.
If you think you're having an emergency, call 911.
Sources
- CDC. Signs and Symptoms of Flu. https://www.cdc.gov/flu/signs-symptoms/index.html
- CDC. Treating Flu with Antiviral Drugs. https://www.cdc.gov/flu/treatment/antiviral-drugs.html
- CDC. About Common Cold. https://www.cdc.gov/common-cold/about/index.html
- CDC. Sinus Infection Basics (over-the-counter medicine and children). https://www.cdc.gov/sinus-infection/about/index.html
Medically reviewed by [Clinician name, credentials] on [date]. Next review due: [date + 12 months].