Cold vs Influenza (Flu): A Clear, Workplace-Friendly Guide for Australia

Both the common cold and influenza are viral respiratory infections, but they behave differently. Colds tend to start gradually with a runny/blocked nose, sneezing, sore throat and a mild cough. Flu often hits suddenly with fever greater than 38 °C, chills, muscle aches, headache and profound fatigue that can put people in bed. Antibiotics don’t help colds or flu; antivirals may help influenza when started within 48 hours in higher-risk adults. Hand hygiene helps both; annual influenza vaccination remains the most effective flu prevention for eligible adults in Australia (IDSA/Clin Infect Dis 2019, AFP 2019, Ann Intern Med 2021).

By Aitor Aspiazu, Founder & Managing Director / Lead Nurse Consultant (RN), Corporate Care.

“In a busy workplace, the question isn’t just cold vs flu—it’s how we reduce spread and downtime. Clear comms, easy access to vaccination, and simple sickness policies make the biggest difference.” — Aitor Aspiazu, RN.

Organise Flu Vaccination for your employees today, and boost the health and well-being of your organisation.

What is the Difference Between a Cold and Influenza (The Flu)?

How They Start?

• Common cold — usually gradual onset: runny/blocked nose, sneezing, sore throat, mild cough; fever (if present) is typically low-grade. People often keep working, just slower (Lancet Infect Dis 2005; AFP 2019; CHEST 2017).
• Influenza — often sudden onset: fever greater than 38 °C, chills, aching muscles, headache, dry cough, marked fatigue; many feel too unwell for normal activities. Sore throat/runny nose can occur, but are less prominent than with a cold (IDSA/Clin Infect Dis 2019; Lancet Infect Dis 2005; BMJ Open 2025; AFP 2019).

How Long They Last?

• Cold: typically 5–10 days; cough/tiredness can linger up to two weeks (AFP 2019; CHEST 2017).
• Flu: most recover in about a week; cough/fatigue may persist longer—especially in older adults (CDC Yellow Book).

How Serious Are They?

• Cold: generally mild; complications are rare.
• Flu: can be serious, especially for young children, older adults, pregnant people, and those with chronic conditions; complications include pneumonia and exacerbations of existing illness (AFP 2019; CDC Yellow Book; Ann Intern Med 2021).

Cold vs Flu Symptoms (At-A-Glance)

Sources: IDSA/Clin Infect Dis 2019, Lancet Infect Dis 2005, BMJ Open 2025, ACP/Ann Intern Med 2016, AFP 2019 – Colds, CHEST 2017, AFP 2019 – Influenza, CDC Yellow Book.

Googling “flu vs cold symptoms” or “head cold vs flu”? Use fever + sudden whole-body aches as your first clues for influenza. Only testing confirms (BMJ Open 2025).

Age Groups in Australia: Who’s Most Affected?

• Influenza: the heaviest burden (hospitalisations and mortality) is in the very young (<6–12 months) and older adults (?75 years), with clear excess respiratory mortality/hospitalisation in these groups (Int J Epidemiol 2022; PLOS One 2020).
• Paediatric Severity: children <16 years also experience substantial burden, including ICU admissions—many previously healthy (PLOS One 2016).
• Pandemic Dynamics: school-aged children and young adults can show higher infection rates than older adults during pandemics (Med J Aust 2006).
• Common Cold: very frequent in children and declines with age; usually mild with rare hospitalisation (Epidemiol Infect 2014; PLOS One 2014; AJRCCM 2021).

Why this matters at work: even when illness is mild, clusters create absenteeism. Clear “stay home when unwell” guidance and easy access to influenza vaccination reduce spread and downtime.

Treatment: What Actually Helps

• Common Cold: rest, fluids, simple pain relief/decongestants as needed. Antibiotics don’t help viral upper respiratory infections and are not recommended for uncomplicated colds (ACP/Ann Intern Med 2016; AFP 2019 – Colds; CHEST 2017).
• Influenza: rest and fluids for most adults. For higher-risk adults or severe disease, clinicians may prescribe antivirals if started within 48 hours to shorten illness and reduce complications (IDSA/Clin Infect Dis 2019; AFP 2019 – Influenza).
• Red Flags (seek urgent care): breathing difficulty, chest pain, severe headache, confusion, dehydration, or symptoms that worsen or last >2 weeks.

Prevention That Works

• Hygiene: handwashing/sanitiser, cover coughs/sneezes, clean shared surfaces, and stay home when unwell (AFP 2019 – Colds).
• Annual Influenza Vaccination: recommended in Australia for people ?6 months of age, especially those at higher risk (AFP 2019 – Influenza; Ann Intern Med 2021).
• For formulation context (including the 2026 Southern Hemisphere update), see Corporate Care’s explainer: https://corporatecare.com.au/flu-vaccination/flu-vaccine/

Cold or Flu?”—A 30-Second Self-Check (Not A Diagnosis)

• Sudden fever >38 °C with chills + muscle aches? More likely to be influenza than a head cold.
• Mainly nose/throat symptoms with little/no fever? More likely a common cold.
• High-risk or getting worse? Speak to your GP—early antivirals can help confirmed/suspected flu (IDSA/Clin Infect Dis 2019; AFP 2019).

For Employers: Simple Steps That Cut Absenteeism

1. Keep It Simple: “If you’re sick, stay home.” Provide easy access to RATs/masks for higher-risk settings.
2. Communicate Clearly: short messages on the difference between cold and flu, how to book vaccines, and when to seek help.
3. Make Vaccination Easy: on-site clinics or voucher pathways for hybrid teams; schedule before local transmission rises.
4. Track and Learn: monitor uptake and sickness patterns to optimise timing next season.

“We see the best results when companies make healthy choices the easy choices—clear comms, simple booking, and leadership modelling ‘stay home if you’re sick’.” — Aitor Aspiazu, RN.

Need help organising flu vaccines for your employees? Contact us today.

References (Outbound, Peer-Reviewed and Guideline Sources)

1. IDSA influenza guideline (2018 update) — Clin Infect Dis 2019. Uyeki TM, Bernstein HH, Bradley JS, et al.
   https://pmc.ncbi.nlm.nih.gov/articles/PMC6653685/
2. Common cold vs influenza symptoms — Lancet Infect Dis 2005. Eccles R.
   https://pubmed.ncbi.nlm.nih.gov/16253889/
3. Symptom accuracy for influenza (meta-analysis) — BMJ Open 2025. Ebell MH, Rahmatullah I, Hulme C, et al.
   https://pubmed.ncbi.nlm.nih.gov/40032401/
4. Antibiotic stewardship for URTI — Ann Intern Med 2016. Harris AM, Hicks LA, Qaseem A.
   https://www.acpjournals.org/doi/full/10.7326/M15-1840
5. Treatment of the common cold — Am Fam Physician 2019. DeGeorge KC, Ring DJ, Dalrymple SN.
   https://pubmed.ncbi.nlm.nih.gov/31478634/
6. CHEST expert panel: acute cough in the common cold — CHEST 2017. Malesker MA, Callahan-Lyon P, Ireland B, Irwin RS.
   https://pmc.ncbi.nlm.nih.gov/articles/PMC6026258/
7. Influenza: diagnosis & treatment — Am Fam Physician 2019. Gaitonde DY, Moore FC, Morgan MK.
   https://pubmed.ncbi.nlm.nih.gov/31845781/
8. CDC Yellow Book — Influenza
   https://www.cdc.gov/yellow-book/index.html
9. Influenza review — Ann Intern Med 2021. Uyeki TM.
   https://pubmed.ncbi.nlm.nih.gov/34748378/
10. Excess respiratory mortality & hospitalisations, Australia — Int J Epidemiol 2022. Leung VKY, Wong JY, Barnes R, et al.
    https://pubmed.ncbi.nlm.nih.gov/34333637/
11. Estimated influenza hospitalisations, Australia — PLOS One 2020. Moa AM, Muscatello DJ, Turner RM, MacIntyre CR.
    https://pubmed.ncbi.nlm.nih.gov/32282849/
12. Paediatric ICU admissions (influenza), Australia — PLOS One 2016. Kaczmarek MC, Ware RS, Coulthard MG, McEniery J, Lambert SB.
    https://pubmed.ncbi.nlm.nih.gov/27023740/
13. Pandemic influenza clinical issues — Med J Aust 2006. Boyd M, Clezy K, Lindley R, Pearce R.
    https://pubmed.ncbi.nlm.nih.gov/17115951/
14. Incidence of acute respiratory infections, Australia — Epidemiol Infect 2014. Chen Y, Kirk MD.
    https://pubmed.ncbi.nlm.nih.gov/24103382/
15. Risk factors for ARI, Australia — PLOS One 2014. Chen Y, Williams E, Kirk M.
    https://pubmed.ncbi.nlm.nih.gov/25032810/
16. Rhinovirus C immunity & age patterns — Am J Respir Crit Care Med 2021. Choi T, Devries M, Bacharier LB, et al.
    https://pubmed.ncbi.nlm.nih.gov/33357024/
17. Vaccine coverage/effectiveness in children — Clin Infect Dis 2019. Blyth CC, Macartney KK, McRae J, et al.
    https://pubmed.ncbi.nlm.nih.gov/30137244/

About the Author

Aitor Aspiazu, RN — Founder & Managing Director / Lead Nurse Consultant at Corporate Care. Aitor has 20+ years’ nursing experience (including emergency) and leads Corporate Care’s clinician-written protocols and workplace health education.

General information only. Not a substitute for personal medical advice. If you’re worried about symptoms, speak with your GP or local health service.