Colds and flu – telling them apart, and what helps
A cold builds slowly and a flu arrives like a truck. Neither is helped by antibiotics. What actually shortens the misery, and the signs that need a clinic.
The difference is the onset
A cold comes on over a day or two: sore throat first, then a blocked or running nose, then a cough. You feel unwell but you get on with things. Influenza arrives abruptly — often people can name the hour — with fever, severe muscle aches, headache and exhaustion that puts you in bed.
The everyday use of 'flu' for any winter cold is why people underestimate the real thing. Actual influenza is a serious illness that kills South Africans every winter, mostly older adults, pregnant women and people with chronic conditions.
What actually helps
- Rest and fluids. Unglamorous, and the most effective things on the list.
- Paracetamol or an anti-inflammatory for fever, headache and aches.
- Salt water gargles for a sore throat, and steam or a hot shower for congestion.
- Honey for a cough in anyone over one year old — it has better evidence behind it than most cough syrups.
- A decongestant nasal spray for a few days only. Longer than that causes rebound congestion that is worse than the original.
For symptoms, not for the virus:
Paracetamol — Panado, Painamol, Tylenol, Pacimol
Mild to moderate pain; fever
Ibuprofen — Nurofen, Brufen, Advil, Ibupain
Mild to moderate pain; inflammation; fever; dysmenorrhoea
Oxymetazoline Nasal Spray — Drixine, Iliadin, Afrin, Otrivin Adult
Acute nasal congestion; sinusitis (short-term)
Sodium Chloride Nasal Spray/Rinse (Saline) — Salex, Flo Saline, Flo Sinus Care, Sterimar
Nasal congestion; daily nasal hygiene; post-nasal drip; sinusitis; dry nasal passages
Vitamin C does not prevent colds in most people and shortens them by a negligible amount. Combination flu remedies are convenient but frequently double up on paracetamol you are already taking — read the ingredients.
When it is not just a cold
In South Africa, a cough lasting more than two weeks — especially with night sweats, weight loss or fever — needs a TB test, free at any clinic. That is the single most important thing to rule out and the one most often left too long.
Not passing it on
- Wash hands properly and often — these viruses spread on hands and surfaces at least as much as through the air.
- Cough into your elbow, not your hand.
- Stay home while feverish, particularly away from older relatives and anyone with a chronic condition.
- The flu vaccine, in early autumn, for anyone in a higher-risk group.
Common questions
- Why will the doctor not give me antibiotics?
- Because colds and influenza are viral, and antibiotics only work on bacteria. Prescribing them anyway gives you the side effects with none of the benefit and makes bacteria in your body harder to treat later.
- Does green mucus mean I need antibiotics?
- No. Colour comes from immune cells doing their job and changes over the course of an ordinary viral cold. It is not a reliable sign of bacterial infection.
- How long should a cold last?
- Most settle within a week to ten days, though a cough can linger for two to three weeks afterwards. A cough beyond two weeks should be assessed rather than waited out, particularly here.
Sources
- Primary Healthcare Standard Treatment Guidelines and Essential Medicines ListNational Department of Health, South Africa
- Communicable disease surveillance and clinical guidanceNational Institute for Communicable Diseases, South Africa
Last reviewed 4 August 2026.