Viral infections of the nose and throat, spread easily through coughs, sneezes and contaminated surfaces.
Colds and flu are both viral infections of the respiratory tract, but flu tends to come on faster and hit harder — with higher fever, more pronounced body aches and greater fatigue than a typical cold. Both are extremely common and, for most healthy people, resolve without specific treatment within one to two weeks.
Colds are caused by a wide variety of viruses, most commonly rhinoviruses, while flu is caused specifically by influenza viruses that circulate seasonally and change slightly from year to year. Both spread through respiratory droplets and contaminated surfaces, and crowded indoor settings during cooler months see the highest transmission.
Most cases are managed with rest, fluids, and symptom relief while the immune system does the work of clearing the virus. Flu in particular can sometimes benefit from antiviral treatment if started early, and anyone in a higher-risk group — young children, older adults, or those with underlying conditions — should be assessed sooner rather than later if symptoms are significant.
Seek care if: a fever persists beyond a few days, or breathing becomes difficult — this can point to a more serious infection needing assessment.
