Flu or cold: symptoms, progression, and duration

“Oh, I don't feel well” – if this is the first thought you have in the morning, there is a good chance that you have caught a cold or even the flu. While colds can be caused by over 200 different viruses, only influenza viruses – more specifically, virus types A and B – are responsible for the flu. Nevertheless, they have one major thing in common: they affect our respiratory tract. And that's exactly why they can be easily confused. But how can you tell the difference between the flu and a cold?

Flu vs. cold: a comparison of the most important symptoms

Similar, but with subtle differences: cough, sore throat, runny nose – even though many symptoms of the flu and a cold are very similar, they often vary in intensity. The symptoms of the flu are usually so severe that all you want to do is stay in bed. Aches and pains and headaches do the rest. High fever is also one of the typical symptoms of the flu. A cold, on the other hand, is usually milder: muscle and joint pain, but also fever, are rare. 

From the first sneeze to the last cough: the progression of flu and colds

The differences between flu and colds become clearer when you take a closer look at their progression: flu usually starts very suddenly—from one moment to the next, you feel weak, feverish, and completely knocked out. With an incubation period (the time from infection to the first signs of illness) of only one to two days, it shows what it has to offer right from the start. It often begins immediately with aching limbs, fever, and a sore throat. A dry cough also sets in early with the flu and can be particularly persistent. It often lasts for days without the formation of mucus and develops into a stubborn cough as the illness progresses. While the acute symptoms of the flu usually subside after five to seven days, the general feeling of illness can persist for longer.

A cold, on the other hand, creeps up slowly—the incubation period is around two to seven days. Usually, you first get a sore throat, followed by a stuffy or runny nose and general malaise. The cough usually develops after a few days: initially it is dry and irritating, later it becomes more productive and accompanied by mucus formation. The airways, irritated by the inflammation, can then cause a persistent dry cough that persists beyond the acute phase of the illness. However, the symptoms usually improve within a few days, so that a cold can disappear after just a week. A herbal cough remedy such as Prospan can help to alleviate the symptoms of coughing and shorten the duration of the illness: the special ivy extract contained in Prospan acts as an expectorant and can also help to relieve the urge to cough.

Flu and colds: How long am I contagious?

Whether it's the flu or a cold, when you've caught it, there's one thing you definitely don't want to do: infect others. With both respiratory diseases, you can actually be infectious one to two days before the first symptoms appear. The contagious period then lasts about a week, but this can vary from person to person and therefore from immune system to immune system. As a rule of thumb, anyone with acute symptoms is contagious.