How long does a cold last, and why the cough outlasts everything else

How long does a cold last? The NHS says you should begin to feel better in about 1 to 2 weeks. Most of the pages you find when you search for it are American and say 7 to 10 days. Both leave out the part that sends people to the GP: the cough lasts longest, about 18 days on average in adults.

How long does a cold last, according to the studies

The reference figure comes from the review by Heikkinen and Järvinen in The Lancet: the mean duration of the common cold is 7 to 10 days, but in a proportion of patients some symptoms can still be present after 3 weeks. The NHS puts it in plainer words: symptoms come on gradually over 2 to 3 days, and you should begin to feel better in about 1 to 2 weeks.

Symptoms build quickly, peak after 2 or 3 days and then ease slowly, each at its own pace:

Children take a little longer. A systematic review by Thompson and colleagues in the BMJ, drawing on 48 studies, found that about half of children had improved by day 10 and nine in ten had recovered by day 15, which the authors called "considerably longer" than the guidance given to parents in the UK and the US.

Why the cough lasts longer than the cold

Once the runny nose and sore throat have gone, the airways are still irritated and the cough stays, often dry. The NHS draws its line for the cough at 3 weeks, not 10 days. Feeling run down for a while is common too, and on its own it says little: low ferritin, for instance, is found with a blood test, not by how tired you feel.

Before you read the figure, make your guess:

That gap is the most useful thing on this page. Ebell and colleagues asked 493 adults how long they thought an acute cough lasts: 5 to 7 days was the median answer. In the published studies, the mean was 17.8 days. The authors link that mismatch to people asking for antibiotics that do not help.

What the top ten search results say

On 23 September 2026 we read the ten pages that rank highest in the UK for "how long does a cold last", word for word.

Six of the nine pages with text say "7 to 10 days", and the UK answer is not the same: 1 to 2 weeks. Neither is wrong, because one describes when you start to feel better and the other the average length of the illness. But if you read the American figure on day 11, you will think something is off, and by the NHS's measure it is not. It is not the only health question where UK readers get an answer written for the United States: the same happens with high uric acid, reported in µmol/L here and in mg/dL there.

When to see a GP about a cold

The length of a cold on its own is rarely the reason. What matters is getting worse instead of better and a few warning signs. Each country sets the bar in a different place, and none sets it at one week:

For children, the NHS adds one more: see a GP if you are worried about your child's cold symptoms. You do not need to wait for any particular day. As for the temperature on that list, the NHS counts 38C or above as high, and a normal body temperature is lower than the 37C most of us learnt.

Cold or flu: how to tell the difference

Not by how long they last. According to the NHS, the difference is in how they start and how unwell you feel:

How long is a cold contagious

From a few days before symptoms begin until they have finished, according to the NHS. The peak is in the first 2 or 3 days: with rhinovirus, the amount of virus shed peaks on the second day and falls quickly after that.

And one correction worth making every winter: getting cold does not cause a cold. The review in The Lancet says the evidence, although scarce, does not support the popular belief that chilling causes colds.

What shortens a cold, and what does not

The evidence here is short and fairly clear. Test yourself first:

What the NHS recommends is easing the symptoms while the cold runs its course: rest, plenty of fluids, a hot lemon and honey drink or salt-water gargles for the throat, and paracetamol or ibuprofen if you need them. It also says GPs do not recommend antibiotics for colds, because they will not relieve your symptoms or speed up your recovery. Zinc is the one with some evidence, and low certainty; we set the Cochrane review next to the foods that are highest in zinc.

Our view

What we would do. Count from the first day and watch the direction, not the calendar, the same rule we apply to DOMS. If each day is a little better than the last, a cough in the third week is within what is expected. If a day is worse, or a high temperature appears, that is when we would book an appointment, whatever the date.

What we disagree with. Answering this question with "7 to 10 days" and nothing else. It is half the answer, and the missing half, the cough, is exactly what sends people to the surgery for no reason.

What we do not know. There is no curve for adults as good as the children's one in the BMJ: the 17.8 days for cough mixes colds with acute bronchitis. Nor can we say why the UK, Spain and France set the point to seek help at such different places: 10 days, 10 days and 15 to 20.