Runny nose in a child: how it runs and when an examination is needed

A runny nose is the most common symptom of childhood and almost always a sign of an ordinary viral infection. The lining of the nose swells, discharge increases, and breathing gets harder. For an older child it is mainly an inconvenience, but for a baby it is a real obstacle to feeding and sleep — which is exactly why the assessment depends on age.

How the discharge usually changes

A typical viral runny nose has a recognisable sequence. At first the discharge is thin and clear, and there is a lot of it. After a few days it becomes thick and cloudy and can take on a yellow or greenish tint. Then the amount decreases, and the runny nose gradually goes away.

Why green mucus does not mean a bacterial infection

This is probably the most persistent parental misconception, and it most often leads to an unnecessary antibiotic. The colour of the discharge cannot tell you whether this is a virus or a bacterium: thick greenish mucus occurs in an ordinary cold without any bacterial complication.

A doctor's decision about whether an antibiotic is needed for inflammation of the nose and sinuses rests on other things: the course of the illness over time, the child's general condition, the presence of marked local symptoms, and whether the condition worsened after a period of improvement. Modern guidelines are built exactly this way — prescribing an antibiotic is a separate clinical decision, not a reaction to a colour.

How long a runny nose lasts

Usually about a week to ten days, sometimes longer, and residual congestion can persist when the child already feels well. Children who attend a nursery or kindergarten often “layer” one infection onto another, and to the parent it looks as if the runny nose never stops for months — in reality it is several episodes in a row.

A runny nose that drags on continuously for many weeks, or comes with constant congestion, snoring, mouth breathing, or a worsening of the general condition, deserves a separate discussion with a doctor.

Nasal congestion: why it matters more in babies

Children in their first months breathe mainly through the nose and cannot “switch” to the mouth as easily as adults. A blocked nose stops them sucking: the child takes the breast or bottle, makes a few movements, pulls away to take a breath, gets tired, and eats less.

• Watch the feeding, not the amount of discharge: how much the child drinks, whether they pause, whether they tire.
• Assess urination — it shows whether the child is getting enough fluid.
• Look at the breathing at rest: calm or with effort.

A runny nose together with a fever and a cough

This combination is typical of a respiratory infection and does not in itself indicate a complication. What matters is the trend: if the temperature fell and then returned together with a worsening of wellbeing, the child needs to see a doctor. Fever and cough are covered separately in the links below.

When a lingering runny nose stops being just a runny nose

When congestion and discharge do not go away for a long time, the issue may be inflammation of the sinuses — sinusitis. That too is caused by viruses in most cases, and many such episodes end without an antibiotic. So the guide is not the colour of the discharge and not the mere fact of “a week of a runny nose already”, but other signs.

• marked pain — a headache or pain in the face;
• a worsening after the child had already started to feel better;
• no improvement for more than 10 days;
• a temperature lasting more than 3–4 days;
• episodes repeating several times within a year.

Any one of these is a reason to show the child to a doctor, not to start treatment on your own. With some cases of sinusitis the doctor deliberately chooses observation or a delayed prescription instead of an immediate antibiotic: this is not a refusal of treatment, but a way of not giving a medicine where it will not help.

What helps at home

• enough to drink — the mucus becomes less thick;
• cool, humidified air in the room;
• rinsing the nose with saline solution, especially before feeds in babies;
• a slightly raised head position during sleep for children who no longer sleep in a cot without a pillow;
• no tobacco smoke indoors.

This page is for general information only and is not a substitute for a consultation with a doctor. A child's diagnosis and treatment are determined by a doctor during an examination.