WHEN YOUR CHILD HAS A LONG-LASTING COUGH, WHEN SHOULD YOU SEE A DOCTOR?

This article is written by Dr. Đặng Ngọc Vân Anh, Specialist Level I – Pediatrics, at CarePlus International Clinic System.

Coughing is a natural and beneficial reflex that helps clear the airways, remove dust and phlegm, and make it easier for children to breathe. However, if the cough persists continuously—especially when it makes the child tired, disrupts sleep, causes vomiting, or leads to breathing difficulties—parents should not ignore it. So, how long should a child cough before seeing a doctor? What causes persistent coughing in children?

All of these will be explained by the doctor in the following article to help parents better understand and know when to take their child for timely medical care.

1. When is a cough considered prolonged in children?

A child is considered to have a prolonged cough if it lasts for more than 4 consecutive weeks (according to guidelines from respiratory specialists in the U.S., Australia–New Zealand, and Europe).

Usually, coughs caused by a common cold or mild respiratory infections resolve within 4 weeks. But if the cough persists beyond this period, parents should pay attention, as it may indicate an underlying condition that affects the child’s health, sleep, and daily activities.

2. Causes of prolonged cough in children

There are many causes of persistent dry cough in children. Conditions such as bronchitis, ear infections, sinusitis, and gastroesophageal reflux can all contribute.

Classified by duration of cough:

• Acute cough (<2 weeks): Often caused by acute respiratory infections, asthma, or inhalation of foreign objects.

• Subacute cough (2–4 weeks): Often follows viral infections, bacterial infections, whooping cough, or prolonged/recurrent respiratory infections, including tuberculosis.

• Chronic cough (>4 weeks): Can result from post-viral or bacterial infections, whooping cough, prolonged/recurrent respiratory infections, tuberculosis, asthma, gastroesophageal reflux, postnasal drip, or congenital and chronic cardiopulmonary conditions.

Classified by age group:

Infants (<1 year old):

• Congenital abnormalities in the airways

• Tracheoesophageal fistula or neurological disorders affecting the cough reflex

• Viral or bacterial infections (whooping cough, pneumonia, flu, etc.)

Preschool children (1–5 years old):

• Inhalation of foreign objects (food, small toys)

• Viral or bacterial respiratory infections

• Allergic reactions, asthma, or cystic fibrosis

• Exposure to tobacco smoke, cooking smoke, or airway irritants

School-age children and adolescents:

• Asthma, postnasal drip, or recurrent respiratory infections

• Exposure to tobacco smoke, air pollution, or dusty environments

• Psychological factors such as stress or anxiety may also contribute to prolonged coughing

3. Evaluating a child with a prolonged cough

Evaluating a child with a prolonged cough requires a systematic approach, including a detailed medical history, clinical examination, and sometimes chest X-rays or lung function tests.

Medical history: Focus on symptoms and risk factors:

• Cough characteristics: chronic cough with phlegm or dry, wheezing, or difficulty breathing

• Triggers: cough after choking, physical exertion, weather changes, or feeding

• Underlying conditions: heart problems, neurological disorders, immune deficiencies, or other suspected illnesses

• Timing of worsening cough: at night/early morning (suggestive of asthma), after lying down (postnasal drip, reflux), or mainly in the morning

• Birth and family history: allergies, asthma, tuberculosis

• Environmental factors: exposure to dust, smoke, pets

• Medications used previously

Clinical examination: The doctor will conduct a thorough assessment to identify the cause:

• General appearance: weight, height, nutrition, development, and congenital abnormalities

• Skin: eczema, rashes, or signs of viral infection

• Ears: check for abnormal eardrum, ear discharge, or foreign objects (rare cause of chronic cough via ear reflex)

• Nose: swelling, polyps, or allergic rhinitis

• Throat: hoarseness, enlarged tonsils, or congenital anomalies

• Heart: abnormal location or murmurs

• Chest and cough: observe cough type and sound; if the child is not coughing, the doctor may ask them to cough or rely on recordings from parents

These observations help the doctor determine the cause and select the appropriate diagnostic and treatment methods.

4. When additional tests are needed

If the cough persists, the doctor may order tests to identify the cause, including:

• Blood tests: check white blood cells and signs of infection or inflammation

• Chest X-ray: examine lungs and airways

• Lung function tests: for children over 6 if asthma is suspected

• ENT endoscopy: detect problems in the nasal and throat area; respiratory endoscopy if airway foreign body is suspected

• CT scan: if congenital airway abnormalities are suspected

• Abdominal ultrasound: if gastroesophageal reflux is suspected

• Allergy tests: identify airway irritants

• Tuberculosis tests: if risk factors are present

The goal of these tests is to accurately identify the cause, allowing effective treatment and faster recovery for the child.

"Pay attention to your child’s symptoms and monitor their cough—don’t hesitate to bring them to CarePlus Pediatrics, where experienced doctors provide thorough examinations, recommend the right tests, limit unnecessary antibiotics, and offer proper care advice, helping your child recover quickly, develop fully, and giving parents peace of mind."