If your baby is younger than 4 months and they are coughing you should be concerned and if the coughing lasts longer than a few hours in babies younger than 4 months you should take the baby to the doctor.
Other reasons you should be concerned about your baby's cough are.
A dry cough related to a cold (a runny nose but no fever) that lasts more than five to seven days.
A dry or wet cough with a cold and a fever of 100 degrees or more. Mild, light wheezing
It is normal for babies to cough sometimes but sometimes the coughing can be a cause for concern or mean the baby has some other illness.
Not all cases of coughing in babies or toddlers is a bad thing but they can sometimes be.
In some ways, coughing is actually a good thing because it's a reflex that helps protect baby's throat and chest airways.
But it's also a signal of an irritation in baby's air passages: the lungs or throat.
If the cough lasts for more than three to four weeks, it's considered chronic and isn't typically normal for infants.
Babies can also cough when they are teething.
The extra saliva produced during teething can cause an occasional cough or gag.
How to help your infant's coughing: If your infant's cough continues or is accompanied by a high fever and cold or flu symptoms, contact your infant's pediatrician.
Babies cough and sneeze for the same reasons we do: to clear their nasal passages of something irritating, such as dust, or to move mucus or saliva out of their throats.
"Coughing and sneezing are the only ways babies have of clearing their airways—of lint, spit-up etc.
A cough that has persisted for a week or more without any other signs of illness (like runny nose, fever, or lethargy) or allergies (clear discharge) could mean that your child has something stuck in his throat or lungs.
A variety of viral respiratory infections can lead to coughing due to irritation and inflammation in the airways.
Some infections that are usually caused by viruses and can lead to a dry cough in kids include: common cold. influenza.