In some people-children as well as adults- a simple nose cold easily ends up with a bronchitis or even more serious.[DESCENDING cold: which from experience of the patient often goes over in a dry cough or bronchitis]
The patient or the parents tell that is nearly routinely happening with colds.
To prevent this I have found a herb very effective, again and again.
Sticta pulmonaria: which I give in a low potency homeopathic, dilution D3.
You can ask for drops or globules and take 2 times a day a globule or a few drops with the very beginning of a cold.
As always let me know your experience.