It’s not true that you can’t drink milk with a cough, it should be case by case.
Cough can drink milk in most cases, such as cough caused by the common cold, pneumonia, tuberculosis, cough caused by gastroesophageal reflux, etc., is generally not a contraindication to drink milk. Moreover, drinking milk appropriately can help enhance one’s own resistance, which may be helpful for the recovery of the condition.
However, some cough patients can not drink milk, such as cough variant asthma, some patients may be allergic to milk, for the above special people, if you drink milk may lead to allergies, but also because of allergies and trigger the aggravation of cough symptoms.
To sum up, whether patients with cough can drink milk, need to be analyzed in conjunction with their own situation.