No, studies have shown that milk does not cause phlegm or increase mucous production in throat or airways. However, you may feel that your saliva is thicker from the temporary mixing of milk and saliva.
Don’t avoid dairy. It’s an important source of calcium and protein! Aim to reach your daily dairy serves today :)
Source:
Wüthrich B, Schmid A, Walther B, Sieber R. Milk Consumption Does Not Lead to Mucus Production or Occurrence of Asthma. Journal of the American College of Nutrition. 2005;24(sup6):547S-55S.
Pinnock CB, Graham NM, Mylvaganam A, Douglas RM. Relationship between Milk Intake and Mucus Production in Adult Volunteers Challenged with Rhinovirus-2. American Review of Respiratory Disease. 1990;141(2):352-6.