Phlegm syndrome refers to syndrome due to local retention of phlegm or migration of phlegm. Phlegm is produced by such factors like six exogenous pathogenic factors, emotional impairment, and improper food, overstrain and lack of necessary physical activities which affect the transforming functions of the lung, spleen and kidney, leading to stoppage of fluid distribution and production of phlegm. The retention of phlegm in viscera, meridians and tissues results in phlegm syndrome.
 
Clinical manifestations:
Cough with sticky sputum, chest oppression, or dizziness, or epigastric mass, anorexia, nausea, vomiting, or coma with sputum rale, or mental derangement with mania, dementia and epilepsy, or numbness of limbs, hemiplegia, or scrofula, goiter, breast nodules, phlegm nodules, greasy fur and slippery pulse.

Analysis of symptoms:
Phlegm is marked by variability in causing disease. So there is a saying that "all diseases are caused by phlegm". Chest oppression and cough with sticky sputum are due to retention of phlegm in the lung which affects the lung to disperse and descend; dizziness is due to phlegm invading the head and preventing lucid yang from rising; epigastric mass, anorexia, vomiting and nausea are due to retention of phlegm in the middle energizer that prevents the spleen from transforming and the stomach from descending; coma with sputum rale or mental derangement with mania, dementia and epilepsy are due to phlegm confusing the mind; numbness of limbs, or hemiplegia is due to retention of phlegm in the meridians and inhibited flow of qi and blood; scrofula, goiter, breast nodules and phlegm nodules are due to retention of phlegm in the skin and muscles; greasy fur and slippery pulse are signs of internal exuberance of phlegmatic dampness.
 
Key points for syndrome differentiation:
This syndrome is marked by vomiting of sputum or dizziness, vomiting, or coma with sputum rale, or numbness of limbs, or phlegm nodules, greasy fur and slippery pulse. Phlegm syndrome may be divided into cold phlegm, heat syndrome, damp phlegm, dry phlegm and stagnant phlegm according to the nature of phlegm and the complication which should be carefully differentiated.