Syndrome differentiation and treatment
Clinically, the commonly-seen syndromes include yin deficiency of the lung and kidney, qi deficiency of the lung and spleen as well as blood stasis and phlegm coagulation due to qi stagnation. These syndromes should be mainly treated with the methods of nourishing the lung and kidney and relieving sore throat to promote phonation, tonifying the lung and spleen and relieving sore throat to promote phonation, or promoting qi flow to activate blood circulation and resolving phlegm to promote phonation respectively.

1.  Syndrome of yin deficiency of the lung and kidney
Main symptoms and signs: The patient has prolonged hoarseness without cure and cannot speak persistently. Hoarseness will worsen after the patient is tired or speaks long. The larynx is slightly painful, uncomfortable, dry and itching. The patient suffers from cough and scanty sputum which is not easily expectorated and often clears his throat habitually by uttering "keng" and "ka". Examination may show slightly red swelling of the vocal fold with the marginal pachynsis. Or the patient has zygomatic flush and red lips, asthenic restlessness with less sleep, aching flaccidity of the waist and knees, feverish sensation of palms and soles, red tongue with scanty fur, thready and rapid pulse.
Therapeutic methods: Nourishing the lung and kidney, relieving the larynx to promote phonation.

2. Syndrome of qi deficiency of the lung and spleen
Main symptoms and signs: Hoarseness is prolonged and worsens after tiredness with the marked manifestation in the morning. The patient speaks in a low voice with strain for a short time. Examination shows pale laryngeal mucosa, relaxation and asthenia of the vocal fold with poor closure. The general symptoms include short breath,disinclination to speak, lassitude, hypodynamia, anorexia and loose stool. The tongue is pale and enlarged with white fur. The pulse is thready and weak.
Therapeutic methods:  Tonifying the lung and spleen, relieving sore larynx to promote phonation.

3. Syndrome of blood stasis and phlegm coagulation due to qi stagnation
Main symptoms and signs: The patient has prolonged hoarseness and speaks with strain. The intralaryngeal part is uncomfortable with foreign object sensation. The patient often clears his throat by uttering "keng" and"ka" habitually. Examination shows hypertrophy of the vocal fold and ventricular bands, or vocal nodules and polyp of the vocal fold. There often exists attachment of sticky sputum on the vocal fold. The general symptoms are not obvious or include thoracic tightness, cough and expectoration. The tongue is dark red with whitish thin fur and the pulse is unsmooth.
Therapeutic methods: Promoting qi to activate blood circulation, resolving phlegm to promote phonation.