Syndrome differentiation and treatment
The therapeutic principle of asthma lies in eliminating pathogenic factors to treat secondary symptoms at the stage of attack. The therapeutic methods include warming the lung to eliminate sputum and asthma, clearing away heat from the lung, eliminating phlegm and asthma according to the state of pathogenic cold or heat. At the remission stage, the therapeutic methods include removing the latent sputum inside the body by strengthening the lung, spleen and kidney to prevent asthma.

1. Cold asthma 
Main symptoms and signs: Cough with wheezing, throat rale, profuse-thin-whitish-frothy sputum, cold  body, anhirosis, cold lower limbs or thin nasal discharge, dim and sluggish complexion, reddish tongue with thin whitish or whitish-greasy tongue coating, floating and  slippery pulse. 
Therapeutic methods: Warming the lung, resolving sputum and eliminating asthma.

2. Heat asthma
Main symptoms and signs: Asthmatic cough with sputum and rale, yellowish and thick sputum, sonorous voice with short breath, chest distress and fullness, dysphoria, thirst, or fever, constipation, yellowish urine, reddish tongue with thin and yellowish or yellowish and greasy fur, slippery and rapid pulse.
Therapeutic methods: Clearing away heat from the lung, resolving sputum and soothing asthma.

3.  Lung qi deficiency  
Main symptoms and signs: Remission of the onset, pale complexion, low spirit, short breath, weakness, spontaneous sweating, aversion to cold, repeated attack by cold, pale tongue with thin and whitish fur, thready and forceless pulse.
Therapeutic methods: Tonifying the lung, supplementing qi and strengthening the exterior.

4. Deficiency of spleen qi 
Main symptoms and signs: Profuse sputum, epigastric fullness, sallow complexion, poor digestion, loose bowels, lassitude, weakness, reddish tongue with a little fur, slow and weak pulse. 
Therapeutic methods: Replenishing the spleen, supplementing qi and resolving sptum.

5. Deficiency of kidney qi 
Main symptoms and signs: Susceptibility to short breath, cold body with aversion to cold, cold limbs, enuresis or profuse nocturia, pale and tender tongue with whitish fur, deep and thready pulse.
Therapeutic methods: Strengthening the kidney, reinforcing primordial qi and consolidating the congenital foundation.