Tonic substances are divided into four categories:

- Qi tonics that are sweet and warm, strengthen vital activity, especially spleen and lung functions. Qi is responsible for the generation and circulation of blood. Its lack presents loss of appetite, soft stools, feeling of heaviness and distension, discouragement, lassitude, edema and rectal prolapse. Indicated in cases of spleen Qi deficiency and liver Qi deficiency;

- Yang tonics are warm and warm and particularly tonify the yang of the kidneys and are indicated for insufficiency of the yang of the kidneys which presents aversion to cold, cold limbs, inflammation and pain in the lower back and knees, increased nocturia, impotence and premature ejaculation or dyspnea ,  and deficiency of the yang of the kidneys and spleen with diarrhea.

- Blood tonics are mostly sweet and warm. Indicated to treat heart and liver blood deficiency, with pale complexion, pale lips and nails, dizziness, blurred vision, palpitations, insomnia and irregular menstruation. can too  nourish the yin.

- Yin Tonics are sweet and cool, nourish the yin fluid, promote the production of fluids and relieve dryness. They are classified in tonics of:

    - Yin of the lungs: dry cough, hemoptysis and dry throat;

    - Stomach yin: thirst, gastric changes, acid regurgitation and belching;

    - Yin of the liver: dizziness and xerophthalmia;

    - Kidney yin: low back pain, premature ejaculation, evening fever, night sweats, and heat in the hands and soles of the feet.

​

   Qi, Blood, Yin and Yang are interdependent and affect each other. In the disability of:

- Qi and Yang indicate hypofunction of vital activity;

- Yin and blood indicate consumption of essence, blood and bodily fluids.

​

   Tonic substances are not indicated for syndromes with excessive pathogenic factor, especially when the antipathogenic factor is not weakened, inappropriate use in these circumstances can promote perverse Qi and aggravate the disease.