This principle of tonification is an important one in Chinese medicine, as it can be applied to deal with inherent deficiency and acquired deficiency alike, so long as there are signs of yin or yang deficiency, energy deficiency, blood deficiency, shortage of semen, or shortage of fluids and so on.

There are four methods of tonification:
To tone up energy deficiency,
To tone up blood deficiency,
To tone up yin deficiency and
To tone up yang deficiency.

1. To tone up energy deficiency
This involves treating the energy deficiency syndrome, the lungs energy deficiency syndrome and the spleen energy deficiency syndrome.

These syndromes may give rise to the following symptoms: fatigue, weakness, shortness of breath, too tired to talk, feeble and low voice, Asthma triggered by labor or movements, whitish complexion, poor appetite, watery stools, excessive perspiration, Edema, weak pulse, prolapse of the anus and prolapse of the uterus.

2. To tone up blood deficiency
This is used to treat the blood deficiency syndrome, with the following symptoms: pale or withering and yellowish complexion, pale lips and nails, dizziness and spots in front of the eyes, palpitations, Insomnia, irregular menstrual periods, scant menstrual flow in light color, numbness of hands and feet, pale tongue and fine pulse.

3. To tone up yin deficiency
This is used to treat the yin deficiency syndrome, with the following symptoms: loss of weight, dry mouth and throat, dizziness, ringing in the ears, sore loins and weak legs, red tongue with scant coating and fine pulse.

The same treatment principle is also effective for the deficiency fire syndrome, with the following symptoms: red lips, reddish appearance in the zygoma, feeling depressed, insomnia, hot sensations in the middle of the palms and the soles of the feet, periodic fever, night sweats, Seminal Emission and discharge of blood from the mouth.

4. To tone up yang deficiency
This is used to treat the yang deficiency syndrome, with the following symptoms: fear of cold, cold limbs, sore loins, weak legs, cold pain across the loins or in the legs, Impotence, sliding ejaculation, a long stream of plentiful clear urine, pale tongue and deep, fine and weak pulse.

All of these symptoms are mostly seen in the kidneys yang deficiency syndrome. The heart yang deficiency syndrome and the spleen yang deficiency syndrome should be treated by the principle of warming up.