Here an acute onset of the disorder appears after exposure to cold, rain or snow, or consumption of a large amount of cold drink and food. Patients may suffer from cramping pain in the limbs, abdominal pain, diarrhea, cold extremities or dysmenorrhea. There is a pallid complexion, a white tongue coating and a wiry and deep pulse.

This syndrome can be found in elderly people and in people with a poor constitution or with chronic disease. They may suffer from cold extremities, cold in the back and cold knees, frequent urination, impotence, infertility, dysmenorrhea, aqueous-grainy diarrhea and edema. A light purple tongue body with a white and moist coating and a deep, slow and weak pulse are found in most cases. These symptoms can be seen in chronic nephritis, pyelitis and hypofunction of the pituitary gland, the adrenal cortex or the thyroid gland.

This syndrome is often seen in people with chronic digestive disorders. They suffer from abdominal pain of a cramping nature, diarrhea or soft stools without a strong smell, edema, distension of the abdomen and a poor appetite, and have a preference for warm drinks rather than cold. A pale tongue body with a thick white coating and a weak and slow pulse are often seen. This pattern can be found in chronic colitis, peptic ulcer, chronic enteritis, liver disease, hypothyroidism and chronic nephritis.

This syndrome exists in people who are under stress or emotional distress for a long period of time. The symptoms and signs are palpitations, shortness of breath, chest pain and an oppressive sensation, cold limbs, depression, a bluish tongue body with purple spots, and a deep, wiry and irregular pulse.

Collapse of Yang is caused by serious disturbance of the balance between Yin, Yang, Qi and Blood under the influence of pathogenic factors. When the Blood and Yin are suddenly weakened, or the Qi and Blood are suddenly obstructed, they fail to support the Yang, so the Yang collapses. This syndrome can be seen in critical conditions, especially after the collapse of Qi, such as seen in shock caused by myocardial infarction, myocarditis, severe blood loss, trauma, severe dehydration or allergy. The main symptoms are extremely cold extremities, a cold sensation that cannot be alleviated by warmth, a pallid complexion, an apathetic expression, slow reactions, shallow breathing and profuse sweating. The tongue body is pale and the pulse is thready, weak and deep.

Both exogenous pathogenic Cold and internal Cold from Yang deficiency of the internal organs can exist in this pattern. The main symptoms are cold and severe pain in the limbs, cramp in the muscles, stiffness of the body, dysmenorrhea and cramping pain in the sides of the lower abdomen. These symptoms worsen with cold. The tongue body is bluish, its coating is white and the pulse is wiry, deep and slow.

When Cold obstructs the movement of the Qi and circulation of the Blood, it can directly cause pain which is characterized by sudden onset, cramp and a preference for warmth, such as seen in Cold Painful Obstruction syndrome, dysmenorrhea and muscle strain.

Most of the herbs that warm the Interior are very pungent and hot. Pungency can disperse Cold, open up the meridians, and promote Qi movement and the Blood circulation. Heat can directly reduce Cold, warm the Interior and relieve cramp caused by Cold.

The Heart-Yang, Spleen-Yang and Kidney-Yang are very important for maintaining the function of other internal organs. They stimulate Qi movement and the Blood circulation, and can promote digestion and water metabolism. Some herbs mainly warm the Yang of one of these three organs. The herbs that are used to warm the Heart-Yang are Gui Zhi ( Cinnamomi cassiae ramulus) and Rou Gui ( Cinnamomi cassiae cortex). The herbs that are often used to warm the Spleen-Yang are Gan Jiang ( Zingiberis rhizoma), Gao Liang Jiang ( Alpiniae officinari rhizoma), Wu Zhu Yu ( Evodiae fructus), Hua Jiao ( Zanthoxyli fructus) and Xiao Hui Xiang ( Foeniculi fructus). The herbs that are used for warming the Kidney-Yang are Fu Zi ( Aconiti radix lateralis preparata)* and Rou Gui.

Some herbs are very pungent and hot, their speed of scattering Cold and spreading warmth is very high, and they are considered to enter the 12 regular meridians; an example is Fu Zi.

The herbs that can expel exogenous pathogenic Cold from the superficial region of the body were detailed in the chapters on herbs that release the Exterior (Ch. 2) and herbs that expel Wind-Dampness (Ch. 5). Some of these can also be used for treating Interior Cold syndromes.

In clinical practice, herbs that warm the Interior and expel Cold should be used with caution. First, these herbs are very pungent and hot, and they can consume the Yin and Body Fluids. If used for too long or in too large a dosage, they may bring about side-effects such as dryness in the mouth, throat and nasal cavity, thirst, sore throat, constipation, itching and dry skin, a burning sensation in the Stomach and palpitations. Patients with Yin and Blood deficiency should not use them. Secondly, many patients with Blood deficiency often show symptoms of internal Cold. In this condition, herbs that warm the Interior should not be used in large amounts. Thirdly, these herbs are pungent and harsh, and are able to stimulate the Blood circulation, so should not be used in bleeding conditions or in pregnancy. However, if the bleeding causes the collapse of Yin, and further collapse of the Yang, herbs that tonify the Qi and herbs that rescue the Yang can be used together. Fourthly, in the condition of Yang collapse, herbs that rescue the Yang should be applied in time. If the Yang is extremely weak and the internal Cold exceeds its maximum, and there is a fierce conflict between the Cold pathogenic factor and the hot herbs, a small amount of cold herbs, which serves as an ‘opposing assistant’, should be added in with the larger amount of hot herbs in order to achieve the proper therapeutic result.

Herbs that stimulate the Yang are also called ‘herbs that warm the Interior’ or ‘herbs that expel internal Cold’. They are pungent and hot, and can directly scatter internal Cold. They are used for treating Excessive internal Cold syndromes. They can also stimulate the Yang of the internal organs, and accelerate their functions so as to disperse the internal Cold in both Excess and Deficiency conditions. The commonly used herbs are Fu Zi ( Aconiti radix lateralis preparata)*, Gan Jiang ( Zingiberis rhizoma) and Wu Zhu Yu ( Evodiae fructus). In clinical practice, the therapeutic effect of these herbs is rapid, and results in raising of the blood pressure, body temperature and heart rate, and a reduction in the reaction time of the patient. These herbs are particularly used in critical conditions, such as shock or heart or renal failure.

As these herbs are very pungent and hot, however, they can easily consume Yin and Body Fluids, so should not be used for a long period of time. In the treatment of chronic internal Cold syndromes caused by Yang deficiency, the effect of these herbs in warming the Yang and expelling Cold is neither reliable nor stable. If these herbs are used for a longer period of time, they may also consume the Yin, further damage the Yang and complicate the patient’s condition.

Herbs that tonify the Yang are sweet and slightly warm. They can tonify the weakness of the Yang of the internal organs by replenishing the shortage of Essence. They can warm the Yang and promote its function gently. They are particularly used for treating Deficiency of the Yang in chronic diseases, especially deficiency of the Kidney-Yang. They improve the condition of patients slowly but steadily. The commonly used herbs are Du Zhong ( Eucomniae cortex), Gou Ji ( Cibotii rhizoma)**, Yi Zhi Ren ( Alpiniae oxyphyllae fructus) and Tu Si Zi ( Cuscutae semen).

In many books, herbs that stimulate the Yang and those that tonify the Yang are often called ‘herbs that warm the Yang’ or ‘herbs that strengthen the Yang’. This leads to confusion. However, there are some herbs that are pungent, hot and sweet, and have functions both of stimulating the Yang and of tonifying the Yang. These include Rou Gui ( Cinnamomi cassiae cortex), Ba Ji Tian ( Morindae radix), Yin Yang Huo ( Epimedii herba) and Gui Zhi ( Cinnamomi cassiae ramulus). They can be used in both Excess and Deficiency conditions.

In clinical practice, herbs that stimulate the Yang and herbs that tonify the Yang can be used together to treat the syndrome of Yang deficiency with internal Cold.