Syndrome differentiation plays a major role in TCM diagnosis, and the premise is to identify a syndrome according to four paired principles:

• Location of disease between the exterior and interior body;
• Nature of disease between cold and heat;
• Individual constitutions that lean towards a deficiency or excess;
• Finally, generalizing the syndrome as yin or yang.

During the consultation process, physicians will analyse the location, cause, mechanism and nature of the disease. They try to define a syndrome pattern for the signs and symptoms that manifest at a given stage of the disease, and then give the diagnosis a TCM term that illustrates the involved parts of the body and relevant pathological conditions. This diagnostic term will guide the physician to formulate therapeutic strategies using herbs, needles, diet or other traditional techniques. In female infertility, there are six typical syndrome patterns: 1. Kidney-yang deficiency The main manifestations are infrequent menstruation, delayed menstruation or menopause. Menses are generally light colored, thin and scanty. Individuals usually have watery or excessive white-turbid vaginal discharge. Other associated symptoms are soreness in the lumbar (lower back) and knee regions, fatigue, general weakness, puffiness, aversion to coldness, limb coldness, a cold feeling in the lower abdomen, low libido, profuse and clear urine, nocturnal urination, loose bowels, black eyes, a dull complexion and darkish spots on the face. On examination, the tongue is pale and tender covered by a white and moist fur. The pulse is deep and slow or deep, thready and weak.   2. Kidney-yin deficiency Individuals present with frequent or infrequent menstruation; the menses are bright red but scanty. Other associated symptoms are being thin in appearance, annoying hot sensations in the chest, palms and soles, soreness in the lumbar and knee regions, insomnia, night sweats, ear ringing and a dry mouth. On examination, the tongue is red and tender with a little or no fur covering. The pulse is thready and weak or a little bit rapid.   3. Blood and Qi weakness The main manifestations are excessive or scanty menses, which are light-colored and thin. Individuals are usually delayed in menstruation and may have a dull pain in the lower abdomen after each cycle. Other associated symptoms are dizziness, palpitations, dull or sallow complexion, fatigue, limb numbness and insomnia. On examination, the tongue is pale with thin and white fur; the pulse is thready and weak or deep and thready.   4. Qi and blood stagnation The main manifestations are irregular menstruation and dysmenorrhea (painful menses). The menses are purplish dark with plenty of blood clots. There may also be infrequent menstruation. Other associated symptoms are scaly skin, purplish lips, brownish spots or pigmentation on the face, distending pain in the breasts and lower abdomen. Individuals usually suffer from uterine myoma (muscular tumor), ovarian cysts or masses in the pelvic region. On examination, the tongue is darkish red. Bleeding spots may be found in the margin. The pulse is deep and taut.   5. Liver-qi stagnation The main manifestations are irregular cycles with impeded menstrual flow. The color is darkish red with small pieces of blood clots. There is distending pain in the breasts and abdomen before the menstruation cycle begins. Other associated symptoms are an uneasy mind, irritability, depression, sighing, or feeling sad without reason in severe cases. On examination, the tongue is darkish red with a thin and white fur. The pulse is deep and thready.   6. Interior struck by phlegm and dampness The main manifestations are menopause or a delay in cycles, impeded menstrual flow and scanty menses. Individuals usually have excessive thick vaginal discharge. Other associated symptoms are being overweight, chest oppression, retching, poor appetite, loose bowels, a bright pale complexion, fatigue, excessive sweating, dizziness and heart palpitations. On examination, the tongue is pale, bulky and tender and may have indentation markings around the margin from the teeth. White and greasy fur may cover it. The pulse is deep, slow and rolling.   It should be emphasized that infertility usually results from multiple factors; thus, individuals may present a complex syndrome in reality. An experienced physician is necessary for an accurate diagnosis. The table below provides a general reference about the Western classifications of infertility and the possible dominant TCM syndrome patterns.

Western Diagnoses	TCM Syndrome Patterns
Ovulation problems	Kidney deficiency & excessive phlegm Deficiency in kidney yin and kidney yang Deficiency in kidney yin and liver yin Virtual Heat due to yin deficiency Kidney deficiency and blood stasis
Uterine problems	Blood stasis Blood stasis & qi stagnation Blood stasis & qi stagnation
Tubal problems	Blood stasis & qi stagnation Damp-heat in lower burner
Immune problems	Not specified, may show virtual heat due to yin deficiency sometimes.