Late menstruation according to Chinese Medicine

Blood Deficiency leads to an insufficient amount of Blood in the Directing (Ren Mai 任脉) and Penetrating (Chong Mai 冲脉) Vessels. As they're the Vessels directing and coordinating Blood to the Uterus, the sheer lack of Blood means the periods will fail to happen at the expected time and get delayed consistently.

There can be several underlying reasons for this pattern but chronic illnesses or excessive work are typically the major ones because they impair the Spleen's transforming function. The Spleen is the base of creating Gu Qi (or called Food Qi) and Food Essence which are essential for the creation of Blood. Also, long-term chronic excessive bleeding such as menorrhagia may also cause Blood Deficiency. Finally, breastfeeding for a long time may leads to this pattern as well because breast milk is also made from Blood and may therefore exhaust its supply. 

The treatment principle is to nourish Blood and Qi. Formulas such as Ren Shen Yang Rong Tang are recommended to supply both Blood and Qi. Da Bu Yuan Jian is to tonify Qi and Yang and nourishes Blood, Essence and Yin. Therefore it is for the most severe cases of the condition. 

Read more about Blood Deficiency here

Blood can congeal due to Cold invasion. Then new Blood can not be created and the Directing (Ren Mai 任脉) and Penetrating (Chong Mai 冲脉) Vessels are empty. They fail to fill the Uterus and thus the periods consistently come after the expected time. Other typical symptoms are a feeling of cold, scanty periods with dark blood and clots and abdominal pain which can be relieved with Heat. There are two types of Cold in the Uterus pattern that can cause delayed menstruation: Full or Empty. 

For the Full type, it often happens to women living in cold and damp countries or to women who spend large amount of time outdoor in cold weather. Young girls during their puberty are particularly vulnerable as their bodies are easily affected by external pathogenic factors such as 'cold evil'. Another source of Full Cold in the Uterus is diet. Excessive consumption of raw or cold foods can accumulate Cold in the body. The treatment principle is to warm the Uterus, disperse Cold and regulate the periods. Formulas like Wen Jin Tang are recommended. 

As for Empty Cold in Uterus, the 'Empty' here refers to the fact that the 'Cold' is caused by a lack of Yang which by nature is a warm substance. Apart from the typical symptoms mentioned above, patients may also feel tired under this Empty pattern. The treatment principle should rather focus on tonifying Yang instead of just warming the Uterus and dispersing Cold. Formulas such as Da Ying Jian are recommended. 

Read more about Cold in the Uterus here

Whenever the body has Dampness or Phlegm, the Spleen is always the first Organ that should be checked since it controls body water metabolism. The Spleen transforms, transports, and distributes Body Fluids along with food Essence and Grain Qi. If its transforming ability is poor, the Body Fluids can congeal to create Phlegm and cause Edema. As a vicious cycle, Phlegm can further impair the Spleen's transforming function. Therefore, not enough new Blood can be created to overflow the Uterus and periods become consistently late. Phlegm can also block Qi movement and cause Qi or Blood Stagnation. 

The treatment principle is to strengthen the Spleen and disperse phlegm. In case there is also Blood Stagnation, invigorating the Blood should also be considered. 

Read more about Damp-Phlegm in the Uterus here

Qi Stagnation here mainly refers to Liver Qi Stagnation which is often caused by long-term emotional stress like worry or fear. If untreated for a long period of time, it can lead to Blood Stagnation and thus the Directing (Ren Mai  任脉) and Penetrating Vessels become blocked and periods come behind schedule. 

Heart or Spleen Qi Deficiency can also be caused by these emotions and be responsible for delayed periods. Take the Spleen as example, its function is to transform and transport food and drinks, extracting Grain Qi (Gu Qi) and food Essence out of them, and distributing them to other Organs. It is the foundation of Blood making. In case of Spleen Qi Deficiency, the transforming function will not work properly and thus not enough Blood can be produced to send to the Uterus. It can lead to either scanty periods or late periods. 

The treatment principle is to pacify the Liver, move Qi, eliminate Stagnation, invigorate Blood and therefore regulate the periods. Of course it goes without saying that treatment can only work long term if the patient deals with their emotional stress as well, if it continues the patterns will keep from coming back again and again.

Read more about Qi Stagnation here

Kidney Yang is considered the 'primary Yang'. It is the root of Yang for all other Organs and all the Yang energies of the entire body. In the case of Kidney Yang Deficiency, this results in a situation where there is not be enough Kidney Essence to create Blood, nor sufficient Qi to move Blood to the Lower Burner. Then the Directing (Ren Mai 任脉) and Penetrating (Chong Mai 冲脉) Vessels are not nourished and the Sea of Blood fails to fill the Uterus, hence the delayed periods. Long-term Kidney Yang Deficiency can also cause Empty Cold in the Uterus pattern. 

Many reasons can lead to this pattern, such as hereditary Kidney weakness, chronic disease, overwork, excessive sex, recreational drugs, poor sleep, aging or giving birth to too many children too close together. The treatment principle is to tonify Yang, strengthen the Kidneys and warm the Uterus. A typical herbal formula is Shen Qi Wan. 

Read more about Kidney Yang Deficiency here