Late Periods

Late periods, also known as postmenstrual bleeding, are defined as menstrual cycles that are consistently longer than 28-30 days (or at least for 3 consecutive months). The cycle can be up to 40-50 days long. Occasionally late periods can be caused by external circumstances such as emotional distress or traveling. If a period is suddenly late after being regular, it may indicate pregnancy.


  1. Chronic illness, excessive physical work, chronic bleeding, or excessive breastfeeding: A long-term illness, excessive physical work, or chronic bleeding can weaken the Spleen and lead to Qi and Blood deficiency. Excessive breastfeeding for a long time (e.g. 2 years) can also lead to Blood deficiency because breast milk and Blood come from the same source. In any of these cases, when Blood is deficient, the Directing and Penetrating Vessels are also devoid of Blood, leading to consistently late periods.

  2. Irregular diet, exposure to cold and dampness, or invasion of cold: Consuming too much raw, cold food over a long period of time can lead to internal Cold and potentially Yang deficiency. Exposure to cold and damp weather or living in a damp environment can also cause internal Cold and Dampness. In any case, Cold can invade the Blood portion and cause it to congeal, leading to empty Directing and Penetrating Vessels, an empty Sea of Blood, and late periods. This is a common cause of late periods (and also painful periods) in girls who play sports in cold and damp conditions. Cold and dampness are particularly harmful to young girls around puberty because their bodies are vulnerable and easily affected by any cause of disease.

  3. Hereditary Kidney weakness, overwork, or too many children too close together: All of the above causes can lead to Kidney weakness, causing the Kidneys to fail to nourish the Directing and Penetrating Vessels, leading to a lack of transformation of Kidney-Essence into Blood and an empty Sea of Blood, resulting in late periods.

  4. Emotional stress: Long-term emotional stress can lead to Liver-Qi stagnation, which can eventually cause Blood stasis and obstructed Directing and Penetrating Vessels, leading to late periods.


The main pathological factors in late periods are:

  • Blood deficiency
  • Cold in the Uterus (which may be Full- or Empty-type)
  • Kidney-Yang deficiency
  • Qi stagnation

The pattern of Kidney-Yang deficiency is more common in older women, while the other patterns can occur at any age. Invasion of Cold and Dampness is likely the most common cause of late periods in young women or girls. As they grow and develop, this can be complicated by other causes of disease such as overwork or emotional stress.


 Please note that the herbal formulas mentioned in this discussion are intended as a holistic support supplement and not a cure. They should be used in conjunction with a healthcare provider's advice and guidance. It is important to consult a qualified healthcare provider before taking any herbal formulas.

Treatment for late periods depends on the underlying cause. For example, treatment for Blood deficiency may involve nourishing Blood and regulating the periods. Herbal treatment may include the prescription Ren Shen Yang Rong Tang. Treatment for Cold in the Uterus may involve warming the Uterus and resolving Cold, with herbal treatment including the prescription Wu Zhu Yu Tang. Treatment for Kidney-Yang deficiency may involve nourishing Kidney-Yang and resolving Dampness, with herbal treatment including the prescription Jin Gui Shen Qi Wan and Er Chen Tang. Treatment for Qi stagnation may involve resolving stagnation and promoting Qi movement, with herbal treatment including the prescription Xiao Yao San.