More than half of people who recover from COVID-19 report fatigue 10 weeks later after Covid-19, regardless of the seriousness of their initial infection. It is a long-term illness that affects many body systems. It is especially important for people at increased risk of severe illness from COVID-19 to protect themselves getting COVID-19 and treat it in time after the patients have post-Covid 19 fatigue. TCM has been used for treating post-Covid 19 fatigue and receiving successful results in the world.
In TCM, the post-Covid 19 fatigue might be referred to Lassitude（倦怠Juan Dai）, deficient syndrome(虚损Xu Sun) . 薛生白《湿热病篇》:暑月病初起， 但恶寒， 面黄， 口不渴，神倦四肢懒，脉沉弱，腹痛下利，湿困太阴之阳，宜仿缩脾饮，甚则大顺散，来复丹等法。Dr Xue Shengbai in his book, the Damp warm febrile disease says: the illness just occurs during the summer, as long as there are chills, yellow face, not thirsty, fatigue and extremities lassitude, deep and weak pulse, painful abdomen and loose feces, which is due to dampness accumulating the Yang of Taiyin. The Suo Pi Yin, Da Sun San and Lai Fu Dan are useful. Dr Xue discussed the fatigue and lassitude during damp warm febrile diseases and his therapy for the fatigue.

What is the etiology, pathogenesis and therapy?

With the dampness lingering the all processes of Covid 19, it consumes spleen Yang or damages Yin of lung, stomach, heart or liver and kidney. The location focuses on the spleen and effects other Zang Fu organs. There is deficiency during the post-Covid 19, such as Qi, blood, Yin and Yang deficiency of Zang Fu organs, also could be excessive, such as Qi stagnation and damp phlegm accumulation.

Both liver and kidney Yin deficiency:

Senile patient with the Yin deficient constitution post Covid-19, the pathogens trendily turns to heat and it leads to the Yin of liver and kidney is further damaged. The Yin deficiency of liver and kidney fails to nourish the bones and tendons manifested as low back and knees pain, hot flash and night sweating.

Manifestations: Tired, low back and knees pain, hot flash and night sweating, thirsty, constipation, less or irregular period, premature ejaculation, tinnitus, dizziness, red tongue with less or peeled coating, deep, weak and rapid pulse.

Treatment Strategy: Nourish the Yin of the liver and kidney.

Formula: Liu Wei Di Huang Wan.
The Qi Ju Di Huang Wan can be used if the patients have severe tinnitus and dizziness. Zhi Bai Di Huang Wan can be used as the patients have more hot flash, night sweating, burning sensation of urine.

Acupuncture points: UB18, UB23, Ki3, Liv3, GB20.

Both lung and heart Qi, Yin deficiency:

The damp toxin of Covid-19 damages the Qi and Yin of heart. The Qi of lung fails to take charge of Qi manifested tired, shortness of breath and weak voice. The lung and heart Yin is injured fails to be nourished manifested as dry cough, dry mouth, palpitation and mental depression.

Manifestations: tired, shortness of breath, weak voice, dry cough, dry mouth, palpitation and mental depression, small and pale tongue without coating, deep weak and rapid pulse.

Treatment Strategy: Tonify the Qi and nourish the Yin of the lung and heart.

Formula: Sheng Mai San modified.
If there is anxious, palpitation and insomnia, Dan Shen, Huang Qi can be added in the formula. If there is obvious chronic cough, Bu Fei Tang can be added.

Acupuncture points: Lu1, PC6, Ki6, St36, Ren17.

Both heart and spleen deficiency:

The spleen is accumulated by the dampness during Damp Warm febrile disease, or injured by the over used the cold bitter herbs, and medicines, all of them result in spleen, and the spleen fails to generate the Qi and blood to nourish the heart, therefore, the patients have the manifestations of both heart and spleen deficiency.

Manifestations: Fatigue, lassitude, insomnia, palpitations, poor appetite, pale complexion, pale lips and tongue and deep weak pulse.

Treatment Strategy: Tonify the Qi and blood of heart and spleen.

Formula: Gui Pi Tang.
If there is severe poor sleep and dreams, the Suan Zao Ren, Ye Jiao Teng are added.

Acupuncture Points: Ren14, Ren12, Sp6, Ht7, Anmian.

Middle Qi deficiency:

Dampness lingers inside, lost chance treated in time or incorrect therapy, resulting in spleen Qi deficiency, and the spleen fails to generate Qi to nourish the muscles of extremity, manifested as lassitude, weakness of muscles. When the clear Qi fails to ascend to nourish brain, the patients will have fatigue, dizziness, loose feces.

Manifestations: Fatigue, lassitude, dizziness, poor appetite, loose feces, pale tongue with thin white coating, deep and weak pulse.

Treatment Strategy: Tonify the middle Qi.

Formula: Liu Jun Zi Tang.
Liu Jun Zi Tang is mostly used for fatigue, lassitude, poor appetite, loose bowl movement due to the Qi deficiency of spleen and stomach. It also can be used for Lung and spleen Qi deficiency with dampness and phlegm manifested as fatigue, chronic cough with phlegm and pale tongue with white greasy coating. The Bu Zhong Yi Qi Tang is used for if fatigue and dizziness are due to prolapsed middle Qi.
Acupuncture Points: Du20, Ren12, St36, Sp6, SP4.

Spleen Yang deficiency with dampness:

The dampness of Covid-19 injures Yang of spleen, which usually occurs in patients with underlining Yang deficiency, or over used the bitter herbs, medicines inappropriately. The Yang fails to warm the exterior with intolerance of cold. Spleen, even kidney Yang deficiency results in overflow of water and dampness with lassitude, fatigue, puffy face,

Manifestations: Fatigue, heavy sensation of the body, puffy face, diarrhea and edema of limbs, bloating abdomen, pale and swollen tongue with white and greasy coating, deep and weak pulse.

Treatment Strategy: Warm the spleen Yang and eliminate dampness.

Formula: Fu Zi Li Zhong Tang.
For significant edema due to Yang deficiency of Spleen and Kidney, use Zhen Wu Tang.

Acupuncture points: Ren12, Ren6(Moxa), St36, Du4(Moxa), SJ5, Sp9.

Liver Qi stagnation with spleen Qi deficiency:

With the stress before suffering Covid-19, or suffering stress post it, it results in liver Qi stagnation manifested as depression, fullness of hyperchondric. The pathogens damage spleen Qi manifested as fatigue, poor appetite.

Manifestations: Fatigue, hyperchondric pain, bloating abdomen, poor appetite, loose feces, pale tongue with thin white coating, wiry pulse at left, deep and weak pulse at right.
Treatment Strategy: sooth liver Qi and strength spleen Qi.

Formula: Xiao Yao San.
For significant liver Qi stagnation, add Xiang Fu, Zhi Shi. For severe fatigue with Qi deficiency, add Huang Qi, and Ren Shen. For depression and poor sleep, add He Huan Pi and Ye Jiao Teng.
Acupuncture Points: Yintang, Liv13, LI4, Liv3, Ren12.

Other therapies:

Cupping: Moving Cupping along Huatuo Jiaji and the back Shu of UB.

Guasha: Push Guasha along the Du, Ren, and UB channel.

Xie Wei Tie Fu: Use Ren Shen, Shan Zhu Yu, Fu Zi and Rou Gui(1:1:1:1), 0.5g put on each point at five back Shu, Du4, and Ren3. It is used for fatigue due to five Zang Organs deficiency.