If you feel fatigue and weakness after taking herbal medicine, it may be caused by the wrong medicine or the medicine itself factors. It is necessary to give feedback to the herbalist who prescribed the medicine and consult whether it is necessary to change the medicine or stop using it. The possible reasons and related suggestions are as follows: 1. The medicine is not the right evidence: for example, a cold patient mistakenly uses a medicine to clear heat and generate sweat, which leads to excessive sweating, and the body’s vital energy comes out in large quantities with the loss of fluid, which may lead to a large deficiency of vital energy and fatigue and weakness. At this time, you can drink more light salt water to replenish water, and at the same time pay attention to keep warm to avoid aggravation of the disease; 2, drug effects: for example, the use of blood-stasis activating drugs, including salvia, myrrh, safflower, panax ginseng, possibly because of blood vessel unblocking, blood redistribution, blood pressure slightly reduced, at this time there may be dizziness, fatigue feeling. Bed rest is recommended for observation. Usually, a period of rest can relieve the discomfort. Fatigue is a non-specific symptom that can be caused by many conditions. If this symptom occurs, it is also necessary to exclude the possibility of other diseases. You need to contact your primary care physician and go to the hospital for a professional doctor to make a judgment. The doctor will treat the patient according to the cause of fatigue and weakness and provide targeted treatment to relieve the symptoms as soon as possible.