What causes fatigue after surgery?
Oct 29, 2025
Source: Cainiu Health
Dr. Wang Lei
Introduction
Excessive energy consumption after surgery: The body consumes a large amount of energy during the surgical procedure, and continued energy is required for tissue repair afterward, leading to an energy-deficient state that causes fatigue, often accompanied by lethargy and reduced exercise tolerance. It is recommended that patients ensure adequate rest after surgery, minimize physical exertion, and gradually increase intake of easily digestible carbohydrates such as rice porridge and soft noodles to replenish energy.
Postoperative fatigue may result from excessive energy consumption, inadequate nutritional intake, improper postoperative care, hypokalemia, or postoperative anemia. If fatigue persists for more than one week or is accompanied by symptoms such as fever or palpitations, prompt medical attention is necessary.
1. Excessive Energy Consumption: Significant energy is expended during surgery, and continued energy is required for tissue repair afterward, leaving the body in a state of energy deficit that leads to fatigue. This is often accompanied by lethargy and reduced exercise tolerance. It is recommended to ensure adequate rest after surgery, minimize physical exertion, and gradually increase intake of easily digestible carbohydrates such as rice porridge and soft noodles to replenish energy.
2. Inadequate Nutritional Intake: Gastrointestinal function may not have fully recovered after surgery, or patients may eat less due to pain or poor appetite, leading to deficiencies in protein, vitamins, and other nutrients. This impairs bodily recovery and worsens fatigue, possibly accompanied by weight loss and delayed wound healing. It is advised to eat small, frequent meals and choose high-protein, high-vitamin foods such as steamed egg custard and vegetable puree. Nutritional supplements may be used under medical guidance if necessary.
3. Improper Postoperative Care: Poor postoperative care can lead to bacterial infection of the surgical wound or internal organs. The body's immune response to fight pathogens consumes substantial energy, resulting in fatigue along with fever, redness, swelling, pain at the wound site, or abnormal discharge. Follow your doctor’s instructions to use medications such as cefixime dispersible tablets, levofloxacin injection, or amoxicillin-clavulanate potassium tablets to alleviate symptoms.
4. Hypokalemia: Prolonged fasting, vomiting, or use of diuretics after surgery can cause excessive loss of potassium ions, impairing muscle contraction and causing fatigue. Symptoms may include limb weakness, bloating, and arrhythmias. It is recommended to take medications such as potassium chloride sustained-release tablets, potassium magnesium aspartate tablets, or potassium chloride injection under medical supervision to relieve discomfort.
5. Postoperative Anemia: Significant blood loss during surgery or insufficient raw materials for blood production afterward can reduce red blood cell production and oxygen-carrying capacity, leading to organ hypoxia and fatigue. This may be accompanied by pallor, dizziness, and palpitations. Patients may use medications such as ferrous succinate tablets, vitamin B12 injections, or compound ejiao syrup under medical guidance to improve symptoms.
In daily care, ensure sufficient sleep and avoid staying up late; gradually increase activity levels according to recovery progress and avoid overexertion; maintain a positive mood and reduce anxiety; pay attention to wound care to prevent infection.
