What causes a feeling of weakness and fatigue in the knees?

Under normal circumstances, a feeling of weakness or fatigue in the knee may be related to factors such as overexertion, calcium deficiency, patellar chondromalacia, knee synovitis, or knee osteoarthritis. Patients are advised to promptly visit a hospital for evaluation and receive symptomatic treatment under medical guidance. Specific causes are analyzed as follows:

1. Overexertion: Excessive physical strain can lead to fatigue in the knee and surrounding muscles, resulting in lactic acid buildup and feelings of weakness. The knee and adjacent muscles may also feel sore. It is recommended to increase rest time and reduce knee load.

2. Calcium Deficiency: Insufficient calcium intake, poor absorption, or excessive loss may lead to decreased calcium levels in the body, affecting knee stability and causing weakness. Symptoms may also include nighttime muscle cramps and osteoporosis. Patients are advised to supplement calcium through foods such as milk, shrimp skins, and eggs.

3. Patellar Chondromalacia: Prolonged heavy loading and frequent bending and straightening of the knee may cause wear on the patellar cartilage, leading to chondromalacia. This condition often presents as a sensation of soreness and weakness in the knee when climbing stairs or standing up from a squat, possibly accompanied by pain in the front of the knee. Under a doctor's advice, patients may use medications such as celecoxib capsules, diclofenac diethylamine gel, or acetaminophen extended-release tablets to relieve pain.

4. Knee Synovitis: Factors such as fatigue or knee sprains may trigger knee synovitis, causing symptoms of soreness and weakness in the joint, possibly accompanied by swelling, pain, and limited mobility. Under medical guidance, patients may take medications such as ibuprofen granules, amoxicillin capsules, or methotrexate tablets to aid recovery.

5. Knee Osteoarthritis: With aging and progressive wear of knee cartilage, joint surfaces may become uneven, leading to osteoarthritis. This results in symptoms of knee soreness and weakness, often accompanied by pain, stiffness, and swelling—symptoms that worsen when climbing stairs or rising from a squat. Patients should promptly follow medical advice and use medications such as Qingpeng ointment, diclofenac sodium extended-release tablets, or clindamycin hydrochloride tablets for treatment.

During treatment, patients should maintain a positive mood and avoid emotional excitement. Additionally, they should maintain regular rest schedules and avoid overexertion.