Taking a shower can cause one knee to hurt because the bending motion required to get in and out of the shower, combined with the warm water, can exacerbate existing knee conditions like arthritis, injuries, or inflammation, putting stress on the joint and causing pain, especially if the knee is already sensitive or has fluid buildup. Key reasons why showering might cause knee pain: Joint stress: Bending the knee while showering puts pressure on the joint cartilage, which can be painful for people with arthritis or other degenerative joint conditions. Fluid shift: Warm water can cause fluid to accumulate around the knee joint, leading to swelling and discomfort. Muscle tension: The positioning needed to shower can strain surrounding muscles, contributing to knee pain. Previous injuries: If you've had a previous knee injury, the stress of showering can irritate the healing tissues and cause pain. What to do if your knee hurts while showering: Adjust water temperature: Use lukewarm water instead of hot, as heat can increase inflammation. Use a shower chair: Sitting down while showering can reduce the strain on your knees. Gentle stretching: Before showering, do light stretches to warm up your muscles and improve flexibility. Ice pack: After showering, apply an ice pack to the affected knee to reduce swelling and pain. When to see a doctor: If the knee pain is severe, sudden, or accompanied by swelling, redness, or locking. If the pain significantly impacts your daily activities. If you suspect you have a serious knee injury.
我没有答案，只是感到困惑。
某君60岁左右，单侧膝关节有一点儿问题，不是很严重。奇怪的是每次淋浴（热水）超过五分钟那个膝关节就会剧痛，洗澡后疼痛会持续一个小时左右才缓解，和洗热水澡或泡澡可以缓解疼痛的一般说法恰恰相反。
我问他是否用了什么特殊的洗发水或沐浴液（因为我自己这几年对植物精油过敏）？他说用不用洗发水和沐浴液都一样。
这个问题不是偶然发生而是次次发生。
这是什么因果关系？
Reddit 上有人贴出相同的问题，似乎无解。
一个是足弓，一个是骨盆。
原本足弓歪斜（大概率是往内侧歪斜）并且卡住会让小腿的胫前肌和比目鱼肌向内旋转，这样大腿的肌肉就会向外旋，在膝盖的地方形成一个扭曲的力，因此会有膝盖不适的问题。
洗澡可以让上半身明显放松，而下半身因为是站着，所以放松不明显，因此骨盆周围的肌肉，例如臀部肌肉和腹直肌放松比较明显。这部分肌肉原本是拉着股四头肌形成一个动态的平衡，热水放松了这些肌肉之后就可以让股四头肌外旋加重，因此膝盖处张力反而过大就更加疼痛了。
治疗上把足弓拆开，复位卡住的筋膜基本上就可以不痛。然后再旋正小腿和大腿的肌肉，让股骨复位，基本上整个人的运动状态就可以很轻松了。
所以西医的理疗一般用冰敷减轻炎症和疼痛
泡澡是在浴缸里坐着，下半身会比站着放松。
我见过无数中医针灸高手（接近四位数），尚且没有见过谁能治疗这种慢行膝盖疼痛，在停止治疗后让病人保持不痛超过2周的。
您行吗？
脚上的骨头之间本来位置就很有限，可以获得的缓解空间远小于上半身的肌肉。
但是泡脚确是可以有缓解的机会。
而那种疼远远没有洗澡时出现的疼那么厉害。
我在乱猜，会不会有主动脉瘤之类的更可怕的东西？已经建议他去医院检查。
但是中医是基于模型的，内经也是基于模型的，随着时间的迁移，科学的发展，现代生理学已经补充了很多内经中模型的不足。
不学内经是假中医，不学现代生理学和解剖，是瘸腿中医。
人体是老老实实的东西，不了解人体结构，谈什么看病。
疼痛部位是非正常组织状态，组织变性、僵化失去弹性，或者有代谢物沉积。导致的病因多样，但是其结果都是疼痛部位没有正常的血液循环通路。气血得温则行，血流加快，来不及从其他通路循环，形成冲击疼痛。
少数人内服温通中药治疗“久痹疼痛”也会出现类似状况，如果配合针灸或者其它理疗可以避免或减轻。和热水的区别是，剧烈疼痛通常只是在第1次服药时出现，而且痛过后患处有轻快感，灵活度和疼痛比服药前都有所改善。
和现代中医院校的教材相比，内经是更高的无形气运层次，理解内经，需要对自然界的感悟力以及逻辑思考能力。气运是宇宙的本源，模型可以万般演绎，本源始终如一。体悟内经，对各个行业都能有所启发，不仅仅是中医。
Taking a shower can cause one knee to hurt because the bending motion required to get in and out of the shower, combined with the warm water, can exacerbate existing knee conditions like arthritis, injuries, or inflammation, putting stress on the joint and causing pain, especially if the knee is already sensitive or has fluid buildup. Key reasons why showering might cause knee pain: Joint stress: Bending the knee while showering puts pressure on the joint cartilage, which can be painful for people with arthritis or other degenerative joint conditions. Fluid shift: Warm water can cause fluid to accumulate around the knee joint, leading to swelling and discomfort. Muscle tension: The positioning needed to shower can strain surrounding muscles, contributing to knee pain. Previous injuries: If you've had a previous knee injury, the stress of showering can irritate the healing tissues and cause pain. What to do if your knee hurts while showering: Adjust water temperature: Use lukewarm water instead of hot, as heat can increase inflammation. Use a shower chair: Sitting down while showering can reduce the strain on your knees. Gentle stretching: Before showering, do light stretches to warm up your muscles and improve flexibility. Ice pack: After showering, apply an ice pack to the affected knee to reduce swelling and pain. When to see a doctor: If the knee pain is severe, sudden, or accompanied by swelling, redness, or locking. If the pain significantly impacts your daily activities. If you suspect you have a serious knee injury.