膝盖痈，生于膝盖，色红 肿疼痛，属湿火，为气血实。疵疽亦生在膝盖，肿大如痈，
其色不变，寒热往来，属寒凝湿滞，为气血虚。和软为顺，坚硬如石者逆。经云∶肉之小会
为溪。溪者，二肘、二膝、四腕也。凡脾病在溪；肾有邪，其气留于两膝；凡筋病皆属于节
，筋乃肝之余，故又属肝。是以溪会有病，皆从脾肾肝三经邪气乘之也。倘两膝俱生，即属
败证，不治。治法∶湿热者，宜清利解毒，萆 化毒汤主之；寒湿者，宜温散和营通络，桂
枝和营汤主之。
委中毒，生于膝湾内委中穴（穴在膝后 中央褶纹陷中），属膀胱经。经曰∶
中毒，由胆经积热流入膀胱，壅遏不行而成。夫膀胱为聚湿之所，热入混淆，注于络脉生痈
，则莫非湿热凝结为患。初起木硬肿痛微红，屈伸艰难，故又名曲鳅，寒热不退则成脓矣
。治宜清湿热、活血化瘀、舒筋散邪。若不速治，恐筋缩，遂成废疾。
膝眼毒，生于膝盖骨下两旁膝眼中，又名托疽。外侧者属足少阳胆经，内侧者属足太阴
脾经。初起必先膝眼酸痛，后乃 肿作痛成脓。系湿火注聚而成者多，亦有肾经感受风邪，
寒湿相侵而受者。其寒湿、湿火之别，一则形高肿而色赤，一则形微肿而色白。必细认清楚
，然后施治，始无差误。
膝盖痈，发生在膝盖部位，表现为皮肤颜色红、肿胀且疼痛，属于湿火证，病机为气血实证。疵疽也生长在膝盖处，肿胀程度如同痈，但肤色没有改变，伴有寒热交替的症状，属于寒凝湿滞证，病机为气血虚证。局部触之柔软为顺证，坚硬如石头则为逆证。《内经》记载：“肌肉之间的小会合处称为溪。”所谓的“溪”，指的是双侧肘部、双侧膝部和双侧腕部（共六个部位）。凡是脾脏病变多反映在溪；肾脏有邪气时，其病气常停留于双膝；凡是筋的病变都归属于关节，因为筋是肝脏功能的余绪，所以又归属于肝。因此，溪与会合之处发生疾病，都是由于脾、肾、肝三经的邪气侵袭所致。如果双膝同时发病，即属于败证，难以治愈。治疗方法：对于湿热证，适宜采用清热利湿解毒法，以萆薢化毒汤为主方；对于寒湿证，适宜采用温散寒湿、调和营卫、疏通经络法，以桂枝和营汤为主方。
委中毒，发生在膝关节后方的委中穴处（该穴位位于膝盖后方中央褶皱的凹陷中），归属于足太阳膀胱经。医经指出：委中毒，是由胆经积热流入膀胱，导致气机壅滞不通而形成的。膀胱是聚集湿气的场所，热邪进入后与湿气混淆，灌注于络脉而生痈，这无非是湿热凝结造成的危害。初起时局部木质样坚硬、肿痛且微红，屈伸困难，因此又名“曲鳅”；若寒热症状不退，则会化脓。治疗应当清利湿热、活血化瘀、舒筋散邪。如果不迅速治疗，恐怕会导致筋脉收缩，最终成为废疾。
膝眼毒，发生在膝盖骨下方两侧的膝眼处，又名托疽。外侧者归属于足少阳胆经，内侧者归属于足太阴脾经。初起时必然先出现膝眼酸痛，随后肿胀作痛并化脓。大多由湿火注聚而成，也有因肾经感受风邪，寒湿相互侵扰而患病的。寒湿证与湿火证的区别在于：前者形态高肿且颜色发红，后者形态轻微肿胀且颜色发白。必须仔细辨认清楚，然后施治，才不会出错。
Knee carbuncle (Xigai Yong) occurs at the knee, presenting with redness, swelling, and pain. It belongs to damp-heat fire syndrome and is characterized by an excess condition of Qi and Blood. Ciju (Cigu, a type of deep-seated abscess) also grows on the knee; it swells like a carbuncle but the skin color remains unchanged, accompanied by alternating chills and fever. It belongs to cold coagulation and damp stagnation syndrome, characterized by a deficiency condition of Qi and Blood. Softness upon palpation indicates a favorable prognosis (Shun), while hardness like stone indicates an unfavorable prognosis (Ni). The Classics state: "The small junctions of muscles are called Xi." The so-called "Xi" refers to the two elbows, two knees, and two wrists. Generally, Spleen diseases manifest in the Xi; when the Kidney has pathogenic factors, their Qi tends to remain in both knees; all tendon diseases belong to the joints. Since tendons are the surplus of the Liver, they also belong to the Liver. Therefore, diseases occurring at the Xi and junctions are caused by pathogenic factors from the Spleen, Kidney, and Liver meridians attacking these areas. If both knees are affected simultaneously, it constitutes a failure syndrome (Bai Zheng) and is difficult to treat. Treatment methods: For damp-heat syndromes, clearing heat, promoting diuresis, and detoxifying are appropriate, primarily using Bixie Huadu Decoction (Dioscorea Hypoglauca Detoxification Decoction); for cold-damp syndromes, warming to dispel cold, harmonizing Ying (Nutritive) Qi, and unblocking collaterals are appropriate, primarily using Guizhi Heying Decoction (Cinnamon Twig Harmonizing Nutritive Qi Decoction).
Weizhong abscess (Weizhong Du) occurs at the Weizhong acupoint within the popliteal fossa (the point is located in the depression at the center of the posterior knee crease) and belongs to the Bladder Meridian. The Classics state: Weizhong abscess arises from accumulated heat in the Gallbladder Meridian flowing into the Bladder, causing obstruction and stagnation. The Bladder is a gathering place for dampness; when heat enters and mixes with dampness, it pours into the collaterals to form an abscess, which is invariably caused by the congealing of damp-heat. Initially, the area is woody-hard, painful, swollen, and slightly red, with difficulty in flexion and extension, hence also named "Quqiu" (Crooked Leech). If chills and fever do not subside, pus will form. Treatment should focus on clearing damp-heat, invigorating blood and resolving stasis, relaxing sinews, and dispersing pathogens. If not treated promptly, there is a risk of tendon contraction, leading to disability.
Kneeye toxin (Xiyan Du) occurs on both sides below the patella at the kneeyes, also known as Tuo Ju. The lateral side belongs to the Foot-Shaoyang Gallbladder Meridian, and the medial side belongs to the Foot-Taiyin Spleen Meridian. Initially, there must be soreness and pain in the kneeyes, followed by swelling, pain, and suppuration. It is mostly formed by the accumulation of damp-heat fire, but can also result from Wind pathogens affecting the Kidney Meridian, where cold and damp invade together. The distinction between cold-damp and damp-heat lies in morphology: the former presents with high swelling and red color, while the latter presents with slight swelling and white color. One must carefully distinguish them before treatment to avoid errors.