烦者，心烦乱不安；躁者，手足扰动不宁也。大概皆火之为病。五脏之火，皆
令烦躁，故或言心热，或言脾热、肺热、肾热、肝热也。而有分烦为阳躁为阴者，
以阳火内生，心为热所乘，恶其扰乱，故烦闷。非甚而狂越，则不必手足之扰动，
盖火在内而不在外也。若阴寒内生，逼阳于外，中寒而外则热，热在外而不在内，
故但手足躁扰而心不必烦也，此阴阳以寒热分也。又心火为阳，火盛则烦；肾火为
阴，火炎则躁，此阴阳以心肾分也。又人将死，则手足扰乱急遽，毫无和缓之象，
（此与真脏脉弦强挺劲毫无胃气同理。）是名鬼躁，亦阴象也。烦，有实有虚。虚烦者，或气虚，
或血虚也。血虚则无以养心，而怔忡不宁，不得寐则烦矣。气虚则火旺，（东垣所谓邪
火与元气不两立，此衰则彼旺是也。）故乘心而烦也。治法∶热在心肺，起卧不安，宜栀子豉
汤、竹叶石膏汤、竹茹汤、朱砂安神丸。下利后更烦，栀子豉汤。身热，汗出烦不
解，名风厥。太阳伤风则发烦热，曰风；少阴之热亦上冲，故汗出不解，曰厥。
《经》谓∶表里刺之，（太阳为表，少阴为里。）饮以汤。（止其上逆之气也。仲景麦门冬
汤之烦。）不烦而
心手极热，喜居阴处，脉沉口渴，妙香丸下其热痰。不得眠，温胆汤（见惊）、酸枣汤。
（见不得卧。）津耗者，生其津。血耗者，补其血。肾水竭者，滋肾。产、痘、滞下后，
血液耗散，心烦不安，危矣，猛进独参汤。心中蕴热，清心莲子饮。（见赤白浊。）虚烦
有身热，与伤寒相似，但头身不痛，不恶寒，脉不紧为异。阴躁，欲裸衣坐井中，
以热药治之，四逆（见厥）、理中（见中寒）之类。
烦，是指心中烦乱不安；躁，是指手足躁动不宁。大体上都是火邪致病。五脏之火，都能导致烦躁，所以有时说心热，有时说脾热、肺热、肾热、肝热。
有一种观点将“烦”归为阳证，“躁”归为阴证，理由是：阳火内生，心被热邪所乘，厌恶其扰乱，所以感到烦闷。除非病情严重到狂乱越常，否则不需要手足扰动，这是因为火在体内而不在体表。如果是阴寒内生，逼迫阳气外浮，内部寒冷而外部发热，热在体表而不在体内，所以只是手足躁扰而心中不一定烦闷，这是以寒热来区分阴阳。
又有一种说法认为：心火属阳，火盛则烦；肾火（命门之火）属阴，火炎则躁，这是以心肾来区分阴阳。
另外，人临死前，手足慌乱急促，毫无和缓之象（这与真脏脉弦强挺劲、毫无胃气的道理相同），这叫做“鬼躁”，也是阴证的征象。
烦，有实证和虚证之分。虚烦，或是气虚，或是血虚。血虚则无法滋养心脏，导致心悸不宁，失眠从而产生烦闷。气虚则火旺（李东垣所谓邪火与元气不能两立，元气衰则邪火旺），因此邪火乘袭心脏而导致烦闷。
治疗方法：若热在心肺，坐卧不安，宜用栀子豉汤、竹叶石膏汤、竹茹汤、朱砂安神丸。下利之后更加烦闷，用栀子豉汤。身体发热，出汗后烦闷不解，称为风厥。太阳经受伤风则发烦热，称为风；少阴经的热邪也向上冲逆，所以出汗后症状不解，称为厥。《内经》说：表里同刺（太阳为表，少阴为里），并服用汤药（以止其上逆之气。参考张仲景麦门冬汤治疗烦闷的用法）。如果不烦但心部和手部极热，喜欢待在阴凉处，脉沉且口渴，用妙香丸泻下热痰。失眠，用温胆汤（见惊悸条）、酸枣仁汤（见不得卧条）。津液耗损者，滋生津液。血液耗损者，补益血液。肾水枯竭者，滋补肾阴。产后、痘疹、痢疾之后，血液耗散，心烦不安，病情危重，应猛进独参汤。心中蕴积热邪，用清心莲子饮（见赤白浊条）。虚烦伴有身热，与伤寒相似，但头身不痛，不恶寒，脉不紧，以此作为区别。阴躁，想要脱衣坐在井中，用热性药物治疗，如四逆汤（见厥条）、理中汤（见中寒条）之类。
Fan (irritability/restlessness of mind) refers to mental agitation and unease; Zao (restlessness of limbs) refers to the restless movement of the hands and feet. Generally, these are caused by Fire pathogenic factors. The Fire of the Five Viscera can all cause Fan and Zao; thus, it is sometimes referred to as Heart Heat, Spleen Heat, Lung Heat, Kidney Heat, or Liver Heat.
Some distinguish Fan as Yang and Zao as Yin. This is because when Yang-Fire arises internally, the Heart is invaded by Heat, which causes aversion to disturbance, resulting in a sensation of stifling irritability (Fan). Unless the condition is severe enough to cause mania and loss of control, there is no need for restlessness of the limbs, as the Fire is internal rather than external. Conversely, if Yin-Cold arises internally and forces Yang to float outward, the interior becomes cold while the exterior becomes hot. Since the Heat is external rather than internal, there is only restlessness of the limbs without necessarily feeling mentally irritable. This distinction classifies Yin and Yang based on Cold and Heat.
Another view holds that Heart Fire belongs to Yang, and excessive Fire causes Fan; whereas Kidney Fire (Mingmen Fire) belongs to Yin, and flaming Fire causes Zao. This classification distinguishes Yin and Yang based on the Heart and Kidney.
Furthermore, when a person is near death, the hands and feet move chaotically and urgently, lacking any sign of relaxation (this is analogous to the True Zang pulse being wiry, strong, and stiff, devoid of Stomach Qi). This is called "Ghost Zao" (Gui Zao), which is also a sign of Yin syndrome.
Fan can be either Excess or Deficiency. Deficient Fan is caused by either Qi deficiency or Blood deficiency. When Blood is deficient, it fails to nourish the Heart, leading to palpitations and unrest, insomnia, and subsequently Fan. When Qi is deficient, Fire flares up (as Li Dongyuan stated: Evil Fire and Healthy Qi cannot coexist; as one declines, the other rises). Thus, Evil Fire invades the Heart causing Fan.
Treatment methods: If Heat is in the Heart and Lungs, causing restlessness in sitting and lying down, use Zhizi Chi Tang (Gardenia and Fermented Soybean Decoction), Zhuye Shigao Tang (Bamboo Leaf and Gypsum Decoction), Zhuru Tang (Bamboo Rind Decoction), or Zhusha Anshen Wan (Cinnabar Calming the Spirit Pill). If irritability worsens after diarrhea, use Zhizi Chi Tang. If body heat persists and irritability does not resolve after sweating, it is named Feng Jue (Wind Jue). Taiyang (Solar Channel) wind-strike causes Fan and heat, termed Wind; Shaoyin (Yin Mini) Heat also rushes upward, so symptoms do not resolve with sweating, termed Jue. The Classic states: Treat both the Exterior and Interior via acupuncture (Taiyang is the Exterior, Shaoyin is the Interior), and administer decoctions (to stop the rebellious Qi rising upward. Refer to Zhang Zhongjing's Maidong Tang for treating Fan). If there is no Fan but extreme heat in the Heart and hands, a preference for cool places, a deep pulse, and thirst, use Miaoxiang Wan to purge Phlegm-Heat. For insomnia, use Wendan Tang (see Palpitations) and Suanzaoren Tang (see Inability to Sleep). If Body Fluids are depleted, generate fluids. If Blood is depleted, tonify Blood. If Kidney Water is exhausted, nourish the Kidney. After childbirth, smallpox, or dysentery, if Blood is depleted and scattered, causing mental irritability and unrest, the condition is critical; vigorously administer Dushen Tang (Single Ginseng Decoction). If Heat accumulates in the Heart, use Qingxin Lianzi Yin (Clear the Heart Lotus Seed Drink). (See Red and White Turbidity.) Deficient Fan with body heat resembles Shanghan (Cold Damage), but differs in that there is no headache or body pain, no aversion to cold, and the pulse is not tight. Yin Zao manifests as a desire to strip clothes and sit in a well; treat with warming herbs, such as Sini Tang (Reverse the Yield Decoction) (see Jue) and Lizhong Tang (Regulate the Middle Decoction) (see Middle Cold).