男性脱发原因

2020年10月10日发(作者：曹克明)
男性脱发原因
男性脱发是男性型脱发的俗称，也称雄激素源性脱发(AGA) ，在男性中十 分常见，具遗传倾
向。男性型脱发患者的头发往往先从前额两侧及顶部开始变得稀疏，导致前额发际线后 退。
脱发部位的正常头发被细的绒毛所替代，最终这些绒毛也脱落致使秃发面积逐渐扩大。[1] 现代生活的快节奏，让不少开始男性面临前所未有的压力。有调查数据显示全球年届50的
男性中超 过50%的人患有男性型脱发，男性脱发在我国的患病率为15.73%～19.75%。
原因
1. 雄性激素源性脱发
皮肤毛囊是雄激素作用的靶器官，头皮又是雄激素受体密度比较高 的部位，是雄
激素“喜欢”聚集的场所。所以雄性激素源 性脱发是最普遍的脱发类型，95%
的脱发病例属于这一类型。患雄性激素源性脱发的人血清和头皮中二氢睾酮水平
比正常人高，头皮、额部 ，特别是颞颥部和顶部 的头发在二氢睾酮的长期作用
下，毛囊表现为进行性萎缩、变小，毛发逐渐变细 、变软，颜色变淡，毛发减少。
此类型脱发的结果造成发际线消褪和头部轻度谢顶。
2. 药物导致脱发
一些处方药物可能导致某些人脱发，对癌症的治疗会使头发停止生长并在治疗期
间脱落，停药后或治疗结束后，头发有可能重新生长出来。如果在服药的初期就
发生突发性脱发，及时咨 询大夫，对治疗方案做适当改变。
3. 病理性、外科手术或疾病导致的脱发
高烧后1～3 个月，严重感染疾病或外科手术都会造成脱发；患有某些慢性病的
会持续脱发；甲状腺功能不正常也会导 致脱发；一些免疫性疾病，如头皮部位严
重的盘状红斑狼疮等，也会让头皮毛囊“很受伤”；机械性撕脱 、烧伤、慢性深
部细菌或真菌感染都会让头部“荒芜”。
4. 神经性斑秃
导 致此类型脱发的原因还不明确，此类的脱发成片状脱落，形成铜钱大小面积的
光滑、圆形秃面，神经性斑 秃应该注重精神的调养。
5.遗传原因
脱发除了和各方面的压力有关外，遗传性也是其中一个非常重要的因素。
致病原理
1、头发的生长周期
1）头发是以每月约1厘米的速度缓慢地长出来的。每根头发需生长2至 6年然
后进入休止期，最后脱落。在脱落的部位， 一般在三个月内一根新的头发可从
同一毛囊 中长出。在同一时期，约10%的头发处于休止期，而其余90%的头发处
于生长活跃期。但头发的生长 速度随着人的年 龄老化而逐渐减慢。
2）当毛囊持续萎缩时，头发会逐渐变短变细，并导致脱发，最终形成生不出头
发的微小毛囊。
2、遗传因素
男性因携带的脱发遗传基因不同，体内所分泌睾酮会在某些人的皮下组织之内经
由5a-还原酶 (5α-reductase)作用形成双氢睾酮(dihydrotestosterone，
DHT )DHT（DHT 号称毛囊杀手。强力的DHT进入细胞核，对于代谢系统产生作用。
具有细胞能量作 用的ATP物质的制造会因此而受阻。当作为热量源的ATP无法产
生出来，因 此无法进行毛发的蛋白 合成，毛母细胞失去活力，开始角质化，毛
囊开始萎缩或者坏死，头发大量进入休止期，头发就会大量脱 落。
临床诊断
脱发的医学检查：
1. 医生肉眼检查
一般情况下， 具有丰富经验的专业医生通过肉眼检查，再问问遗传、饮食、化学
品接触等问题，就知道是不是溢脂性脱 发或男性型脱发，所以不用做什么检查，
有经验的医生看看就明白。
2. 头发的牵拉检查
头发牵拉实验阳性是指在头皮的任何部位可不费力地拔落2-8根头发而无疼痛
感。休止期脱发 、生长期脱发松动综合症、斑秃等毛发病中，本实验呈阳性反应。
3. 内分泌检查
性激素 水平的检查对产后脱发、更年期脱发和口服避孕药引起的脱发，有一定的
临床意义;血清TSH的检查对 诊断甲状腺功能减退症最有价值。
4. 营养代谢检查
营养代谢性疾病如铁缺乏症，早期常 需实验室检查证实，血清铁蛋白小于12ugL
为贮铁缺乏，同时运铁蛋白饱和度小 于0.15，全血 FEP大于
1.78umolL(100ugdL)或FEPHb大于4.5uggHb的其中两项，可 确诊为缺铁性
红细胞生成性脱 发。恶性营养不良早期，由于蛋白质长期摄入不足，体内形成
负 氮平衡，血及尿中尿素氮首先下降，尿肌酸、肌酐下降也是较敏感的指标，血
浆总蛋白低下是营养不 良性脱发的确诊条件。
Male causes of hair loss
Male hair loss is commonly known as male pattern baldness, rule the roost hormone borne
alopecia (AGA) is very common in men with a genetic predisposition. The hair of male pattern
hair loss patients often start with the forehead on both sides and at the top becomes sparse,
forehead hairline. http:,Hair loss part of normal hair is fine fluff replaced by the
end of fluff off causing alopecia area gradually expanded. [1]
The fast-paced modern life, ,so many start the men facing unprecedented
pressure. The survey data show that more than 50% of the global annual session of the 50 men
suffering from male pattern hair loss, male hair loss in the prevalence rate of 15.73% to 19.75%.
Reason
1 male alopecia
Skin hair follicle androgen target organs, scalp and the higher parts of the androgen receptor
density and androgen
most common type of hair loss, ,95 percent of hair loss cases are of this type.
Suffering from alopecia of the male hormone in human serum and scalp dihydrotestosterone
levels higher than normal, scalp, forehead, temporal Ru and the top of the hair in the long-term
effects of dihydrotestosterone, hair follicles performance progressive atrophy smaller, hair
gradually tapering to soften the color fades hair reduction. The result of this type of hair loss
caused slight fade and head balding hairline.
2 drugs cause hair loss
Some prescription drugs may cause some hair loss, cancer treatment will make the hair stop
growing and fall during treatment, ,the hair may grow back after stopping or
after the end of treatment. Sudden hair loss occurs in the early stages of the medication, and
timely consultation with the doctor, treatment options to make the appropriate change.
Pathological, surgery or disease causes hair loss
1 to 3 months after a high fever, severe infection or surgery will cause hair loss; suffering from
certain chronic diseases will continue to hair loss; abnormal thyroid function can lead to hair loss;
some autoimmune diseases, such as severe scalp discoid erythema lupus, etc., but also makes
the scalp hair follicles
infection will allow the head of the
4. Nerve alopecia areata
The reason for this type of hair loss is not clear, this kind of hair loss into flaking, the formation of
the coins the size of the area of the smooth, round bald face, neurological alopecia areata should
focus on the spirit nursed back to health.
5. Genetic causes
Alopecia in addition to pressure and various aspects, hereditary also one of the very important
factors.
Pathogenic principle
1, the hair growth cycle
1) hair in a slow speed of about 1 cm per month to grow out. Each hair growth for 2-6 years and
then need to enter the telogen phase, and finally fall off. Off site, generally within three months a
new hair can grow from the same hair follicle. In the same period, about 10% of hair is in the
telogen, while the remaining 90% of hair is in the active growth period. But the hair growth rate
gradually slowed down as the aging of the human.
2) When the hair follicles continue to shrink, the hair will gradually shorter thinner and cause hair
loss final form not beget the tiny hair follicles of the hair.
2, Genetic factors
Male because of the hair loss genes carried the body the secretion of testosterone in the
subcutaneous tissue of some people through the 5a-reductase (5α-reductase) role in the
formation of DHT (dihydrotestosterone, DHT) DHT (DHT is known as the hair follicle killer. potent
DHT into the nucleus, to effect the metabolic system. , substances in the
manufacture of the role of cellular energy ATP hindered when ATP as a heat source can not be
generated, and therefore can not be the hair of protein synthesis, the hair matrix cells lose their
vitality, start keratinization, hair follicle atrophy or necrosis, hair poured into the telogen, a large
number of hair will fall off.
Clinical diagnosis
Hair loss medical examination:
1 doctor visual inspection
Under normal circumstances, with extensive experience in the professional doctors by visual
inspection, and then ask heredity, diet, chemical exposure, and you know that is not seborrheic
alopecia or male pattern hair loss, so do not do checks, experienced doctors to see explanatory.
Hair pulling check
Hair pulling test positive in any part of the scalp may from time to effortlessly pull off the the 2-8
hair without pain. Telogen effluvium, growth phase syndrome, alopecia areata, hair onset
alopecia loose, the experiment showed a positive reaction.
3. Endocrine examination
Check of the sex hormone levels of postpartum hair loss, menopause, hair loss and hair loss
caused by oral contraceptives, the clinical significance; the serum TSH check diagnosis of
hypothyroidism most valuable.
4. Nutrition metabolism checks
Nutritional and metabolic diseases such as iron deficiency, early often require laboratory tests
confirmed that the serum ferritin is less than 12ug L for the lack of ferritin, transferrin
saturation of less than 0.15, the whole blood FEP of greater than 1.78umol L ( 100ugdL) or FEP
Hb to greater than 4.5uggHb two of diagnosed with iron deficiency erythropoiesis alopecia.
The kwashiorkor early, due to the lack of long-term intake protein, the body of a negative
nitrogen balance, blood and urinary urea nitrogen first decline in urinary creatine, creatinine
decline is also more sensitive indicators, low plasma total protein malnutrition alopecia
diagnosed condition.