Instruct: Given a question, retrieve passages that can help answer the question.
Query: What is the typical age of onset for male pattern baldness?
Treatment of pattern hair loss may simply involve accepting the condition.[3] Interventions that can be tried include the medications minoxidil (or finasteride) and hair transplant surgery.[4][5] Alopecia areata may be treated by steroid injections in the affected area, but these need to be frequently repeated to be effective.[3] Hair loss is a common problem.[3] Pattern hair loss by age 50 affects about half of males and a quarter of females.[3] About 2% of people develop alopecia areata at some point in time.[3]
Conduct disorder is diagnosed based on a prolonged pattern of antisocial behavior in childhood and/or adolescence, and may be seen as a precursor to ASPD. Some researchers have speculated that there are two subtypes of conduct disorder which mark dual developmental pathways to adult psychopathy. The DSM allows differentiating between childhood onset before age 10 and adolescent onset at age 10 and later. Childhood onset is argued to be more due to a personality disorder caused by neurological deficits interacting with an adverse environment. For many, but not all, childhood onset is associated with what is in Terrie Moffitt's developmental theory of crime referred to as "life-course- persistent" antisocial behavior as well as poorer health and economic status. Adolescent onset is argued to more typically be associated with short-term antisocial behavior.
Calves and juveniles less than a year old are typically unspotted and bear a grey coloration. Subadults slowly develop a "mottled" or "speckled" coating between the ages of 4 and 20, with females experiencing an earlier onset of this pattern development compared to males. After the age of 25, adults begin to slowly lose this spotted pattern and, once again, females experience an earlier onset and drastically faster rate of loss when compared to males.
Schizophrenia is diagnosed 1.4 times more frequently in males than females, and typically appears earlier in men[7]—the peak ages of onset are 20–28 years for males and 26–32 years for females.[8] Onset in childhood is much rarer,[9] as is onset in middle- or old age.[10]
The typical age of onset is 20–40. It is unknown why males are predominantly affected, with rates in males being 17- to 70-fold those in females, despite thyroid overactivity being much more common in women.
Structural follicular dysplasia varies by breed but all involve weakened hairs that break easily. Hair loss is originally seen in areas of repeated grooming or trauma, for instance the neck because of contact with a collar. Hair regrowth may occur, but the hair will be even weaker and the pattern will repeat. The dogs are affected between the ages of two to four years, and it is most commonly seen on the back towards the tail. Progression of the hair loss to cover the trunk can occur.In some breeds hair follicles in certain parts of the body become progressively miniaturized, analogous to what occurs in male pattern baldness in humans. It is most commonly seen in Dachshunds, Miniature Pinschers, and Chihuahuas. Affected areas become progressively more alopecic. The pattern of hairlessness that results is somewhat breed-dependent and sex dependent. In short-coated toy and miniature dogs, ventral neck, ventral chest, ventral abdomen and inner thighs are affected. In males, the pinnae (ear flaps) are affected. In Greyhounds, the thighs are affected as well as the ventral chest and abdomen.
There are various reasons for hair loss, most commonly hormonal issues. Fluctuations in hormones will often show in the hair. Not all hair loss is related to what is known as male pattern baldness, women can suffer from baldness just as men do. Formulas for addressing this specific cause of lack of hair growth yet typically they require around three months of consistent use for results to begin to appear. Cessation may also mean that gained growth may dissipate.
Although baldness is not as common in women as in men, the psychological effects of hair loss tend to be much greater. Typically, the frontal hairline is preserved, but the density of hair is decreased on all areas of the scalp. Previously, it was believed to be caused by testosterone just as in male baldness, but most women who lose hair have normal testosterone levels.
Bursts of generalized spike-and-wave discharges lasting two seconds or longer is considered an absence seizure. Absence seizures are generalized epileptic seizures that can be divided into two types, typical and atypical. Typical and atypical absence seizures display two different kinds of spike-and-wave patterns. Typical absence seizures are described by generalized spike-and-wave patterns on an EEG with a discharge of 2.5 Hz or greater. They can be characterized by an increase in synchronization of discharges in the thalamocortical circuitry. They can also be characterized by the acute onset and termination of the seizure. Atypical absence seizures have a higher frequency in children with severe epilepsy that suffer from multiple types of seizures. The spike-and-wave pattern seen here is more irregular than the generalized pattern and also seems to be slower. This irregular pattern is due to non-synchronous discharges of the thalamocortical circuitry. The onset and termination in these atypical absence seizures seem to be less acute than the typical absence seizures.
Centauri males of high social status typically wear their hair in Peacock-tail shaped fans, the length and style of which are determined by relative social class. Low-class Centauri males have not been seen without helmets. Centauri females mostly or entirely shave their heads. The social significance (if any) of complete versus almost-complete baldness on a female is not specified outright; however, in the televised episodes, older females are shown completely bald, and younger (up to the apparent human age range of the 30s, and often but not always unmarried) with ponytails.
The average age at onset is 3–7 years, but CVS has been seen in infants who are as young as 6 days and in adults who are as old as 73 years. Typical delay in diagnosis from onset of symptoms is 2.7–3 years. Females show a slight predominance over males; the female-to-male ratio is 57:43.
In 1942, James Hamilton observed that prepubertal castration prevents the later development of male pattern baldness in mature men. In 1974, Julianne Imperato-McGinley of Cornell Medical College in New York attended a conference on birth defects. She reported on a group of intersex children in the Caribbean who appeared sexually ambiguous at birth, and were initially raised as girls, but then grew external male genitalia and other masculine characteristic after onset of puberty. These children, despite being raised as girls until puberty, were generally heterosexual, and were termed "Guevedoces" by their local community, which means "penis at twelve" in Spanish. Her research group found these children shared a genetic mutation, causing deficiency of the 5α-reductase enzyme and male hormone dihydrotestosterone (DHT), which was found to have been the etiology behind abnormalities in male sexual development. Upon maturation, these individuals were observed to have smaller prostates which were underdeveloped, and were also observed to lack incidence of male pattern baldness.
Although men grow hair faster than women, baldness is much more common in males than in females. The main cause for this is "male pattern baldness" or androgenic alopecia. Male pattern baldness is a condition where hair starts to get lost in a typical pattern of receding hairline and hair thinning on the crown, and is caused by hormones and genetic predisposition.
Castrations after the onset of puberty will typically reduce the sex drive considerably or eliminate it altogether. Castrated people are automatically sterile, because the testes (for males) and ovaries (for females) produce sex cells needed for sexual reproduction. Once removed, the subject is infertile. The voice does not change. Some castrated people report mood changes, such as depression or a more serene outlook on life, although this might not be due to chemical changes but instead emotional changes due to the implications of the procedure. Body strength and muscle mass can decrease somewhat. Body hair may sometimes decrease. Castration prevents male pattern baldness if it is done before hair is lost. However, castration will not restore hair growth after hair has already been lost due to male pattern baldness.
Healthy hair indicates health and youth (important in evolutionary biology). Hair color and texture can be a sign of ethnic ancestry. Facial hair is a sign of puberty in men. White hair is a sign of age or genetics, which may be concealed with hair dye (not easily for some), although many prefer to assume it (especially if it is a poliosis characteristic of the person since childhood). Male pattern baldness is a sign of age, which may be concealed with a toupee, hats, or religious and cultural adornments. Although drugs and medical procedures exist for the treatment of baldness, many balding men simply shave their heads. In early modern China, the queue was a male hairstyle worn by the Manchus from central Manchuria and the Han Chinese during the Qing dynasty; hair on the front of the head was shaved off above the temples every ten days, mimicking male-pattern baldness, and the rest of the hair braided into a long pigtail.
Trichotillomania is diagnosed in all age groups; onset is more common during preadolescence and young adulthood, with mean age of onset between 9 and 13 years of age, and a notable peak at 12–13. Among preschool children the genders are equally represented; there appears to be a female predominance among preadolescents to young adults, with between 70% and 93% of patients being female. Among adults, females typically outnumber males by 3 to 1.
This species breeds from September to November. Typically, the female goral enters estrus at the age of 1.5 years and gives birth at 2 years of age, whereas males first show rutting behavior and mating at 3 years of age. During the rut, males will follow females closely, being in frequent nasogenital contact (often accompanied by smelling and licking) to determine the onset of estrus. Non-receptive females will either flee from the advances of males or threaten them by butting the bodies of the males with their heads. Receptive females tend to stand still as the male approaches, signalling their estrus by raising their tails. The Flehmen response (lip curl) was observed during the majority of encounters between a male and a receptive female.
In some cases, the age of onset may be the result of mutation accumulation. If this is the case, it could be helpful to consider ages of onset as a product of the hypotheses depicted in theories of aging. Even some mental health disorders, whose ages of onset have been found to be harder to define than physical illnesses may have a mutated component. The symptoms of standard mental disorders often start off non-specific. Pathological changes pertaining to disorders often become more detailed and less fickle before they can be defined in the American Psychiatric Association's DSM. The brain is a dynamic and complex system, it is constantly re-wiring itself and a major concern is what happens to the brain in earlier life that mirrors what occurs later in its psycho-pathological state. The typical onset of many mental disorders in late adolescence may reflect the critical development that happens at this time.
There are two types of identification tests for female pattern baldness: the Ludwig Scale and the Savin Scale. Both track the progress of diffused thinning, which typically begins on the crown of the head behind the hairline, and becomes gradually more pronounced. For male pattern baldness, the Hamilton–Norwood scale tracks the progress of a receding hairline and/or a thinning crown, through to a horseshoe-shaped ring of hair around the head and on to total baldness.
Beyond looking at the genes and individual proteins that play a role in primary focal hyperhidrosis, researchers have looked at the patterns of heredity for this trait. In a 2003 study, using multiple families, researchers found that primary focal hyperhidrosis was not a sex-linked gene, since male-to-male transmission was seen in multiple families. Instead evidence supported an autosomal dominant pattern of inheritance with an incomplete disease penetrance. 21 patients in this study reported a positive family history of hyperhidrosis (62%). Researchers were able to uncover this by creating pedigrees of all the participants in the study. Not every member of the pedigree exhibited forms of hyperhidrosis, which allowed the researchers to track the patterns of inheritance. The findings in this study indicated that primary focal hyperhidrosis is typically an hereditary disorder.
Typical regions of excessive sweating include the hand palms, underarms, the sole of the foot, and sometimes groin, face, and scalp. Indeed, profuse sweating is present mostly in the underarms, followed by the feet, palms and facial region. Sweating patterns of focal hyperhidrosis are typically bilateral or symmetric and rarely occur in just one palm or one underarm. Night sweats or sweating while sleeping is also rare. The onset of focal hyperhidrosis is usually before the age of 25 years. This is in contrast to generalized hyperhidrosis which tends to occur in an older age group.
Male pattern hair loss is also known as androgenic alopecia, androgenetic alopecia (AGA), alopecia androgenetica, and male pattern baldness (MPB).
The second developmental course is known as the "adolescent-onset type" and occurs when conduct disorder symptoms are present after the age of 10 years. Individuals with adolescent-onset conduct disorder exhibit less impairment than those with the childhood-onset type and are not characterized by similar psychopathology. At times, these individuals will remit in their deviant patterns before adulthood. Research has shown that there is a greater number of children with adolescent-onset conduct disorder than those with childhood-onset, suggesting that adolescent-onset conduct disorder is an exaggeration of developmental behaviors that are typically seen in adolescence, such as rebellion against authority figures and rejection of conventional values. However, this argument is not established and empirical research suggests that these subgroups are not as valid as once thought.
Anorexia nervosa is characterized by the severe restriction of food intake that results in a significant weight loss. There are two subtypes of anorexia, restricting type and binge-eating/purging type. While historically researchers have found that anorexia typically begins during puberty, recent epidemiological studies have found that the average age of onset of anorexia nervosa has moved from the previously from an average age of onset of 13–17 to a current younger age of onset of 9–12. Among individuals with an eating disorder, 86% report the onset of the eating disorder by age 20, and 43% report the onset between the ages of 16 and 20.6. Corresponding with the age of onset, 95% of the population with current eating disorders are between the ages of 12 and 25.
The role of infection by the virus is influenced by the climate and geographical characteristics which favor the life of the dermatophyte as dictated by the average rainfall rate and average air temperatures. There tends to be a greater number of infections in later seasons as emphasis is placed on age, sex, months of onset of infection, and marked localization of the fungus. Adults, particularly males are typically infected, and of those infected usually involved in agricultural practices, such as greenhouses and plant nursery workers. School-age males are more prone than females because of contact in the soil. Onset of infection usually occurs from August to November, when humans come into contact with soil more often.
Research is looking into connections between hair loss and other health issues. While there has been speculation about a connection between early-onset male pattern hair loss and heart disease, a review of articles from 1954 to 1999 found no conclusive connection between baldness and coronary artery disease. The dermatologists who conducted the review suggested further study was needed.[43]