• Hair is produced by hair follicles, tiny cup-shaped pits found all over the skin and scalp. It contains no living tissue and is made of dead cells that have been turned into cylinders of keratin - in a similar process to nail formation. These cylinders form the hair shaft, which is extruded at a rate of about 1cm a month.
• Hair also contains fats, pigment (melanin), water (which makes up at least 10 per cent of dry hair) and traces of vitamins and minerals.
• Young children have the thickest hair, with 1,000 follicles per square centimetre. By the age of 25 that number has halved to around 500, and by the age of 50 it has halved again to around 250.
• Each follicle can produce around 20 new hairs in a lifetime which, if left uncut, will reach a metre in length before falling out.
• New-born babies' hair is shed at around two to three months of age and replaced by a second growth. This process starts at the back of the head and is responsible for the bald patch that most parents think is caused by friction from sleeping on their backs.
• Hair tends to become more pigmented with age, which is why most children's hair darkens as they get older.
IS IT NORMAL TO HAVE SO MANY HAIRS IN THE PLUG HOLE?
The average person's scalp contains as many as 150,000 hairs, up to 200 of which will be shed every day. The hairs on your scalp will be in one of three phases - a growing phase, a static phase and a shedding phase. Around 10 per cent of your scalp will be in a shedding phase at any one time and it is these hairs that tend to fall out when you wash your hair, towel it dry or brush it through.
WHAT CAUSES DANDRUFF?
Dandruff is normally caused by a yeast that thrives in the oily, warm environment of the scalp (sebum - the scalp's natural oil - is not produced in large quantities until puberty, which is why young children tend not to get dandruff). There are other conditions - including eczema and psoriasis - that can cause flaking but, in the absence of itching, soreness or redness, a low-grade fungal infection is the most likely culprit. Proprietary anti-dandruff shampoos work by controlling yeast using anti-fungal ingredients such as zinc pyrithione.
WHY DOES HAIR TURN GREY?
As we get older, pigment-producing cells (melanocytes) in the scalp stop producing your natural colouring (melanin) and the affected hairs turn white - it's the mix of white hairs with normal coloured hairs (particularly brown and black hairs) that gives the impression of greying. The lifespan of melanocytes is largely determined by genes - if your parents both turned grey in their twenties, then you are likely to follow suit. Smokers also tend to turn grey much earlier than non-smokers. Grey hair is no different structurally from pigmented hair, but it is more resistant to dyes. Contrary to the old wives' tale, plucking a single grey hair will not result in four grey ones growing back.
ARE HAIR DYES SAFE?
Around half of all women and at least one in 20 men in the UK use hair dyes, and there are concerns about the safety of some of the ingredients they contain, the most recent of which concerned a link between the regular use of darker permanent dyes and leukaemia. Researchers from the University of Illinois found that people using the dyes every two months for 15 years were two-and-a-half times more likely to develop the disease.
This new data adds to existing evidence linking permanent dyes to bladder cancer. Cancer-inducing chemicals found in some types of dye may enter the body through the skin and end up in the bladder after being filtered from the bloodstream by the kidneys. In 2001, researchers in Los Angeles published findings suggesting that women who regularly use permanent dyes are up to three times more likely to develop bladder cancer than those who don't, while hairdressers who have been in the business for more than ten years are up to five times more likely to develop the condition.
This is a controversial area - the Los Angeles findings have not been replicated in other studies - but semi-permanent dyes are probably safer as there is no convincing evidence that these cause any significant harm to health. Unfortunately, they are not as good at covering grey hairs. Allergy is another potential problem with hair dyes. Reactions can be severe but, in 15 years as a GP, I have yet to see a case.
WHY AM I LOSING MY HAIR?
The most common cause of hair loss is the genetically inherited condition alopecia androgenetica - a hormone-related form of hair loss that causes the classic receding hairline and ever-widening crown in men, and generalised thinning in women.
It is more common for men - in whom it is known as male-pattern baldness - but it is a big problem for women, too, affecting as many as one in three between the ages of 20 and 60.
This type of hair loss can be inherited from either parent and often skips a generation, making it difficult to predict who is likely to be affected.
WHAT CAN I DO ABOUT IT?
Most people with alopecia androgenetica have little choice but to learn to live with thinning hair. There are a variety of treatments available but the benefits are generally disappointing - and are lost completely unless the treatments are continued indefinitely.
The prescription pill Propecia - for men only - and the lotion Regaine are the only proven treatments which have been licensed - although many specialist hair clinics use cyproterone acetate as well. Around half of users can expect to see some improvement on using the products, but any extra hair growth disappears if the medication is stopped. Treatment with Regaine costs about 50p per day, Propecia is closer to £1 a day. Neither is available on the NHS.
WHAT ELSE CAN CAUSE HAIR LOSS?
• Autoimmune diseases can cause problems that range from patchy hair loss (alopecia areata) to the loss of every single hair on the body (alopecia universalis) but fortunately these tend to be comparatively rare.
• Localised scalp problems, including severe fungal infections, may be a cause but are generally easy to spot and treat.
• The two most commonly overlooked causes, particularly in women, are iron deficiency and thyroid problems - both can be confirmed using blood tests and are easy to correct. Hair loss in women also often tends to accelerate after the menopause - and may be slowed with HRT.
• Another cause is traction alopecia - the person pulls their hair out. This is common in teenagers and young women who use hair straighteners and/or wear their hair in a tight ponytail.
http://news.scotsman.com/features.cfm?id=564862005
:study:
• Hair also contains fats, pigment (melanin), water (which makes up at least 10 per cent of dry hair) and traces of vitamins and minerals.
• Young children have the thickest hair, with 1,000 follicles per square centimetre. By the age of 25 that number has halved to around 500, and by the age of 50 it has halved again to around 250.
• Each follicle can produce around 20 new hairs in a lifetime which, if left uncut, will reach a metre in length before falling out.
• New-born babies' hair is shed at around two to three months of age and replaced by a second growth. This process starts at the back of the head and is responsible for the bald patch that most parents think is caused by friction from sleeping on their backs.
• Hair tends to become more pigmented with age, which is why most children's hair darkens as they get older.
IS IT NORMAL TO HAVE SO MANY HAIRS IN THE PLUG HOLE?
The average person's scalp contains as many as 150,000 hairs, up to 200 of which will be shed every day. The hairs on your scalp will be in one of three phases - a growing phase, a static phase and a shedding phase. Around 10 per cent of your scalp will be in a shedding phase at any one time and it is these hairs that tend to fall out when you wash your hair, towel it dry or brush it through.
WHAT CAUSES DANDRUFF?
Dandruff is normally caused by a yeast that thrives in the oily, warm environment of the scalp (sebum - the scalp's natural oil - is not produced in large quantities until puberty, which is why young children tend not to get dandruff). There are other conditions - including eczema and psoriasis - that can cause flaking but, in the absence of itching, soreness or redness, a low-grade fungal infection is the most likely culprit. Proprietary anti-dandruff shampoos work by controlling yeast using anti-fungal ingredients such as zinc pyrithione.
WHY DOES HAIR TURN GREY?
As we get older, pigment-producing cells (melanocytes) in the scalp stop producing your natural colouring (melanin) and the affected hairs turn white - it's the mix of white hairs with normal coloured hairs (particularly brown and black hairs) that gives the impression of greying. The lifespan of melanocytes is largely determined by genes - if your parents both turned grey in their twenties, then you are likely to follow suit. Smokers also tend to turn grey much earlier than non-smokers. Grey hair is no different structurally from pigmented hair, but it is more resistant to dyes. Contrary to the old wives' tale, plucking a single grey hair will not result in four grey ones growing back.
ARE HAIR DYES SAFE?
Around half of all women and at least one in 20 men in the UK use hair dyes, and there are concerns about the safety of some of the ingredients they contain, the most recent of which concerned a link between the regular use of darker permanent dyes and leukaemia. Researchers from the University of Illinois found that people using the dyes every two months for 15 years were two-and-a-half times more likely to develop the disease.
This new data adds to existing evidence linking permanent dyes to bladder cancer. Cancer-inducing chemicals found in some types of dye may enter the body through the skin and end up in the bladder after being filtered from the bloodstream by the kidneys. In 2001, researchers in Los Angeles published findings suggesting that women who regularly use permanent dyes are up to three times more likely to develop bladder cancer than those who don't, while hairdressers who have been in the business for more than ten years are up to five times more likely to develop the condition.
This is a controversial area - the Los Angeles findings have not been replicated in other studies - but semi-permanent dyes are probably safer as there is no convincing evidence that these cause any significant harm to health. Unfortunately, they are not as good at covering grey hairs. Allergy is another potential problem with hair dyes. Reactions can be severe but, in 15 years as a GP, I have yet to see a case.
WHY AM I LOSING MY HAIR?
The most common cause of hair loss is the genetically inherited condition alopecia androgenetica - a hormone-related form of hair loss that causes the classic receding hairline and ever-widening crown in men, and generalised thinning in women.
It is more common for men - in whom it is known as male-pattern baldness - but it is a big problem for women, too, affecting as many as one in three between the ages of 20 and 60.
This type of hair loss can be inherited from either parent and often skips a generation, making it difficult to predict who is likely to be affected.
WHAT CAN I DO ABOUT IT?
Most people with alopecia androgenetica have little choice but to learn to live with thinning hair. There are a variety of treatments available but the benefits are generally disappointing - and are lost completely unless the treatments are continued indefinitely.
The prescription pill Propecia - for men only - and the lotion Regaine are the only proven treatments which have been licensed - although many specialist hair clinics use cyproterone acetate as well. Around half of users can expect to see some improvement on using the products, but any extra hair growth disappears if the medication is stopped. Treatment with Regaine costs about 50p per day, Propecia is closer to £1 a day. Neither is available on the NHS.
WHAT ELSE CAN CAUSE HAIR LOSS?
• Autoimmune diseases can cause problems that range from patchy hair loss (alopecia areata) to the loss of every single hair on the body (alopecia universalis) but fortunately these tend to be comparatively rare.
• Localised scalp problems, including severe fungal infections, may be a cause but are generally easy to spot and treat.
• The two most commonly overlooked causes, particularly in women, are iron deficiency and thyroid problems - both can be confirmed using blood tests and are easy to correct. Hair loss in women also often tends to accelerate after the menopause - and may be slowed with HRT.
• Another cause is traction alopecia - the person pulls their hair out. This is common in teenagers and young women who use hair straighteners and/or wear their hair in a tight ponytail.
http://news.scotsman.com/features.cfm?id=564862005
:study:
