Head hair comes in many colours, shapes and sizes, and hairstyles are often an expression of personal style or cultural identity.

Many different genes determine our hair texture, thickness and colour. But some people’s hair changes around the time of puberty, pregnancy or after chemotherapy.

So, what can cause hair to become curlier, thicker, thinner or grey?

Curly or straight? How hair follicle shape plays a role

Hair is made of keratin, a strong and insoluble protein. Each hair strand grows from its own hair follicle that extends deep into the skin.

Curly hair forms due to asymmetry of both the hair follicle and the keratin in the hair.

Follicles that produce curly hair are asymmetrical and curved and lie at an angle to the surface of the skin. This kinks the hair as it first grows.

The asymmetry of the hair follicle also causes the keratin to bunch up on one side of the hair strand. This pulls parts of the hair strand closer together into a curl, which maintains the curl as the hair continues to grow.

Follicles that are symmetrical, round and perpendicular to the skin surface produce straight hair.

Life changes, hair changes

Our hair undergoes repeated cycles throughout life, with different stages of growth and loss.

Each hair follicle contains stem cells, which multiply and grow into a hair strand.

Head hairs spend most of their time in the growth phase, which can last for several years. This is why head hair can grow so long.

Let’s look at the life of a single hair strand. After the growth phase is a transitional phase of about two weeks, where the hair strand stops growing. This is followed by a resting phase where the hair remains in the follicle for a few months before it naturally falls out.

The hair follicle remains in the skin and the stems cells grow a new hair to repeat the cycle.

Each hair on the scalp is replaced every three to five years.

Hormone changes during and after pregnancy alter the usual hair cycle

Many women notice their hair is thicker during pregnancy.

During pregnancy, high levels of oestrogen, progesterone and prolactin prolong the resting phase of the hair cycle. This means the hair stays in the hair follicle for longer, with less hair loss.

A drop in hormones a few months after delivery causes increased hair loss. This is due to all the hairs that remained in the resting phase during pregnancy falling out in a fairly synchronised way.

Hair can change around puberty, pregnancy or after chemotherapy

This is related to the genetics of hair shape, which is an example of incomplete dominance.

Incomplete dominance is when there is a middle version of a trait. For hair, we have curly hair and straight hair genes. But when someone has one curly hair gene and one straight hair gene, they can have wavy hair.

Hormonal changes that occur around puberty and pregnancy can affect the function of genes. This can cause the curly hair gene of someone with wavy hair to become more active. This can change their hair from wavy to curly.

Researchers have identified that activating specific genes can change hair in pigs from straight to curly.

Chemotherapy has very visible effects on hair. Chemotherapy kills rapidly dividing cells, including hair follicles, which causes hair loss. Chemotherapy can also have genetic effects that influence hair follicle shape. This can cause hair to regrow with a different shape for the first few cycles of hair regrowth.

Hormonal changes as we age also affect our hair

Throughout life, thyroid hormones are essential for production of keratin. Low levels of thyroid hormones can cause dry and brittle hair.

Oestrogen and androgens also regulate hair growth and loss, particularly as we age.

Balding in males is due to higher levels of androgens. In particular, high dihydrotestosterone (sometimes shortened to DHT), which is produced in the body from testosterone, has a role in male pattern baldness.

Some women experience female pattern hair loss. This is caused by a combination of genetic factors plus lower levels of oestrogen and higher androgens after menopause. The hair follicles become smaller and smaller until they no longer produce hairs.

Reduced function of the cells that produce melanin (the pigment that gives our hair colour) is what causes greying.

Theresa Larkin, Associate professor of Medical Sciences, University of Wollongong

This article is republished from The Conversation under a Creative Commons license. Read the original article.

There was disagreement on social media recently after a story was published about an aged care provider creating “fake-away” burgers that mimicked those from a fast-food chain, to a resident living with dementia. The man had such strict food preferences he was refusing to eat anything at meals except a burger from the franchise. This dementia symptom risks malnutrition and social isolation.

But critics of the fake burger approach labelled it trickery and deception of a vulnerable person with cognitive impairment.

Dementia is an illness that progressively robs us of memories. Although it has many forms, it is typical for short-term recall – the memory of something that happened in recent hours or days – to be lost first. As the illness progresses, people may come to increasingly “live in the past”, as distant recall gradually becomes the only memories accessible to the person. So a person in the middle or later stages of the disease may relate to the world as it once was, not how it is today.

This can make ethical care very challenging.

Is it wrong to lie?

Ethical approaches classically hold that specific actions are moral certainties, regardless of the consequences. In line with this moral absolutism, it is always wrong to lie.

But this ethical approach would require an elderly woman with dementia who continually approaches care staff looking for their long-deceased spouse to be informed their husband has passed – the objective truth.

Distress is the likely outcome, possibly accompanied by behavioural disturbance that could endanger the person or others. The person’s memory has regressed to a point earlier in their life, when their partner was still alive. To inform such a person of the death of their spouse, however gently, is to traumatise them.

And with the memory of what they have just been told likely to quickly fade, and the questioning may resume soon after. If the truth is offered again, the cycle of re-traumatisation continues.

A different approach

Most laws are examples of absolutist ethics. One must obey the law at all times. Driving above the speed limit is likely to result in punishment regardless of whether one is in a hurry to pick their child up from kindergarten or not.

Pragmatic ethics rejects the notion certain acts are always morally right or wrong. Instead, acts are evaluated in terms of their “usefulness” and social benefit, humanity, compassion or intent.

The Aged Care Act is a set of laws intended to guide the actions of aged care providers. It says, for example, psychotropic drugs (medications that affect mind and mood) should be the “last resort” in managing the behaviours and psychological symptoms of dementia.

Instead, “best practice” involves preventing behaviour before it occurs. If one can reasonably foresee a caregiver action is likely to result in behavioural disturbance, it flies in the face of best practice.

What to say when you can’t avoid a lie?

What then, becomes the best response when approached by the lady looking for her husband?

Gentle inquiries may help uncover an underlying emotional need, and point caregivers in the right direction to meet that need. Perhaps she is feeling lonely or anxious and has become focused on her husband’s whereabouts? A skilled caregiver might tailor their response, connect with her, perhaps reminisce, and providing a sense of comfort in the process.

This approach aligns with Dementia Australia guidance that carers or loved ones can use four prompts in such scenarios:

• acknowledge concern (“I can tell you’d like him to be here.”)
• suggest an alternative (“He can’t visit right now.”)
• provide reassurance (“I’m here and lots of people care about you.”)
• redirect focus (“Perhaps a walk outside or a cup of tea?”)

These things may or may not work. So, in the face of repeated questions and escalating distress, a mistruth, such as “Don’t worry, he’ll be back soon,” may be the most humane response in the circumstances.

Different realities

It is often said you can never win an argument with a person living with dementia. A lot of time, different realities are being discussed.

So, providing someone who has dementia with a “pretend” burger may well satisfy their preferences, bring joy, mitigate the risk of malnutrition, improve social engagement, and prevent a behavioural disturbance without the use of medication. This seems like the correct approach in ethical terms. On occasion, the end justifies the means.

Steve Macfarlane, Head of Clinical Services, Dementia Support Australia, & Associate Professor of Psychiatry, Monash University

This article is republished from The Conversation under a Creative Commons license. Read the original article.