There are three distinct phases that each hair follicle undergoes: anagen, catagen and telogen. In the anagen (growth) phase, which can last for up to 5 years for each hair cell, the hair is growing by around 2cm per month. The catagen (rest) phase follows, wherein there is a pause in growth for around ten days. In the telogen (shed) phase, the hair is released from the follicle and then falls out, after which the follicle is dormant for three months before starting the anagen phase again. Each hair follicle goes through these cycles at a slightly different time, so hair growth and loss is constantly ongoing. In normal circumstances, you can lose eighty to one hundred hairs each day.
When these normal cycles of growth are interrupted, sudden hair loss can ensue. This may happen due to illness, changes in metabolism or dietary problems. If you are consistently losing more than 150 strands of hair each day, you should consult your GP.
Brushing, combing and styling
Your choice of hair brush can have a significant impact on the health of your hair and scalp. A brush with well-spaced, plastic bristles will be kinder to your hair than one with natural or metal bristles. Careful, gentle de-tangling of dry hair with a plastic bristle brush will have the best effect; there is no benefit to prolonged, vigorous brushing and this may in fact break your hair or scratch your scalp.
To detangle wet hair, you should use a plastic comb with wide teeth and gently work out the tangles from the ends to the roots. When blow drying, take extra care not to put too much traction on the hair as it is more likely to break with the added heat stress.
Wearing the hair in very tightly pulled styles, such as braid, weaves or even tight ponytails can cause a form of hair loss called traction alopecia. This is preventable only when such tight hairstyles are avoided at an early stage. If such styling continues in the longer term, the hair follicles will become permanently damaged resulting in permanently thinner hair or even a total lack of hair growth.
Shampoo and conditioners
The increasing choice of products for cleaning and conditioning your hair can make it difficult to find the perfect solution. Each shampoo should contain some form of detergent (such as sodium lauryl sulphate) and associated chemicals to boost the lather (often derived from coconut oil). Other chemicals listed on the label will often be to improve the perfume or to alter the colour and may have no active benefit for your hair.
How frequently you should wash your hair is often debated, with some people recommending daily washing and others eschewing shampoo altogether. Daily hair washing is often simply not possible, and you should find the happy medium that suits your lifestyle and hair type. Ensuring that all of the shampoo is rinsed out after washing is essential to maintaining a healthy head of hair.
The incorrect application of conditioner can result in lank, greasy locks, but, used properly, conditioner can vastly improve the look and feel of your hair. There are a wide range of different chemicals that can be included in conditioners, but the most common type is some form of moisturiser, which can be derived from natural oils. After shampooing, conditioner should be gently worked into the lengths and ends of hair, avoiding the scalp region, then rinsed away.
Use of hair dye
In the hands of an experienced practitioner, the use of hair dye should produce safe and excellent results. However, overuse of hair dye can at best cause hair breakage (often giving the appearance of hair loss) and at worst can cause damage to the scalp or even a serious allergic reaction. Doing a strand or patch test is very important for your own safety and for the best outcomes for your hair.
The effects of ageing
As we age, the pigmentation in our hair is gradually reduced, which results in an increasing number of non-pigmented or white hairs. The combination of these white hairs, with the normal pigmented hair results in the grey colour that is seen. At the same time, hair becomes finer and less sebum is produced, which causes the hair to have a rougher texture. Using chemical hair dyes to cover grey hair will actually exacerbate the dry, rough texture of the hair. Using regular hair masks to replace moisture, together with protection from hot styling and the sun, will improve the look and feel of grey hair.
Another common sign of ageing is thinning or loss of hair. Most men will experience thinning and hair loss in later life and this can also affect some women. Higher levels of male hormones cause more hair to grow on the face and body, and less to grow on the scalp. This is particularly pronounced for people whose hair follicles are sensitive to these hormones (or androgens) and is termed androgenic alopecia. This type of hair loss is often passed down through families.
There are a range of treatments for male pattern baldness, including drugs to restrict the action of male hormones and external treatments to either counteract the hormonal effects or to improve the appearance of the hair.
The menopause can also cause thinning and hair loss due to the decrease in the levels of oestrogen, which reduces the length of the anagen phase, causing the hair to shed before it reaches its usual length. Levels of male hormones can also increase during the menopause, causing hair to become thinner and finer. Hormone replacement therapy (HRT) can mitigate these effects but should only be taken after consultation with your GP to discuss the risks and benefits.
A distressing side effect of this treatment for many forms of cancer is the concomitant hair loss which results from the effect of chemotherapy drugs on the normal hair cycle. New techniques, such as the use of ice packs on the head to inhibit the uptake of the chemotherapy agents, can reduce this type of hair loss. In the vast majority of cases, hair will grow back after chemotherapy, but may have a different texture or colour initially.