This pattern of hair loss though is thought to be evolutionary, this is because the body holds on to hair to protect the scalp against the summer's midday sun. In the summer and spring, sun rays increase the secretion of the hormones that regulate the hairs growth. This causes a reaction similar to plants accelerated growth during the months when the weather is hot. We have greater hair loss in September, as hair has reached the end of this cycle. This hair loss however nothing to worry about: after a few weeks, everything should return to normal: the hair loss should progressively decrease, and then resume to normal.
So, should the loss be treated, or is it best to just patiently wait for end of the storm? It all depends on the state of your hair. If your hair is already tending to lose in density, it is essential to follow a supporting treatment, and it is better to begin that treatment before the loss totally settles in.
In a study published in the journal Dermatology, the scientists followed more than 800 healthy women over six years and found that they lost the most hair in the autumn months.
Even though seasonal hair loss is normal, seasonal hair loss is not the only cause of unexpected hair loss.
'Hair is an incredibly sensitive barometer,' says Glenn Lyons, consultant trichologist at the Philip Kingsley clinic, London.
'Hair cells are the second-fastest produced cells in the body (after bone marrow), so hair is often the first thing to suffer from any bodily upset. It can even forewarn you when there are no other symptoms of illness.'
That's because we don't need our hair for survival, so if it's a choice between your hair growing or keeping blood going to the vital organs, the former will suffer, explains Dr Hugh Rushton, honorary senior lecturer in trichological sciences at the University of Portsmouth.
Every year, hundreds of thousands of women - and some men - suffer from unexpected hair loss.
`You shouldn't shampoo your hair too frequently or aggressively out of worry about having an oily scalp,` said Nagaoki Wakisaka, head doctor and director of Wakisaka Clinic Osaka, a clinic specializing in hair treatments in Osaka. "[Too much shampooing] reduces the outermost layer on skin on the scalp and reduces its ability to protect the layers underneath."
When checking his patients' scalps, Wakisaka said he often finds damage due to aggressive shampooing.
To help reduce scalp damage caused by shampooing, Wakisaka recommends washing one's hair with the pads of the fingers instead of the fingertips. When shampooing, use the pads of the fingers to massage the scalp and keep the upper arms close to the torso to reduce the amount of force applied to the scalp.
The frequency of shampooing also is important.
Recently, many shampoos advertise how well they clean the hair, but products that contain surfactants to remove dirt affect the scalp's hydrolipid film, and it takes 24 hours for this film to return to normal.
Additives in water such as chlorine or water hardness also have a direct effect on the health of scalp and the hydrolipid film. Installing a shower filter to remove hardness and chlorine will support a healthy scalp that maintains it's natural oils.
People with hair or scalps that easily become smelly or oily can shampoo every day, but otherwise, once every few days is enough, Wakisaka said.
Massaging the scalp before shampooing can effectively stimulate blood flow to the area and help keep it soft. The outermost skin layer on the scalp is easily damaged when wet, so scalp massages should be performed when the skin is dry.
