The £6 shampoo shoppers are going wild for, which makes your hair grow quickly, but it won’t be in the beauty aisle

“Hair thins naturally as we get older because like our skin and muscles, the hair ages and changes,” Anabel Kingsley, trichologist at Philip Kinglsey explains. It can also be because of genetics, made worse by other health factors like menopause or thyroid disorders.

“Hair follicles very gradually shrink and produce finer and shorter strands with each passing hair growth cycle,” she adds. But while we can’t help things like genetics or the ageing process, we can do something about some of the other causes of hair thinning.

Here are four, fixable ones you need to know about.

1. Your hormones are raging
“Leading up to and during your period, the scalp may become oilier, which may trigger flaking and itching if you are predisposed to dandruff - and leaving an irritated scalp untreated can lead to hair loss,” says Anabel.

Loss of hair post-pregnancy is very common too; “After giving birth or stopping breast-feeding, oestrogen levels drop and return to normal,” Anabel explains.

“This can cause all the hairs retained during pregnancy to shed at once (usually six-12 weeks later), known as postpartum hair loss.”

Don’t panic, this is only temporary, but experts recommend you start taking daily hair supplements to support the hair’s growth.

2. Your hair can’t take the heat
“Heat drains moisture from within the hair shaft and because our hair’s elasticity and strength is largely reliant on its water content, hair can become dry, brittle and prone to breakage,” Anabel explains.

To prevent damage in the future, Anabel advises using a low setting on your heat styler, straightening only once a week and switching off your blow-dryer when your hair is just dry, as “using heat on completely dry hair will evaporate water from the hair shaft”.

3. You’re stressed
“Hair is non-essential to physical survival so it will always be the first part of you to suffer when something is off-kilter,” Anabel says.

Stress affects the scalp which can have a negative impact on the eventual health and growth of the hair. “Stress spikes cortisol levels which in turn increases oil production,” adds Anabel. “Cortisol, a stress hormone, disrupts the skin’s barrier function and triggers skin irritation which is why your scalp gets itchy and flaky when you are going through a stressful period.”

4. You’re eating the wrong food
“Diet is incredibly important to hair health,” says Anabel. “Being a non-essential tissue, hair is the last part of us to benefit from nutrients we ingest and the first to be withheld from them.”

Avoid mercury-rich fish like tuna and also full-fat dairy like cheese if you suffer from dandruff. “This can trigger flaking and itching which can then lead to hair thinning,” she says.