What your hair is trying to tell you about your health

The condition of your hair is often a snapshot of your internal wellness, indicating everything from high stress levels to nutritional deficiencies in your diet.

Likewise, there is a strong interplay between a healthy scalp and healthy hair. When the scalp is thrown out of balance as a result of hormones, vitamin deficiencies, stress and pollution levels, it can affect the blood circulation to the follicles. Ergo, hair growth is stunted.

The trouble is, because hair is a non-essential tissue, your body will never naturally send extra reinforcements its way if you are lacking in any particular vitamin or mineral. So it may be time to stage an intervention of your own.

For Sacha Mitic, co-founder of Swedish haircare brand Sachajuan, “your skin doesn’t simply stop at your forehead." So it follows that see-sawing temperatures – air-con in summer; central heating and blasts of arctic wind in winter – can leave both the skin on your face and scalp sapped of moisture.

Stress can also cause an itchy scalp as it disrupts the skin's barrier function, causing moisture to escape through the microscopic cracks. "This can spark flaking and itching in those who are pre-disposed to dandruff," says consultant trichologist Anabel Kingsley, noting that certain foods can exacerbate scalp conditions, too, including full-fat dairy products, sugary treats and a lack of omega 3s, which are nature's anti-inflammatory.

However the main culprits are dandruff and seborrhoeic dermatitis. "Dandruff is a fungal (or yeast) condition," explains Kingsley. "It usually occurs when the microbiome of your scalp becomes imbalanced. When a certain normal species of fungus called the malassezia yeasts overgrow, this can cause skin cells to divide too rapidly – leading to tell-tale flakes and itching."

So what can be done? Scalps suffering from dry skin and dandruff are both crying our for exfoliation. For an invigorating manual scrub, look no further than Philip Kingsley Density Stimulating Scalp Mask, while salicylic acid is the chemical exfoliator of choice. The Inkey List Salicylic Acid Exfoliating Scalp Treatment swiftly re-establishes equilibrium and calms irritation.

Those with parched scalps should also up their intake of omega 3 found in walnuts, flaxseeds and oily fish such as salmon and sardines. Product-wise, Sachajuan's Scalp Conditioner is great for hitting the sweet spot of gently reducing skin shedding with salicylic acid, while cold water algae extracts nourish.
"Add a hair mask into your routine once a week if needed or apply a leave-in cream to fight frizz and lock in hydration,” says Johan Hellström, CEO and founder of Björn Axén, who recommends the Björn Axén Signature The Leave In Cream, enriched with macadamia oil and provitamin B5.

Dandruff, however is not a dry scalp condition, warns Kingsley, it's almost always an oily one. "So applying hair oils in a bid to clear them simply results in stickier, greasier flakes," she adds. Instead, scan the ingredients list on your shampoo for camphor (soothing and cooling), zinc PCA (anti-itching) and anti-microbial piroctone olamine, which targets the Malassezia yeasts.

The point of shampoo hair is to lift away daily grime and product residue, but in doing so you also inevitably strip the strands of moisture. This is especially problematic for those with curly and Afro-textured hair, which need plenty of moisture. Coils and kinks in the hair strand mean the natural oils that are produced in our hair follicles, reach the ends at a much slower rate.

As well as always following up with conditioner and scheduling in a twice weekly hair mask for extra nourishment, make a point of including enough protein in your diet. "Hair is made of protein, perhaps making this the most essential nutrient for healthy growth," says Kingsley. "Eating at least a 120g portion of protein that contains all essential amino acids [think fish, eggs, poultry, quinoa or nuts] is ideal.

Timing your protein intake is also an exact science. According to Kingsley, "energy to form hair cells is lowest first thing in the morning so eat a balanced and nutritious breakfast consisting of proteins and complex carbohydrates to give your hair a nutritional boost."

Ferritin (a stored iron) is also needed by the body to produce hair cell protein. "Ferritin deficiency commonly causes increased hair fall and a shortening of the anagen phase of the hair growth cycle," says Kingsley. "This means hair may not be able to grow as long as it is capable of," she continues. If you eat red meat, try to do so two times a week, otherwise consider taking a hair supplement containing iron.

Telogen effluvium is a temporary type of hair loss, which Kingsley says cuts short the anagen (growth) phase of the hair cycle as a result of an imbalance in your body. This can be caused by a one-off, short-term illness like flu or a vitamin B12 deficiency and chronic stress.

First off, having good levels of vitamin B12 helps your body make enough red blood cells, which are used to transport oxygen to your hair follicles. "Without adequate oxygen, your hair follicles stop functioning properly," says Kingsley. "This can cause your hair to fall out."

Vitamin B12 also helps your body to absorb amino acids, which are the building blocks of strong, healthy hair. So it's worth adding poultry, meat, dairy and eggs to your diet or, if you're vegetarian, cereals and soy products fortified with vitamin B12.

Kingsley also supports a holistic approach to manage stress levels – for example, doing yoga. "Stress can wreak havoc on your hair growth cycle and your scalp," she says. "One reason for this is that stress can raise androgen (male hormone) levels, which can worsen or trigger female pattern hair loss if you have a genetic predisposition towards it. Stress can also make it harder for your body to absorbs nutrients."

There are a number of reasons why acne appears on your scalp – and many correlate with breakouts on your face. In fact, if you have an oily skin type you're more likely to also have an oily scalp and, as such, stress, hormonal imbalances and pore-clogging products can exacerbate spots.

As for your hair washing routine, approach it in the same way as your skincare and be aware of nuances created by your menstrual cycle. "Just before your period starts, oestrogen levels drop," says consultant dermatologist Dr Anjali Mahto. "This drives acne and causes your sebaceous glands to secrete more sebum." Look for antibacterial sulfur in your shampoo and conditioner (Ouai Detox Shampoo is a good option), while Harklinikken Stabilizing Shampoo is laced with benzoic acid, an antiseptic agent that prevents infection caused by bacteria.

Crucially, wash your hair at least every other day rather than rely on dry shampoo, which leaves a souped up coating of powder, bacteria, dead skin cells, oils and dirt on the scalp surface, blocking pores.

Remember, too, before putting on a hat, your hair needs to be completely dry, says Hellström, who recommends blow-drying on a low heat. “Wet hair under a hat isn’t good for the health of your scalp as bacteria love a damp environment.”