Think of your scalp as a flowerbed. Just as you need healthy soil to nurture plants, you require a healthy scalp to grow beautiful hair. If you're having a bad hair day (or a bad hair month), ask yourself: Is your beauty routine to blame, or does your scalp need help?

Don't shun shampoo
Sorry, ladies. Despite all the hearsay to the contrary, doctors insist that washing hair less often won't train your scalp to produce less oil over time. In fact, it can exacerbate skin conditions such as dandruff. "The factory in your scalp that produces oil is in a gland deep in the scalp, and that oil gland couldn't care less about how often you rinse a little water on the surface," says Dr. Jeff Donovan, a Toronto dermatologist. To counteract dry hair caused by washing, always massage shampoo into your roots and conditioner into the strands.

Identify the problem
While dandruff might be the most common scalp irritant, eczema and psoriasis could also be the cause of flakes and irritation. If there are dry, itchy skin rashes on other areas of your body, you probably have atopic dermatitis, a type of eczema. Treat this with anti-inflammatory shampoos that contain tea tree oil and tar, recommends Donovan.

If you have red, scaly patches on your scalp, it's likely psoriasis, an autoimmune disease that can be treated with prescription topical cortisone and tar, or salicylic acid–based shampoos.

Get it under control
A flaky scalp is not caused by dry skin. In fact, everyone's scalp harbours the yeast that causes dandruff. In some people, this yeast, known as Malassezia, creates a byproduct that triggers the scalp to overproduce skin cells, leading to itchiness and flakes. If the itchiness is severe, the flakes are thick and yellow, and your scalp is red, you could be suffering from dandruff's more severe cousin, seborrheic dermatitis, says Toronto dermatologist Sonya Cook. Unfortunately, there's no cure for either this or regular dandruff, but you can manage these conditions by lathering up on a regular basis with antifungal products that include ingredients such as pyrithione zinc (found in Head & Shoulders), selenium sulphide (in Selsun Blue) or ketoconazole (in Nizoral).

Apply sun protection – all over
Your scalp can get sunburned just as easily as the rest of your body, and it's just as susceptible to skin cancer, says Dr. Charlene Linzon, a dermatologist in Toronto. You can apply a spray sunscreen to your part (or any visible skin on your scalp). If your hair is thinning, Linzon advises wearing a tightly woven wide-brimmed hat for the best protection.

Beware of overdoing it
If you're blow-drying on a hot setting too close to your scalp, you can bubble the water in the hair shaft and cause temporary damage to the hair follicles, says Linzon. Also, don't fall prey to the old wives' tale about brushing your hair 100 times before bed. Overbrushing does more harm than good, causing breakage and split ends.

Look at your overall health
Hair loss or thinning can happen for many reasons, but it's often an indicator of underlying health issues. Genetics, autoimmune diseases, stress on the body (such as a restrictive diet or extreme weight loss) and having a baby can all result in shedding hair, says Linzon. Head to your doctor to check your iron, thyroid and hormone levels.

For more ways to keep your head comfortable and happy take a peak at our list of best hair products for a healthy scalp. Also, check out our expert advice for basic hair care to find more tips on how to keep your locks radiant.

This story was originally titled "The Root of the Matter" in the June 2013 issue. Subscribe to Canadian Living today and never miss an issue!