You’re sensitive to your hair’s natural fungus
Contrary to popular belief, dry skin isn't one of the causes of dandruff. The real culprit: an overgrowth of a common yeast called pityrosporum orbiculare. The yeast feeds on skin oils, which may explain why people with oily scalps are more susceptible to dandruff. “Some people make oil that is particularly likely to harbor this organism, and they get dandruff at the drop of a hat,” explains Robert T. Brodell, MD, professor and chair of the department of dermatology at the University of Mississippi Medical Center. Normally, a mild case of dandruff will respond to self-treatment, so give home remedies (like these 11 natural dandruff treatments) or over-the-counter dandruff shampoos about two weeks to work. Check out these other 21 reasons your scalp might be itchy.
You’re stressed out
Dandruff may be a clue that you need to relax. “Stress can worsen any skin condition,” says New York City-based dermatologist Lotika Singh, MD. Stress impairs your immune system and can be one of the causes of dandruff, provoking flare-ups. “Particularly in the cases where the dandruff is itchy,” she adds. “[Stress] can perpetuate an itch-scratch cycle: the more the patient scratches, the itchier it becomes.” (Don't miss these other 8 scary signs stress is making you sick.) Incorporate relaxation techniques into your everyday routine. Try yoga, a daily walk, or some deep breathing (inhale for a count of four, hold the breath for a count of four, exhale for a count of four).
You’re not shampooing (or rinsing) your hair enough
Proponents of the “no-poo” (no shampoo) movement say frequent washing can strip your hair of necessary oils. But those oils can also create a hotbed for flakes. “Dandruff can result when there’s a build-up of oils/sebum or sweat on the scalp, says Dr. Brodell. “Washing hair more frequently can help reduce the sebum and control dandruff and its symptoms.” Opt for shampoos with tea tree oil, which has been shown in studies to significantly improve the severity of dandruff. (Or try one of these other best shampoos for dandruff.) And take care to rinse shampoo thoroughly: leftover residue could create a feeding ground for pityrosporum orbiculare.
You’re not eating properly
It’s not too surprising that healthy skin and hair come from the inside out. While experts won’t go so far as to blame dandruff on a poor diet, certain foods may cause a flare-up, especially if you’re already prone to dandruff. “Diets high in saturated and trans fats cause your sebaceous glands to produce more oil, which makes dandruff worse,” Beverly Hills dermatologist Stuart H. Kaplan, MD, told EverydayHealth.com. (Here are 8 more signs you eat too much bad fat.) Aim to eat more healthy monounsaturated fatty acids, or MUFAs, whenever possible. Great sources include avocados, nuts, olives, and safflower oil. Too little vitamin B complex, which contains biotin, a nutrient that forms the basis of hair cells, may exacerbate symptoms as well. Load up on vitamin B-rich foods like oatmeal, rice, eggs, and bananas.
You’re over-styling your hair
Using thick pomades or certain oils can potentially worsen dandruff. “Yeast feeds off lipids and can proliferate in their presence,” says Dr. Singh. Cut back on hair sprays, styling gels, and mousses when possible if you think hair products might be one of your causes of dandruff. These styling products can build up on your hair and scalp and cause oiliness. Don't miss these other 12 mistakes that leave your hair unhealthy.