While many hair issues such as graying, thinning, or balding can be caused by your genetic makeup and are out of our control, thankfully dandruff isn't one of them. This flaky skin on your scalp is the result of malassezia [1], a yeast-like fungus that happens to be found on the scalps of many healthy individuals. Dandruff [2] happens when these yeasty beasties multiply out of control. They irritate your scalp and cause skin cells to die so they flake off your scalp, making your head itch, and making it impossible for you to wear your favorite black shirt.

Some people's scalps may be susceptible to dandruff from lack of washing, illness, stress, hormonal fluctuations, or extra sensitivity to this fungus. Whatever the cause, the good news is that this embarrassing problem isn't something you have to live with. To find out how to control dandruff .

• Since the malassezia fungus feeds on the oils produced by your hair follicles, try washing your hair more often to decrease the oily build-up. If there isn't enough oil to eat, then the yeast can't multiply.
• Shampoo with an over the counter anti-dandruff shampoo such as Head and Shoulders. Make sure to leave this shampoo on for at least five minutes so the active ingredient, zinc pyrithione, can do its job. Use this shampoo every day until your dandruff is controlled, and then you can cut back to a couple times a week.
• Avoid using styling products, or cut down on your use. These just add to the oily build-up.
• Your diet can affect your hair and scalp health too, so be sure to consume foods that contain zinc, omega-3s [3], and B vitamins [4].
• Take advantage of the sunshine this Summer because a little exposure can help prevent dandruff. Of course, make sure to lube up with sunscreen [5] to protect your skin.

Source [6]