Your skin constantly renews itself; dead cells from the scalp fall off as new cells form beneath them. Everyone loses skin cells in this way.
With dandruff the process is faster, so a greater number of cells are shed. This means the cells shed in clumps (flakes) that are big enough to be seen by the eye.
Flakes of dandruff are especially visible when they land on dark clothing. The scalp can also be itchy. The medical name for dandruff is pityriasis capitis, and it's the most common condition of the scalp.
Many people think they get dandruff because their scalp's too dry. They stop washing their hair with shampoo, or wash it less frequently, because they believe it makes the condition worse. This isn't true.
Flaking only happens because of an increased turnover of skin cells or an infection of the scalp. It's more common in children with eczema.
Dandruff is believed to be associated with an overgrowth of a fungus commonly found on the skin and scalp, called Malassezia (previously called Pityrosporum ovale).
Dandruff is one of the most commonly experienced problems relating to the hair and scalp. Probably every single one of us has experienced a dandruff problem at least once in our lives. While the problem is rarely physically painful, dangerous, or even uncomfortable, it does cause a great deal of social discomfort to most people.
For Dandruff, Massage the Scalp with pure coconut oil. This will also help for growth of hair. Apply coconut oil which has been boiled with small onions. Wash it off with a mixture of green gram powder and water drained from cooked (boiled) rice.Apply a mixture of almond oil and gooseberry juice with finger tips on the scalp. Apply the warm mixture of olive oil, lemon juice and coconut oil. Do a steam -towel- wrap for 15 minutes and wash the hair with a shampoos. Apply a paste of fenugreek and mustard to the scalp. Mix Shikakai powder with the |water drained from the cooked rice and wash the hair with it. Crush the leaves of five petal hibiscus flower and take the juice. Wash the hair with this juice. Heat the oil with a little camphor. Apply the oil in the scalp and massage for 10 minutes. After 30 minutes wash the hair with a herbal shampoo. Do the steam -towel- wrap for 15 minutes.
 Natural Dandruff Remedies
Apple cider vinegar - Apple cider vinegar will help restore the proper acid/alkaline balance of the scalp and kill a bacteria that clogs the pores that release oil to the scalp. The clogged pores result in scales and crusts being formed. Apply apple cider vinegar diluted 50% with water to the scalp and let dry. There is no need to rinse. Another similar remedy suggests pouring two tablespoons into a cup, applying the straight vinegar to the scalp, and leaving it on from 15 minutes to three hours before shampooing. Lemon juice may also be used. It is the acid in these remedies that helps bring the scalp back into chemical balance.
Grapefruit seed extract - Mix 7-10 drops with the normal amount of shampoo you use. Massage into your hair and leave on for at least 2 minutes. Rinse thoroughly with water, avoiding contact with eyes.
Listerine For mild cases of dandruff, use the mouthwash Listerine. It has antiseptic properties. Do not use on cases where the skin is broken as the Listerine can be irritating.
 Herbal Remedies
Rosemary Rub rosemary oil or a mixture of olive oil and crushed rosemary leaves into your scalp and leave on for 15 minutes.
Thyme - Make a rinse by boiling four heaping teaspoons of dried thyme in two cups of water for ten minutes; strain and allow to cool. Massage this tea in your clean, damp hair; do not rinse out. The oil from the thyme has antiseptic properties.