Oily Hair is a drag, but dry hair is no picnic, either. Dry hair is dull hair, and it looks the same after you wash it as it did before. Everyone has bad hair days, but with dry hair you may have those days more often than not.
Along with dry hair, you may also have a dandruff problem. Although it’s more often a condition associated with oily hair, people with dry hair get dandruff, too. Common dandruff is simply a layer of skin shedding from your scalp. When the skin cells get trapped on your scalp by your hair and clump together, you have dandruff. And dandruff can make your hair look dull.
Dry hair can result from external factors, such as exposure to harsh chemicals, or from internal causes, such as an illness. These are the primary external factors for those lackluster locks:
Article from: http://health.howstuffworks.com/wellness/natural-medicine/home-remedies/home-remedies-for-dry-hair.htm