Your hair itself can stand being washed just fine and doesn't cause irritation; it can only feel dry and stiff if washed too often. However, your scalp reacts strongly to frequent washing and bad shampoos.
Like the rest of your body, the scalp is protected by a thin layer of sebum. This sebum protects your scalp from drying out and keeps it hydrated. Washing too often removes this sebum layer from your scalp and your scalp is no longer protected. This along with the drying effect of the shampoo causes your scalp to become too dry.
A dry scalp causes dandruff, which is really nothing more than flaking of your scalp. In addition to dandruff, the scalp becomes sensitive and irritations develop. This combined with bad hair products and frequent washing, at some point it's the end of the line and you just can't get rid of that irritated scalp.
How often should I wash my hair?
Every two days is the answer to this. Wash your hair every two days with a good quality shampoo and you will see that irritations and dandruff disappear. Most shampoos that you can get at the local supermarket do little more than degrease and make your hair smell nice, so leave these products aside and switch to a good shampoo. These shampoos are often slightly more expensive than a regular shampoo, but with these you don't have to wash your hair as often and they take care of your scalp. Below is our selection from American Crew and Uppercut Deluxe of good shampoos:
Taking care of hair after washing
Your hair can feel dry and stiff after washing, try using a conditioner or a good hair oil after washing as well. These nourish your hair and scalp and keep them in good condition.
Washing hair if you have dandruff
If you are currently suffering from dandruff, leave that anti-dandruff shampoo aside. Get a good shampoo and wash your hair no more often than twice a week. I guarantee that your dandruff will be significantly reduced and your scalp will feel healthy again. After all, dandruff is a result of a scalp that is too dry. By reducing the frequency of washing, your scalp has time to recover and provide your skin with that all-important protective sebum layer.