What causes dandruff is often a question that can bring about many different answers. People will often throw about things such as poor hygiene, not washing your hair, bad grooming habits, skin conditions, oily scalp and so on. However whilst there is a range of answers to such a broad question, it is generally agreed on that dry skin is the major leading cause of dandruff. If you have a dry scalp then it may become flaky and itchy. As a result of this you may then begin to notice dandruff in your hair. Generally, if you can avoid a dry scalp, you should be able to avoid dandruff.
If you have developed dandruff it is best to first try some simple methods such as using popular anti dandruff shampoos and using conditioner regularly to keep your scalp moisturised. If this does not work then trying a stronger shampoo containing ketoconazole (an anti fungal agent which is effective at fighting dandruff) should generally help clear up dandruff. As basic as it may sound, it is also very important to follow the shampoo instructions. This obviously varies depending on what product you are using, and of course it is very simple! Something as silly as rinsing your shampoo out of your hair too early could actually be hampering your fight against dandruff. There is no need to complicate the process of removing dandruff. For the majority of people, just following these simple steps above should really help to get rid of dandruff.
If after 2-4 weeks you are still not seeing any improvement, I would advise consulting a doctor. There is so many tips, tricks and remedies that you will find on the internet. A heap of wasted time and research (and possibly money) can often be saved by one trip to the doctor. Doctors can prescribe strong shampoos that are specifically targeted at getting to the cause of your dandruff and eliminating it. Sometimes, as good as they are for some people, over the counter shampoos may just not be working. For most people, dandruff should just be a minor issue that can be cured quite easily by taking simple and preventative steps to keep that dry and itchy scalp away.