Many people have misconceptions about what dandruff really is. Dandruff is simply dead skin from your head which can be shed at different rates with different people at various times in their lives. It can cause social problem as there is an association with being unclean however this is a misconception.
An itchy scalp can be a sign of heavy dandruff. It is totally normal for skin cells to die and fall off so most people have a little dandruff whether they know it or not.
Certain people can have large amount of dandruff flaking along with very a itchy red scalp. This can normal be easily treated with special shampoo.