What is the difference between dandruff and dry scalp?

Dandruff and dry scalp are often mistaken for one another but are two distinct conditions. Dandruff is a chronic scalp condition where the normal skin cell turnover rate fails, caused by a fungus called Malazzesia. It results in skin cells dividing too quickly (every 15 days instead of the more typical 30) for the normal keratinisation or hardening process at the epidermis of the scalp. Skin cells are shed in large clumps, appearing as white or greyish patches on the scalp, skin and clothes. Dry scalp occurs when the scalp loses moisture due to environmental factors like heat, UV damage or lifestyle factors such as over-shampooing. Dry scalp can cause itchiness. It is possible to have dandruff and dry scalp at the same time.