Dandruff is not dangerous however it might turn up very embarrassing in some unavoidable circumstances and is basically an extreme scaling of lifeless skin on the scalp which is more likely white flakes and being careless might lead to hair loss.
Symptoms can range from small and white to large, greasy, and yellow flakes. These can be itchy and form around the hairline, scalp, eyebrows, nose or ears.
Actual causes for this particular skin disorder are still not known but it can be termed as a type of dermatitis. Some of the factors which can actually aggravate the same are overreaction of sebaceous glands and fungus in some people, food allergies, too much sweating, using strong shampoos, yeast infection, stress and can be hereditary.