Some common scalp and hair disorders are dandruff (seborrhoeic dermatitis), scalp psoriasis infections (fungal, bacterial), infestations (eg. head lice), scarring disorders, trauma from habitual scratching, pulling of hair, grey hair(premature) and genetic hair disorders. Treatment type and duration depends entirely on the underlying disorder. After a thorough history and examination, the doctor will run a few lab tests. Depending on the results, a personalized treatment regime will be recommended.