Whenever i put water on my scalp, after 3-4mins my scalp strts to produce so much sebum. it happens after every wash. scalp is painful. what is it?

Boars hair brush: Hot water, styling products (i.e. gels) & using your fingernails when shampooing can contribute to excessive sebum & an oily scalp. You should brush your hair with a boars hair brush - scalp to tip - prior to shampooing. Use warm - not hot - water. Use a clarifying shampoo (or a solution of 1/4 cup vinegar in 2 cups water on your wet hair for a few minutes prior to shampooing). Hope that helps.