Reactional hair loss is the type of hair loss which occurs sometime after certain biological situations. The most common one is the hair loss seen in women four-five months after giving birth.
Similarly, after high fever, a severe physical trauma or stress, the body can give the same reaction. Reactional hair loss/alopecia is often not permanent. It goes on for about one or two months, and the hair starts growing back on their own without any treatment. It is very important to identify the reactional alopecia from male pattern genetic alopecia.