Ghusl On Whole Body But Only Masah On Head
For women, Prophet Muhammad (Sws) gave a relief if theIr hair are plaited, then pouring water over them without disentangling them is enough. Other than that, a person who is well enough to perform Ghusl on the rest of the body, should wash hair as well, unless there is some medical reason or genuine hardship over and above the usual hardship.