Leaves of absence (see also Benefits, leaves)
A leave of absence can be granted or taken for a variety of reasons. Health-related issues are common. However, a leave can also be used as a placeholder, a way to save your space in an institution while you are trying out another one. Some faculty take leaves of several years to work in government service or in NGOs related to their field. Each institution has limits on such leaves, so investigate this before you commit. Unpaid leaves can also be taken when one has won a fellowship at a time other than a regularly scheduled sabbatical, or just as a refresher after a windfall.