FMLA is the Family Medical Leave Act.
Covered employers must grant an eligible employee up to a total of 12 workweeks of unpaid leave during any 12-month period for one or more of the following reasons:
My wife has Asthma and was encouraged to file FMLA to protect her employment because she many times misses more work than is allowed by her company's policy. Time off for the covered ailment does not have to be consecutive. It can be spread out over the calendar year.
It is the employees responsibility to file and do the "leg work" for FMLA. Usually a family doctor can assist. The employer can not deny FMLA, but they are likely not jumping at the opportunity to assist in getting it started.