She can be terminated if she may pass out at out work, and the evidence of passing out twice in a month suggests this is a risk. Her passing out at work does expose the employer to liability if she hurts herself when falling/passing out, or somehow hurts another (e.g. falls into or on them), or potentially causes damage (e.g. knocks over a computer and breaks out; knocks over something else electrical and starts a fire, etc.). She can't be terminated for simply having a condition, but if she has passed out at work (which your question implies), she can terminated for what actually happens and the risks (incuding liability) it imposes on the employer. You say that the medical issue "is in the process of being taken care of," not that it has already been resolved: if there still a risk of her passing out at work, they may take action. If the employer is large enough to be covered by FMLA (at least 50 employees withing a 75-mile radius) and your wife is eligible for it (worked there at least one year; worked at least 1,250 hours in the past 12 months) and particularly if you believe that you may have the issue resolved within 12 weeks (and be able to provide doctor or medical evidence of its resolution), you and she may wish to consider her using FMLA leave during her treatment. She may not be terminated while on FMLA leave or for having used it. So if she can resolve the situation within around 3 months and can use FMLA, this may be an option.