I Experienced A Feeling Like I Was Going To Faint

I experienced a feeling like I was going to faint a few hours ago, just before going to lunch. I had been standing for a few minutes and then experienced a light headed sensation. I wasn't particularly hungry and haven't changed any meds. I have had a very stressful week, having placed my 87 year old mother in an assisted living memory care unit last week. I know this has been weighing on me.