My Mother Has Been Suffering From Sudden Chemical Smells.She Is

my mother has been suffering from sudden chemical smells.She is a hypertensive patient.She had a high blood pressure episode and had gone to the hospital.After she returned she has been complaining of a chemical smell that comes suddenly and goes away.She is 78 years old.She is diabetic.She has had short term memory loss last two years.Right now her blood pressure is controlled.But the smell episodes are there.Please help.