My mom 53 have very low ferritin and haemoglobin level from past many years and she have lost her apettite from past few months.

LOw iron: Iron is low-Why?: not consuming enough iron, or not absorbing the iron eaten or losing iron. Not absorbing: intestine problem or chronic inflammation. Losing iron: bleeding -most common; from the stomach/intestines/colon (even if you don't see blood) or from excessive menstrual bleeding. Losing appetite -probable chronic inflammation (reasons for this is very long) -speak to the doctor soon