Your mum needs a hysteroscopy
and D and C to find out what is going on. An endometrial thickness of 20mm at your mum's age is not normal. It may be due to endometrial hyperplasia
, that is excessive growth of the endometrium due to possible hormonal
imbalance. In any case, it is very important that the doctor takes a sample from the uterine cavity
and sends it for histopathological examination. Once a diagnosis is established, your doctor will advice you how to proceed further.