Amaon Won't stop Drinking

I have a 15 year old Double Yellow Green Amazon that has been drinking and urinating way too much to be normal, she did this about a year ago for a week or so and stopped, well It's BACK!!, Anyone have any thoughts or simular behavior?
Thanks
Gary

I don't know how it works in parrots, but for a human, that would be a red flag for Type 2 Diabetes. What is her diet like? Is she overweight?

I consider this but, She's not over weight at all, her diet, has not changed for the past 15 years, and the drinking has come and gone before.
Thanks

Treating Diabetes in Birds: Causes, Symptoms and Conventional & Holistic Treatment Options as well as Prevention

Parrots can drink excessive amounts of water for many reasons. Diabetes, liver disease, kidney disease, lack of humidity, salty foods, behavioral abnormality, etc. Diabetes in birds usually occurs in females and can be related to reproductive activity or disorders of the reproductive tract. The best thing to do is to take your parrot to your avian veterinarian for a physical exam and work-up. The work-up may include blood tests, X-rays, cultures of the chloaca and choana, etc. The color, consistency, and size of the droppings can aid in a diagnosis. Have a description of your bird's diet (everything he eats) and a description of his environment (how big is the cage?, what type of cage?, are there other birds or animals around?, where does he sit in the room?, etc..). Birds can hide their illnesses very well. If a bird is showing that he is sick, the condition can be already quite severe. This is potentially a serious problem or not but I would not want to guess.

I have to agree, it could be disease or illness related such as a kidney or urinary tract problem, a vet check would be highly suggested.

Also, agree re vet if at all possible. The fact that the bird has had these symptoms in the past and recovered doesn't guarantee that outcome each time. If you have access to an Avian vet, I would try to get the bird in and take fresh droppings with you.