I am noticing deep ridges on my fingernails. Is this a symptom of something? I am a 65 year old female.

Hard . Hard to tell without a picture. Depends a bit on the orientation of the ridges (vertical vs. Horizontal). Vertical ridging running the length of the nail is common (genetically) and also typically a normal sign of aging, whereas horizontal ridging is caused by other factors. I would recommend you see a dermatologist for further evaluation. I hope that helps.