@Aster The thing is, I don’t think an endocrinologist is the right type of doctor if you are truly concerned about the lymph node. I know very very little about diabetes. I assume unsteady sugar levels can contribute to fatigue? We can probably rule out fatigue from thyroid since he sees an endocrinologist. I would assume the endo does basic blood tests/panels like CBC and CMP, so probably the person is not low in iron, or having some sort of red blood oxygen carrying condition that would make them tired. But, this is all assumptions based on what you have told us. Assumptions can be bad as we all know.
Does he also see a regular GP or internist? Or, uses the endo as the main doctor? I use my endo for most tests, GYN for the girly parts. I almost never go to a GP, definitely never for yearly check ups. I am not saying that’s good, just sayin’.
I always suggest testing vitamin D as I think so many people are dificient, and I know so many people who feel stronger physically when they get their levels back in the normal range. I never recommend any megadosing untill the blood tests are done and the patient works with some concrete information. Possibly test for some other nutritional dificiencies. Is he overwieght? Does he exercise? Under a lot of stress?
I had swollen lymoh nodes for about 8 years, this started 20 years ago, doctors could have cared less. But, I did have other signs of infection, I won’t go into them here. My ESR was elevated, but doctors didn’t care about that either. I finally got some treatment, mega antibiotics, and my lymph nodes in most area went back to normal. But, my situation has nothing to do with your friend except that, it is possible to have lymph nodes swollen and tender for years and for it to resolve. I don’t think it is a good thing to be like that, obviously I was sick and I believe it did some damage to me short term and long term, but just communicating what can happen. Plus, it occurs to me diabetics have a tougher time fighting off infection, so his lymph system might work very hard. I’m not sure of the science of how that all works in the body.
I would probably see a rheumatologist, just a gut reaction, if you are very concerned, or just want some answers or to rule some things out. You could see an oncologist if you are very concerned it is cancer, but most oncologists require a referrel, so you would need a docor to say they are suspicious of cancer at minimum I would think? Not sure.