Dr. refuses to test my fiancée for dementia. What can I do?

If his memory loss is due to a lack of oxygen, meds for Alzheimer's will not help him. You could possibly do more for him if you were his wife, but I caution you, someone with dementia cannot enter into a contract of marriage or any other contract.

Who determined that your finacee has "undiagnosed dementia?" While he may have some memory problems, a medical diagnosis is necessary and anecdoctal observation by a fiancee doesn't qualify.

Also, what type of practice does the nurse practitioner work for?

If your finacee has COPD, he should be seeing a pulmonologist, who can test to determine if he has a need for oxygen - you don't mention his use of it so I assume he's not on it.

Medicare has tightened its standards for overnight and/or portable oxygen use, so your pulmonologist would likely do an overnight monitoring study to determine his need for a concentrator for at home use. He/she would also test his SAT rates during an office visit to determine if he should be using portable oxygen when he's out of the house.

You mentioned short term memory loss due to COPD and few other reasons. Have these "reasons" been considered by the nurse practitioner, or by a geriatric or PC doctor?

As his financee, you should insist that he see a geriatric or PC doctor (who can refer to another specialist if appropriate) to get these issues resolved now to determine if are what you suspect and how to treat them. I can't help but think that there's too much nonmedical guessing involved right now and that's not going to solve the issues.

Good luck.

Is this a geriatric medicine doc's office? If not get him in to see one. A neurologist is probably in order. Has he had a CT or MRI of his brain? Some dementia is caused by things that can be taken care of with medication

My mom married a high school boyfriend 7.5 years ago, on her 80th birthday. It has been a long hard road for mom's hubby. He was in complete denial for about 5 years. He thought mom was trying to be funny when she would repeatedly say or ask the same thing over and over again. There are many days I am very concerned about him and his frustration with mom. He certainly never expected my mom's personality would be so impacted. He is not able to provide the necessary care for mom, though he would like to. Think very carefully about your decision.