Dad's using profanity against my mom. How can I bring peace back to my home?

I agree that the primary care physician should make a referral to a neurologist, preferably one who specializes in geriatrics. This is not only so that the primary care physician, rather than you, is the one making the referral but also because primary care physicians usually aren't the best trained to diagnose dementia or other neurodegenerative conditions. If the neurologist suspects that your father has cognitive problems, he will probably make a referral to a neuropsychologist for further testing.

Tell the primary care physician that he needs to be seen by a neurologist for proper testing. Tell your Father that his doctor wants him to go to a specialist. Try to make it sound like it is all the primary care physicians idea and he needs to follow the doctors advice to keep his insurance active - or whatever little white lie will get him to the testing. Medication may help but the initial step is a neurologist evaluation. Good luck...

So can they just go to their Primary doctor to get evaluated? Also, any tips on bringing this to my dad delicately that he needs help?

It sounds like the beginnings of dementia when the anger and emotions cannot be held in check. Get him medically evaluated. The cursing will stop only when he is much farther along in his illness. Your mother needs to go with him to the doctor's office so she can provide input.

Has your father been diagnosed with some form of dementia? Unlike Alzheimer's Disease, other forms of dementia often present first as personality changes. It would be a good idea to have him evaluated, if he would agree to that, to see what is going on. My husband, who was diagnosed with Dementia NOS (Not Otherwise Specified) was diagnosed in 2008, at which time he had significant memory problems, However, looking back with hindsight, I can see that the first symptoms he showed, more than 10 years ago, were personality changes. My husband had become very verbally and sometimes even physically abusive to me because he didn't understand that it was necessary for me to supervise him, seeing this as "micromanaging" and "controlling". Since he had been on medication for depression for many years, the doctor added Seroquel, an antipsychotic. This has made a big difference.

Has he changed in other ways? Does he show remorse afterwards? Grumpy and rude seems to get worse as people age. Has your Mother spoken to him in a loving way about it? It is really her position to demand respect. If all else fails, an appointment with doctor to determine what it's all about. Ask him how he is feeling and if he has any worries or concerns he wants to talk about. He may say nothing, but the next time he"acts out" inappropriately, it gives you an opportunity to bring up your own concerns about the details of his behavior. Take care:)