There has to be exceptions to that law, right?
It is very dependent on your country, state, or jurisdiction. Most places will require a breach of physician-patient confidentiality in the case of violent crimes, rape, child abuse, realistic threats of any of these, that kind of thing. There are also times where we would breach confidentiality but not to law enforcement, such as telling a public health authority like the CDC if you were diagnosed with a notifiable disease. Generally financial crime would not be included in this, but I can't speak for every jurisdiction. Further, some places can require a physician or other healthcare professional to testify against a patient in court; others cannot.
what would you have to gain by telling a doctor or someone that you committed a crime? probably none right? so why do it?
It is often important information in order to make an accurate diagnosis or provide safe treatment. Illegal drug use is the most common. But no, I don't see any reason that you would ever tell your doctor that you are holding large amounts of bitcoin.
so then you do the math. is it worth it to tell your wife some secrets that you own bitcoin?
So if you don't trust your wife to know about your bitcoin, do you trust her to know about your fiat? Do you have secret off shore bank accounts which you skim some of your income in to each month? What about your other assets together - property, cars, etc.? Better keep her name off of everything and make her pay rent to live in your house?