Nancy,
I can only imagine how you feel.
If you would indulge me I would like to take a swing at answering your question about flares?
Understand that rheumatoid arthritis is a complex disease that results and symptoms beyond just painful joints during a flare.
These may include everything above that you have already cited, most commonly it includes:
Fatigue
Fever
Inflammatory nodules under the skin (bumps) increased stiffness in joints
Pain throughout the entire body
Increased difficulty in every day tasks
Swelling of hands and feet as well as all large joints
Flu like symptoms
Etc. etc. etc.
The next question is obvious “triggers“:
Certain foods
Change medication‘s
Any kind of injury
Stress
Lack of sleep
Excessive physical activities
etc. etc. etc.
How long will a flare last?
Six weeks or longer
Morning stiffness that last from 30 minutes to all day
If you’re lucky? It will be less!
What can you do about it?
Medication or combinations there of
Healthy diet😋
Exercise tolerance💃
Mental attitude 🧘🏻
Spiritual balance🙏
Hopeful this may help!

Isn’t that the $64 question.
You may find that everyone here will give a different answer to that question.
As genetic engineer, I can prove to you that every single person that exists on the planet today is totally unique and specifically and wonderfully designed to be only that person they are AND is so unique that they are the ONLY person that has existed for the past 14 billion years as well as the next 14 billion years.
Therefore, when that one variation that causes chronic disease occurs in just one of so many biological systems known as the immune system it’s probably not a surprise that everyone is going to be different in “flares” from chronic disease.
Apologies for such a long answer to such a short question!🌹

I was diagnosed January 2021. I am in pain most days. Waiting on Humira to fully kick in. I have noticed eating sugar makes all my pains much worst. Thank goodness for Keto desserts and sugar free candy. :)

I am not sure how long flares last but am going to make an appointment with the Nurse Practitoner in my Rheumatologists office to find out more about flares, pain management, when to call the doctor, how to report symptoms, exercise, and diet. I have read that sugar aggravates RA symptoms and sometimes you can keep a journal of what you eat and do, so that when you have a change in your discomfort, you may be able to link it to a food or activity

Absolutely sugar causes inflammation which for us with rheumatoid means pain!!!! I definitely have to watch the sugar intake and I do. Doesn't matter I was diagnosed today with type 2 diabetes. Hang in there and stay strong Gavin.