What Causes Persistent Joint Pain, Fatigue And High Blood Pressure?

Question: Both of my daughters are having health issues. Both have recently been to doctors and have found out nothing. One of them seems to have fatique all of the time, can't seem to lose weight (she is not overweight but if she tries to loose a few pounds by eating just meat and vegetables, she can do this for a month and lose maybe 2 pounds and it will come right back with the first piece of bread she eats). She also has aching in her joints. Her dad has fibermyalgia and thyroid problems run in the family, but they did blood tests and her thyroid levels seem to be okay. Her blood levels were high on some items that seemed to point to a possible kidney problem. She was advised to go on a strict meat and potato diet for 30 days and gradually reintroduce food items to see if she is having a problem with a particular food group. This has been an ongoing problem for her with the fatigue and joint pains.
The other daughter's problem is new this week. She woke up with what she thought was a neck cramp. Now the cramp has spread to her back and chest. Also, when she goes to the bathroom, she has a burning in her stomach and her one ovary seems to hurt that she had a tubal pregnancy in once and it lead to a severe infection before it was noticed. I don't know if any of her problems are related, but when she went to the doctor they asked her if she could be pregnant and she said she could because she is not taking a prevention (she has had three miscarriages but still would like another child if possible). She did find out that she has a clotting disorder last year. Anyway, since she wasn't positive about the pregnancy thing (she doesn't really think she is), they couldn't do one test. They were going to check to see if she had a urinary tract infection, but she has had that before and knew that wasn't it.
Any suggestions on either of these? Thanks for any input.

This was actually two questions regarding two different daughters. The first paragraph was about my 27 year old daughter with an on-going problem of fatigue and joint pains continually with a very slow metabolism. The second paragraph was about the second daughter who is 30 years old and her problems are new. She has had the neck, back, chest pains for just a few days. First it started with the neck and now it has spread to the back and chest. It seems like a crick in the neck that has spread. Or it could be from working out. The second daughter is also experiencing burning pain near the ovary where she had the tubal pregnancy when she goes to the bathroom. I doubt these two things are connected in the second daughter. The only reason I wrote is because both have been to the doctor and haven't gotten any answers and I was hoping someone else might think of something.