I have had to have a sleep study because my iron is extremely low and I was taking the most iron tablets you take they say if you have this you could have stomach cancer so an endoscopy and a colonoscopy lucky no cancer sent me for sleep study.I stop breathing 19 x an hour which is mild but cos I am having surgery I have to use a breathing machine at night and I hate having to use it but they said only until after operation.Then if I don't want to use which I can't wait to give it back.