No. It is not a progressive disease and it is never fatal. See the excellent information on the www. Arthritis. Org website.
It can.? whether fibromyalgia can "get worse". It can, as cases of those who are bed or housebound demonstrate. Amongst fibromyalgics are all varieties of disability; evidence that the disorder is etiologically variant. Aquatherapy, Cannabis & certain FDA meds proven helpful. Positive activities, nutrition, gentle exercise & mindfulness therapies seem to be integral to healing; as survivors inform us.
Can happen. Several medical conditions can become worse premenstrually.