Does chronic fatigue syndrome get worse over time?

CFS. It depends. If you change your lifestyle and treat the cause, then you should improve in 1-3 years.
Chronic fatigue. Chronic fatigue can become worse over time but can also be related to age related changes from hormonal decline, vitamin deficiencies or reduction in level or time as well as from the increased degenerative changes in your body. The best strategy is to always eat well, get your hormone levels checked since they can help and take your vitamins.