In some cases, chronic fatigue syndrome (CFS) develops after a flu-like illness such as mononucleosis (mono) or after a period of unusual stress. But it may also occur without warning, even if you have not been sick.
The fatigue may come upon you gradually or quite suddenly. Because fatigue can be vague and can be caused by many things, you might not pay attention to the problem for several weeks or months. It is hard to say what is normal with CFS. That's because the diagnosis often is not clear for some time.
- Symptoms are worse at the beginning.
- You may feel better for a time and then feel worse again. Some people have severe fatigue and other symptoms for many years. But many people will feel somewhat better or a lot better over time.
Some people find the fatigue, pain, and thinking problems caused by CFS greatly hamper their lives. But other people are not nearly as affected.
- Most people are still able to do some of their usual activities at home and work, but they often are unusually tired after they do them. People often have to cut down on social and recreational activities to save their energy for work and family.
- Other people have trouble doing most or all of their daily activities, including work and the basic chores of daily living. They may have to carefully plan how to best use their energy.
- People with severe CFS have trouble getting out of bed and need help with basic activities such as dressing, eating, and bathing.