Fatigue (tiredness) is probably the most common side effect of breast cancer treatment. It's a feeling of having no energy so it's difficult to do simple, everyday things. Rest doesn't make it better. Fatigue can affect the way you think and feel. Even things you usually enjoy doing, like reading or watching TV, can be difficult. It can affect your relationships and make you impatient with people around you. You may avoid socialising because it's too much effort.

It's not unusual for fatigue to last for months after treatment is over. Occasionally, in some people, it may last for a year or two after their treatment has ended. Some women taking hormonal therapies, which are given for several years, find that tiredness is an ongoing problem for them.

There are ways of coping with fatigue and some causes of fatigue can be treated.

Our section on coping with fatigue has more information about what may cause fatigue and ways of coping with it.