But a low mood will tend to lift after a few days or weeks.
Making some small changes in your life, such as resolving a difficult situation, talking about your problems or getting more sleep, can usually improve your mood.
A low mood that doesn't go away can be a sign of depression.
Symptoms of depression can include the following:
low mood lasting two weeks or more
not getting any enjoyment out of life
feeling hopeless
feeling tired or lacking energy
not being able to concentrate on everyday things like reading the paper or watching television
Check your mood using this simple questionnaire and get advice on what might help.
When to get help for low mood or depression Whatever the cause, if negative feelings don't go away, are too much for you to cope with, or are stopping you from carrying on with your normal life, you may need to make some changes and get some extra support. If you're still feeling down after a couple of weeks, talk to your GP or call NHS 111. Your GP can discuss your symptoms with you and make a diagnosis.
What types of help are available? If you're diagnosed with depression, your GP will discuss all of the available treatment options with you, including self-help, talking therapies and antidepressants.
Self-help Whether you have depression or just find yourself feeling down for a while, it could be worth trying some self-help techniques.
If your GP has prescribed antidepressants, it's important that you carry on taking them.
Talking therapies There are lots of different types of talking therapies available. To help you decide which one would most suit you, talk to your GP or read about the different types of talking therapies.