Stress causes physical changes in the body designed to help you take on threats or difficulties. You may notice that your heart pounds, your breathing quickens, your muscles tense and you start to sweat. This is sometimes known as the 'fight or flight' response. Once the threat or difficulty passes, these physical effects usually fade. But if you're constantly stressed, your body stays in a state of high alert and you may develop stress-related symptoms.
 
Symptoms Of Stress
Stress can affect how you feel emotionally, mentally and physically, and also how you behave.
How you may feel emotionally:

overwhelmed
irritable and 'wound up'
anxious or fearful
lacking in self esteem

How you may feel mentally:

racing thoughts
constant worrying
difficulty concentrating
difficulty making decisions

How you may feel physically:

headaches
muscle tension or pain
dizziness
sleep problems
feeling tired all the time
eating too much or too little

How you may behave:

drinking or smoking more
snapping at people
avoiding things or people you are having problems with
Visit the Mind website for more signs of stress.

How To Tackle Stress  
You can't always prevent stress, but there are lots of things you can do to manage stress better. You could:

try these 10 simple stress busters
use these easy time-management techniques
try mindfulness – studies have found that mindfulness can help to reduce stress and improve your mood
use calming breathing exercises
download some relaxation and mindfulness apps onto your phone
listen to an anxiety control audio guide

Other things that may help:

share your problems with family or friends
make more time for your interests and hobbies
take a break or holiday
take some regular exercise and make sure you are eating healthily
make sure you are getting enough sleep (see tips on better sleep)
Read how 'workaholic' Arvind learned to deal with stress.

What causes stress?

Big life changes often create stress, even happy events like having a baby or planning a wedding.
Feeling that you aren't in control of events in your life – for example, if you are diagnosed with a serious illness or you get made redundant – can also cause stress.

Stress may be related to:

work – for example, unemployment, a high workload or retirement (see Beat stress at work)
family – for example, divorce, relationship difficulties or being a carer
housing – for example, moving house or problems with neighbours
personal issues – for example, coping with a serious illness, bereavement or financial problems

It's important to tackle the causes of stress in your life if you can. Avoiding problems rather than facing them can make things worse.
However, it's not always possible to change a stressful situation. You may need to accept there's nothing you can do about it and refocus your energies elsewhere. For example, if you're a carer, find ways to take breaks and do the things you enjoy.
When To See Your GP About Stress  
If you've tried self-help techniques and they aren't working, see your GP. There are lots of other options open to you, such as guided self-help or cognitive behavioural therapy (CBT).
You may be able to attend a stress management course. Ask your GP or self-refer to your local psychological therapies (IAPT) services.