Life can be stressful. There's no point denying it - although many try to. But there's no pride to be taken in pretending to be impervious to stress, and burying it deep inside can have profound and serious long-term implications for physical and mental health, adversely affecting both careers and everyday life. Some may be more susceptible to the impact of stress than others, but every one of us is susceptible to an extent, every one of us is capable of being harmed by stress that isn't dealt with; what's more, none of us will know just how much harm it might be causing us until it's too late. It's no use just assuming that you won't suffer because you haven't before, or because you see yourself as 'stronger' (although strength actually has nothing to do with it) - it can easily creep up on you without you noticing.

The solution is to deal with stress when it happens, so that once it's over it really is over, done with, finished, no longer able to have an impact on any part of your business or personal life. But before we can look at how best to do this, we need to ask: just what is stress?

Stress is our body's way of getting us out of a tight spot. It's not predicated by what's gone before or what's likely to come, but is just a reaction to an event. Forcing yourself to keep going through a difficult work or family situation is indeed stressful, in that the extra energy to get you through comes from that physical reaction. Fighting or running from an assailant is stress, the body automatically giving that little bit more energy to handle the situation. And in business, stress isn't necessarily a bad thing: if you're standing your ground in a complex negotiation, if you're racing to get a vital piece of work through before the deadline, the extra energy, the boost you get to stand taller and work quicker, that's stress. Stress is an essential reaction, and one that can be used to your advantage in some circumstances - but the physical results still need to be dealt with, still have just as much of an impact.

After all, the stress reaction is an entirely natural one, it's automatic, it comes from within and we can't turn it on and off at will. Because of this, the body's approach - and the longer term impacts - of a positive stressful situation are just the same as for a shock or danger, or for persistent struggle. The heart beats faster, sending more blood and oxygen to the muscles and the brain. The muscles themselves tense. Blood pressure will rise. Breathing becomes more rapid. A lot of the time, we won't notice these changes as we're caught up in the moment, but we may notice their consequences: headaches, chest pains, light-headedness, cramps, tiredness, insomnia, appetite changes, heartburn - how it feels will vary from one person to the next, and we'll often fail to associate the discomfort with the stress that caused it. But if there are physical changes to our body that are causing that discomfort, it's not hard to see how they might stack up over a period of time to create real and lasting harm.

All of which can be a little frightening, so we need to look at what can be done to manage stress and minimise its negative effects, and particularly to counteract the longer-term impact. The vital first step is to identify which aspects of your work are the ones actually creating stress: it does us no good, although it is very easy, to simply say 'I have a stressful job'; we need to find where the stress is coming from, whether positive (such as negotiations or meeting deadlines) or negative (giving bad news to colleagues, perhaps, or dealing with difficult individuals), so that we can deal with it on its own terms.

Knowing what we're dealing with allows us to address it. Managing time is an essential part of this process. Have you any control at what time you'll be facing stressful tasks? Some of us are at our best first thing in the morning, others later on, and there's nothing wrong with trying to focus the most difficult times on those hours when we're most able to handle them. If you have a number of stressful tasks, try to spread them out, so you've time to recover, to do something more straightforward (or go on a break).

And even if the schedule is not something we can influence, we can manage our personal time - we can ensure we always have time to switch off, time away from work that's completely away from work; if your job requires you to take some of it home with you, then fix into your schedule a time when you won't be doing it and stick to that schedule religiously.

It's also important to manage your sleep patterns, so that the stress isn't exacerbated by fatigue: as far as is possible, aim to go to bed and wake up at the same time each day. It might take a little while, but your body will adapt to the times you're setting for it, always getting tired at the appointed time, and allowing you to feel fully awake at the right hour next day. And fix exercise into your schedule too - the chemicals that the body produces under stress need to be used up, and regular exercise (any kind of physical activity, it doesn't have to be competitive, sporting, social or costly) does just that.

It's also important, if others are piling more work onto your shoulders than you can bear, to try to say 'no'. It's not always easy, but standing up for yourself - and having confidence in your reason for doing so - can often play a key role in ensuring both that your workload is manageable and that you're able to handle and recover from stressful situations.

There's one other piece of advice I must pass on, which I can't emphasise enough: there's no shame in stress. It's okay to talk about it, to tell colleagues or senior managers that you're having difficulty coping with the stress of work - remember, it's a medical issue, and not something that simply turns on and off, and we all have a right to expect that work will not injure our health. It's also okay to seek assistance with managing stress - you might want to consider a short training course, for help with learning how to use stress to your advantage while minimising its harm.

And finally, essentially, it's always okay simply to book an appointment with your doctor. Stress is a powerful thing that you can control if you're aware of it - and which can control you if you're not.