Stress: one of the most common modern illnesses du jour.

The causal factors creep up from all sides, and it's threatening to overtake depression as the most common mental illness of our times. Some workplaces even take a sort of perverted pride in pressurising their workforce, prizing most highly those workers who can produce no matter how much stress is piled upon them. But is it really good for us?

The common pressures of everyday life can sometimes be stressful enough in their own right, but things have started to get a whole lot worse lately. Jobs are scarce and many of us are fretting about how to pay our mortgages, or the intense competition of the jobs market. “The ability to work well under pressure” is now on all of our job descriptions – even those of us who haven't got a job.

Often, people claim to work better under pressure and yes, a certain amount of stress can be healthy, but too much can leave sufferers feeling anxious, despairing, and unable to function properly. It produces unwanted side-effects, like forgetfulness, inefficiency, irritability, sleeplessness, and physical side-effects like constant headaches, backaches, and nausea.

You are the best judge of how much stress is too much. If you're getting to the point where the sight of your workplace is making you want to turn around and go home again, or the sight of your in-tray makes you want to vomit, it's time to do something about it.

Many employers are making hay from the recession in terms of what they can demand from their employees. Many of us feel powerless to stand up for ourselves in a climate that means many of us fear for our jobs and our position at work. But the recession doesn't give your employee the right to turn you into an automaton. Regardless of the economic climate, you've still got rights, dammit.

In terms of managing stress, particularly that which arises from the workplace, I advocate a two-pronged approach. Firstly, you've got to do what you can practically to improve matters at work; and secondly, you've got to do what you can to look after yourself.

Credit crunch notwithstanding, employers still have responsibilities towards their employees' health and safety, and this includes their mental health. It doesn't matter whether an employee is demanding that construction workers work without wearing hard hats, or that an employee does the work of two people without any support; it contravenes their responsibilities under the act. The only difference where the hazard is to mental health is that it can be slightly harder to gauge the effect on employees.

Again, you are the best judge of your own work situation. If your colleagues are coming into work and spending their entire day with their head down, avoiding eye contact so they can crack on with an arduous workload, it's a good indicator that you're all overworked. Now might be a good idea to gauge the feeling amongst your workmates; gather together to pile the pressure onto your employers to support you to start a staff representative group to air your concerns.

Equally, one of the best things you can do is to join a union. It's against the law for any employer to intimidate its employees out of joining unions or fighting for employment rights and good conditions; if your employer starts to do this, they're breaking the law.

In the workplace, strength is definitely in numbers; if enough of your colleagues are willing to stand up with you, you're onto a winner. If they aren't, it's all you can do to manage your own mental health.

One important factor in avoiding the causes of stress is learning to assert yourself; and to this end, I'll recommend one of the only self-help books I ever recommend (it's a winner) – Assert Yourself: Simple Steps to Getting What You Want by Gael Lindenfield. If you're already struggling with your workload, and your boss wants you to take on more, the best thing you can do is to tell her 'no'. It's hard to do sometimes, particularly as so many of us are accommodating and keen to please, but if you keep on saying 'yes' when already your heart is sinking at the thought of how much you've got to do, the only loser is yourself. And who wants that?

If you're feeling snowed under, looking after your own interests is key, and you mustn't feel guilty about looking after them. Make sure you look after yourself properly, and this means eating well (nuts, seeds, fresh fruit and steamed vegetables) at least once a day, and taking exercise.

When your hours are long and work leaves you feeling drained it can be hard to find the energy to cook and take exercise, but there really is no substitute for it. A recent MIND survey demonstrated that taking exercise in green spaces (ecotherapy) lowers stress levels and improves participants' ability to think properly. Taking an hour to walk around a park or forest two or three times a week – rather than crumpling into the sofa for the night – will raise your energy levels and improve your brain power.

Whatever you do, don't be fooled into thinking that only the weak submit to stress. Any one of us can become a gibbering, ineffective wreck when we're overpowered with an unmanageable workload and poor conditions, whether they come in the form of unsupportive colleagues or poor systems at work. Don't suffer uncomplainingly, and when things come to the crunch, always make sure that you look out for yourself rather than trying to plough on through.