Student debt is at the forefront of most students' minds. Every student knows the joy of trying to persuade the bank manager to increase his or her overdraft limit. My housemates and I are no exception.

A few weeks ago I found myself talking to my bank manager. He tried to be sympathetic, but I'm trying to increase my limit for the umpteenth time. Finally, we got round to the inevitable question, "How exactly do you plan to bring your overdraft back down to a manageable limit?" I stuttered a bit, and made a few excuses, but after putting the phone down I thought, "How am I going to pay this back?" I tend to view the overdraft as free money, but living at the limit of your overdraft is beginning to get dull. So how could I make money quickly, and with relatively little effort on my part?

This is when we started to discuss taking part in research experiments. One of my housemates had already been involved with a major company. At a quick glance, it seemed to be a good deal - you get large sums of money for little or no work. I applied to one of the companies, but unfortunately they don't have many opportunities for girls. Apparently drug companies would rather test on healthy males. I resigned myself to living on the breadline once more.

However, when we spotted a notice in the hospital calling for research volunteers I found myself thinking about it seriously. I told my housemate - he jumped at the chance and we rang the number given. The study was looking into asthma and various related things: £100 for a peak flow test and a blood test. Nothing serious I thought - where's the catch? "Oh, and we'll need to do a bronchoscopy as well," the doctor in charge of the study calmly added. Ah - there's the catch. My housemate had no problem with this, and promptly booked himself in for the following week. I told them I'd think about it for a while.

Everyone I spoke to told me not to do it. My clinical partner was horrified. "Do you have any idea what that entails?" she demanded. "It's horrible, you'll feel terrible, and it won't be worth £100 no matter how broke you are." I tried to protest, to convince her that it wouldn't be that bad (or was it me I was trying to convince?) but she remained firm. "Do it if you want, but I think you're being stupid." Her last words were, "You'll regret it."

"How did it go?" I asked my housemate uncertainly when he came back. "Absolutely fine - the sedative they give you - just like having a pint to relax you." Looking back I'm not sure how I failed to see the flashing neon sign above his head with "I'm saying this to appear macho" written on it. I decided to take the plunge anyway and phoned to say that I was willing to take part. I agreed to be at the department on the following Friday morning.

On Friday morning I spent about an hour doing various breathing tests - peak flow, testing the responsiveness of my airways. It all seemed fairly easy and I was confident that I'd be walking away with my £100 with nothing more than a sore throat to show for it. So on Monday morning at 7 45 am I arrived for the bronchoscopy. A nurse approached me to lead me to the changing rooms. "Just slip this on dear," she said, handing me a surgical gown. She must have seen the look on my face as she reassured me, "It's only in case of splashes."

I think I'll say very little about the actual procedure. Needless to say it's not the most pleasant of things, and my compassion for patients undergoing the procedure will know no bounds after this. I don't really remember much apart from flashing lights and voices. Don't get me wrong, the procedure itself was probably perfectly normal, just not what I expected. Oh, and the "one pint" sedative that my housemate described left me staggering around as if I'd had 12 pints, not what I'd call a swift half to calm my nerves. I suffered a nasty sore throat and nose for a couple of days and the sedative left me feeling groggy and tearful.

So was it worth the money? Would I do it again? Well, in a word, no. At least not another invasive procedure. However, I'm sure that I'll change my mind when the cheque goes into the bank. I can see the value of the research, but next time I think I'll leave it to someone else to be a hero for medical science. But hey, I can always exploit the whole adventure by writing about it for the studentBMJ. I hear it pays quite well. What was that about earning money for relatively little effort on my part?