ARIEL LEVE FILE

HABITS: Health-conscious, germophobic

APPETITES: Caffeine addict

EXERCISE: Reluctantly

ATTITUDE: Pessimistic

Can you handle the truth? I can't. I have always expected the worst but have never prepared for it. It is in my nature to worry about illness, but would it be in my nature to cope with it? As Woody Allen said, "I'm not afraid to die, I just don't want to be there when it happens."

My first instinct was to deny: I didn't want to know the bad news. Despite being filled with dread, I couldn't say no to the medical testing for one reason - what self-respecting hypochondriac would turn down the chance to prove: I really am as sick as I think I am?

The only thing that could highlight my Jewish neurotic anxiety more would be to go through this epic journey with a perpetually cheerful, nonchalant British male - Tim Rayment. We would be united on this quest, partners in x-rays and Dexa scans, and there would be someone to pick me up off the floor when I received the ominous results.

Tim's positive attitude was perplexing. Could he really be that blithe about what dangers lurked inside his body? Most men I spoke to expressed an eagerness to know their expiration date. The collective sentiment seemed to be a carefree shrug. Women seemed less inclined to want to have this information, unless they had children.

There are those for whom illness is merely a challenge to overcome. I am not one of those people. I created a mental abacus and began to calculate degrees of tolerance. On the upper deck were autoimmune diseases: multiple sclerosis, lupus, etc, diseases that frighten me the most because they are incurable, and I could not imagine having the strength to persevere mentally or physically should I find out I was afflicted by one. With lupus, for instance, some of the symptoms are poor circulation in the hands and feet, joint pain, and a butterfly rash on the face. A blood test is given to discover if they are related and add up to the disease.

I know this because I have two out of the three symptoms. Six months ago, independent of this article, I was tested. Back then, I did not have lupus. But six months have passed. Just because I was healthy then doesn't mean I am now.

On the lower deck of the abacus: terminal illnesses which, if caught early, could be overcome. Cancer, tumours and the like; these had chances for survival and so I would give it a shot. On the bottom deck, too, were viral infections such as hepatitis and everything else from diabetes to glaucoma.

As I sat on the Tube, wedged between the man in a grey suit doing sudoku and the woman with a tattoo of a leprechaun on her wrist, this divvying up of diseases in categories of despair was my private way of preparing. It was, perversely, reassuring.

At the London Vision Clinic, Professor Dan Reinstein detailed the extraordinary amount of information that can be gleaned from the eye. He could check the optic nerve for transmission of signal. Was the brain working properly? Cranial nerves and brainstem function could be examined through eye movements. There were arteries that could signal vascular disease, and inflammation of cells could gauge the immune status of the body. The eye can even reveal dietary aberrations.

Of course, mine are damaged. All my life I have been seriously short-sighted. Without glasses, I am unable to cross the street. But to my great relief, there were no optical defects. My poor vision is, as Dr Reinstein told me, akin to having bad-quality film in the camera. It could be the retina, or the way the brain interprets the retina. In my case it was neither. It was "not normal and we don't know why".

There are some questions that will remain unanswered. So I wondered: will the rest of this journey confirm my worst fears? By the end I'd have been scanned, poked, drained, injected, investigated, measured, sampled and analysed. I'd be bombarded with magnetic resonances, electrical impulses and have found out I had things called sex hormone binding globulin levels, ageing biomarkers, and hormones labelled TSH. I'd learn my resting energy expenditure was 1,329 calories a day, which indicates a normal metabolism, but my phenotype interpretation, which is how my DNA reacts to drugs, labelled me an intermediate metaboliser. But was I dying?

At the Kronos Centre in Arizona we were handed our patient itineraries - a travelogue of vitals, scans and assessments. I was apprehensive: it would be rare for an exam as all-inclusive as this not to find something wrong. The cardiopulmonary metabolic test seemed to go well. During the treadmill test I was able to exercise for 11 minutes, 1 second. (Before my test I asked how long Tim had lasted. His time?11 minutes.) A spirometry test was performed to show lung function, an H-scan for biological age, a Dexa scan that measured bone mineral density and body fat percentage on the lumbar spine and hip areas.

When I saw the resulting image, I was in shock. My overall body-fat percentage was 20% but the scan made it look more like 80%. I had the scan of a Nordic speed skater on steroids. No one tells you, when you're lying down on a metal tray in a tube, that everything flattens out and spreads. If I'd known that, I would have worn a corset. Suddenly I didn't feel well. I knew the image would be presented standing upright. While these tests and scans were being carried out, vials of our blood and urine were being tested for hormones, trace metals, cholesterol, etc. Soon, it would all be revealed.

But not all tests could be done on site. The waiting room at the imaging centre was eerily quiet. A pimpled teenager in his soccer strip was rubbing his knee, a woman in a cherry-coloured jump suit flipped through a magazine and chewed gum, and an elderly couple whispered questions to each other. Soon we would all be stripped of our rings and clothing, lying still and silent while having mammograms, heart scans, MRIs, or, in my case, all three. It was a room full of vulnerable people who would prefer to be somewhere else.

A brain MRI is loud and claustrophobic but I found it relaxing. I lay back and listened to a ferocious clicking sound that confirmed my brain was being probed from the inside out. This new machine was only in its second week of use; the Ferrari of MRIs. The images would be clearer; the resolution higher.

Unable to wait, I jumped up and charmed my way into the technician's room for a preview. He allowed me to look at an image of my brain on the computer screen. As he explained what some of it meant, I stared, thinking about how every word, every thought, every moral choice and the ability to decide, came from that image.

Dr Antonio Damasio, professor of neuroscience and neurology at the University of Southern California, explained:?"Science is progressing very fast in certain domains, but not so fast in others. So there is a mismatch between what we can diagnose and what we can provide for treatment." For instance, an early diagnosis of a disease such as Alzheimer's, where the treatment has not caught up to the science, would be incredibly damaging psychologically.

A few days passed. Tim and I were called to see Dr William Fulton at Kronos to go over the results. The doctor sat calmly behind his desk, wearing his white lab coat. Our enormous individual binders waited, like the Torah of Wellbeing, to be interpreted. It was our moment of truth. For me, the two areas that mattered most were the areas that yielded abnormal results. There were traces of blood in the urine. This was unusual. Dr Fulton was only doing his job when he answered my next question with frank sincerity. "Tell me," I stammered. "What's the worst-case scenario?"

Nobody likes to hear the word "cancer". Even Tim looked worried. In an effort to make me feel better, Dr Fulton emphasised that my potential for heart disease was far more likely to be a problem than cancer, because my cholesterol levels were very high. This surprised me, since I am a vegetarian who exercises regularly, and for a second I couldn't figure out which was more disturbing: cancer, or a life without cheese and milk.

Dr Fulton explained that it was probably genetic, but I had a hard time focusing on what he was saying because once you hear the word "cancer", it's a long way back to cholesterol. It didn't help that Tim, who eats something called a chip butty, was fine. But then he was presented with a potential heart problem. With both of us now dying, one worry had to take precedence.

I called my GP in New York. In my "I-might-have-cancer" stupor, I left a message, and as I waited for him to call back, phoned my father to share the bad news. But owing to a long history of hearing about my fatal diseases, I had to put Tim on the phone to vouch for the gravity of Dr Fulton's tone. Tim, who had never spoken to my father before in his life, was now conversing with him in a dire manner about bladder cancer, heart disease, and blood in my urine. When the phone was passed back, my father told me a story. He was once informed he might have tuberculosis only to find out later that it was a fingerprint on the x-ray. There are mistakes, he said: medicine is an art. This sentiment was echoed by my doctor, who dismissed that this was anything serious. As soon as I spoke to him, I felt better. The familiar voice of authority protected me from obsessive thoughts. Though they didn't cease entirely, they eased up just enough for me to function.

A week later, I was retested and the results were normal. My doctor, a New York City internist, Dr Robert Samuelson, explained: "The issue is not whether science can tell us things that we don't know, but whether this knowledge can actually prevent disease or prolong the quality of life. For example, while a CAT scan might disclose a tiny nodule or shadow somewhere in the body, the overwhelming majority of these nodules are benign. But once found, they cannot be ignored; they have to be followed up and possibly biopsied and removed. It takes a lot of unnecessary worrying and invasive procedures to learn that your spot was benign! Additionally, it's never been proven that removing tiny early cancers in the lung, for example, actually saves lives. The cancers that kill are probably not these tiny cancers that we can detect early."

Moreover, a lot of tests, he said, are interpreted out of context of the whole being. An isolated lab value may appear abnormal, but when it's evaluated along with everything else we know about someone's health and lifestyle, the value is no longer abnormal. His perspective was in contrast to the Kronos philosophy, in that tests are worthwhile if they are highly specific for diagnosing a disorder, and if there is a safe, effective way for treating the disorder. But in some cases, such as mine, they merely provoke a lot of needless anxiety.

According to a 1998 report published in the Journal of the American Medical Association, over 100,000 Americans die every year from adverse drug reactions - a higher figure than those who die in car accidents. Genelex, a Seattle-based company, offers DNA tests, one of which can determine how the liver metabolises and processes prescribed medications. When given to a physician, this profile can prevent future catastrophes by lowering the incidence of an adverse reaction.

Each person falls into one of the four categories for each of the pathways tested. There are ultra-extensive, extensive, intermediate and poor metabolisers. I am intermediate. I metabolise medicine slowly and will need a lower dosage, as they build up in my system. Had it turned out I was an ultra-extensive metaboliser, I would be in terrible pain after surgery because the painkillers would have little or no effect.

One area of testing where I had no anxiety was the psychometrics. Maybe because there is nothing about my mental health and ability to function that could astonish me. At the Psychometrics Centre we were given a set of tests to determine our ability to function in the workplace. What stood out were my strengths: creative, insightful, careful and sensible when carrying out tasks, effective and confident when it comes to hard work. It also determined my weaknesses: no discipline, suspicious of the intentions of others, may ignore the advice of those who know better. Of course, I'm not sure I agree with the experts on that.

Nearing the end of this journey, I was forced to overcome my trepidation at tackling a psychological, rather than physiological, reality. At 38, was I ready to take responsibility for having procrastinated procreation? The Fertell female fertility test measures the ovarian reserve. It is an easy test with immediate results and has proven to be over 95% accurate. As it turns out, my ovarian reserve was normal. Great. I was fertile with no one to share my fertility with.

So in the end, what did it all add up to? I am healthy. And when I thought I might not be, my reaction surprised me. Because, after the initial shock, my immediate impulse was to want to know more. I did not fall into a sinkhole of inertia; denial was no longer an option. Science has told me something unscientific. That panic is about helplessness, and with information comes a sense of control. I'm grateful there is nothing wrong, but aware that this respite is fragile and temporary. Despite all this I remain, where health is concerned, as vigilant as ever. Only now, when I have dry eyes or bleeding gums and assume that it's indicative of something fatal, instead of avoiding it, I'll want to know.