… have a full health check

I would never take up the regularly advertised offers by private medical companies to go for a full health check. Why? Well, if you have symptoms, you go to your GP and leave it to them to listen to your history, examine you, request investigations and reach a decision. This process is known as diagnosis. A full health check when you feel totally well is not diagnosis. The procedure is known as "screening". There are few "screening" tests where the advantages of diagnosis and treatment outweigh the disadvantages, and it is likely that your doctor has already checked for these when you first signed on with the practice, or subsequently: for example, in women, a smear test, in middle years a mammography, and for both sexes a blood pressure reading.

One of the samples taken in full screening tests is a blood test for prostate cancer. If you have prostate symptoms, it can be a life‑saving help to diagnosis. If you don't and the screening test shows a high score, it could lead you to have potentially harmful investigations, or indeed cancer treatment, that you may not have needed.

One hears anecdotes about the advantages of health checks. One hears anecdotes about people who have fallen out of sixth-floor windows and lived, but I wouldn't try it myself.

Mike Smith, GP

… go into hospital with dementia

I would avoid going into a general hospital if I had a diagnosis of dementia. People with dementia have difficulty finding their way around hospital buildings. Even the walk from your bed to the toilet and back is fraught with avoidable dangers: shiny floors, bad signage, distracting and disturbing noise, terrible lighting, poor colour contrast between floors and walls, invisible grab rails that blend into the decor, taps that don't look like taps and sinks with no plugs… So you wet yourself, or fall, or get back into the wrong bed, or get shouted at for moving about at all. Then you don't get as much pain relief as other patients with the same condition, and they might forget to feed and water you.

If I had to go, I'd want my family to stay with me as much as possible. Last week, I heard from a woman whose husband has dementia and she was sent off the ward at lunchtime because they had "protected meal times", with no visitors so patients could eat undisturbed. She was trying to stay and make sure he ate. How perverse is that?

Professor June Andrews, director of the Dementia Services Development Centre at the University of Stirling

… have my first child at home

I have experienced many situations where a woman's first labour has not progressed according to plan and, in some cases, become an emergency. For that reason, I would never have my first baby in a setting where there is no immediate trolley access to medical obstetric care, or at home.

Moneli Golara, obstetrician and gynaecologist

… have a prostate cancer test

PSA is a "simple" blood test to check for prostate cancer. Know what it stands for? Prostate Specific Antigen. Or rather, as many doctors will tell you, Persistent Stress and Anxiety.

Prostate cancer is far more common – and, usually, less serious – than most people realise. In elderly men, it's virtually a state of normality. Most of these prostate cancers lie dormant and harmless, and are something men die with, not of. So having a PSA may end up giving you information you would have been better off not knowing. That's if you can trust the result: it's notorious for inaccuracies, with false positives, false negatives and an inability to distinguish between harmless pussycat prostate cancers and the less common aggressive tigers.

Which is why, when men ask for the test, they're potentially opening Pandora's box. We try to guide them through the maze of ifs, buts and maybes. Sure, in theory it could save your life. But in practice it could well lead to worry, unpleasant biopsies and unnecessary, traumatic surgery.

Tony Copperfield, GP and author of Sick Notes

… sunbathe

'If I had been born a doctor, I would never have sunbathed.' Photograph: Getty Images

I wouldn't present a doctor with a list of symptoms. Patients often think this helps their cause, but the sight of a list makes the doctor's heart sink. They're not going to be able to deal with everything in one go and, most importantly of all, it makes them think you haven't got one particular problem, you've got a multiplicity of problems, which is a sure sign of a hypochondriac.

Also, I would never sunbathe or go on a sun bed. I have had skin cancer. People underestimate the risk. They think, "My skin looks all right; how can it be damaged?" Even if your skin doesn't look aged, you can end up with skin damage that sets you up for potential cancers in the future. Sunbathing in your teens and early 20s is a very strong risk factor. We are now seeing cancers like basal cell cancer – which you used to see only on the faces of old weatherbeaten guys who had spent a lifetime outdoors – in the under-40s. We're seeing malignant melanomas, the most aggressive form of skin cancer, in different parts of the body. If I had been born a doctor, I would never have sunbathed. I would go out in the sun, but I would never lie in it with the purpose of getting a tan.

Carol Cooper, GP

… use steroids unnecessarily

Doctors treat a wide range of conditions, but often we don't quite understand the therapies that we're offering, and why or how they work. Twelve years ago, I had colitis. One of the treatments is steroids but, as a doctor, I knew that steroids are one of those treatments we apply to many illnesses without really knowing why they work. We know they're an anti-inflammatory, but all you're doing is masking the problem, and there can be side‑effects in the long term: steroids can make your skin more fragile, they can affect your connective tissue, they can change the shape of your face. It's one thing taking something if you know why it's working, but I wasn't prepared to go down that route. At that point, my lifestyle wasn't great. I was very busy and not eating well. I started eating less sugar, fewer carbohydrates, I stopped eating anything processed. Not only did I get better, but, since then, I've hardly had a cold.

In terms of plastic surgery, I would never advocate long-lasting fillers. People don't want the hassle of coming every four months for injections, but you don't want something that lasts too long in your body, because your body will eventually reject it. It might be an inconvenience to have to come more often, but in the long term it will spare you a bad reaction.

Alex Karidis, cosmetic surgeon

… have a virtual colonoscopy

While I've had a colonoscopy, I'd never have a virtual colonoscopy – a CT scan of the abdomen to find polyps and early cancers in the colon. This is because it's so likely the radiologists would stumble on something else that has nothing to do with colon cancer – small abnormalities on the liver, kidney and lung, things that typically start a cascade of tests, often involving needles into body cavities, even ending in surgery.

I would never take medicines to lower my blood sugar for a haemoglobin A1c of 7%. A long-term study of 50,000 diabetics in the UK found that trying to lower A1cs below 7.5% increases the overall death rate. I'm not sure we should even call an A1c of 7% "diabetes", but I'm very sure I wouldn't take medicines to lower it. Instead, I would try to lose weight and exercise more – and would be open to considering medications to lower blood pressure and cholesterol.

I'd never undergo advanced medical imaging (CT scan, MRI, PET) when I felt well. Studies of total-body CT screening have found 85% of healthy 50-60-year-olds have some abnormal finding, and the average patient has 2.8 abnormalities. That's a lot of follow-up testing and biopsies, and someone can easily be hurt. This has become such a big problem that doctors have a name for it: "incidentaloma". While I'll gladly be scanned if I'm in a car accident or develop acute abdominal pain with vomiting, I'm not getting in a scanner when I'm well.

H Gilbert Welch, professor of medicine at Dartmouth Institute for Health Policy and Clinical Practice, and author of Overdiagnosed: Making People Sick In The Pursuit Of Health

… have an operation I didn't need

Having just had my gallbladder out, and with the complication of leaking bile afterwards, I wouldn't have any operation or procedure without first reading the guidelines for the condition, looking at the complication rates and the risk of doing nothing (ie, how likely the condition is to cause trouble). I would ask the surgeon how many of these procedures he or she carries out a year, and what their complication rate is, Google the surgeon and ask other doctors for opinions.

I would always ask what someone is doing to me and why. If I was in pain, I would ask what they were prescribing me, how much, how often. I would always read my discharge summary from hospital because they are frequently inaccurate. I would suggest trying to stay out of hospital as much as possible and having only tests that doctors will act on. And I would go to a teaching hospital: they are likely to be the safest if anything goes wrong as they will have more experience in terms of volume of patients and expertise of clinical staff.

Luisa Dillner, GP and Guardian columnist

… have my veins stripped

I would never have my veins stripped and would never have a general anaesthetic for it. Not only is stripping very painful, with large scars that have a higher chance of infection; one year later 23% of people have the same vein growing back. After five years 83% do. So it is painful and doesn't even work in the long term. With pin-hole laser methods, we have complete closure of the vein in 97% of people 10 years later. Also, general anaesthetic means you don't move, increasing the risk of DVT [deep-vein thrombosis], plus you can't tell the surgeon it is hurting, so nerves can be damaged – and the damage is found only when you wake up.

If I had liver metastases – when a tumour has gone to the liver – I would not have chemotherapy unless I had been assessed by a liver surgeon first. If the metastases are only in one side of the liver, then removal of this area surgically can cure. The five-year survival following surgical removal of such tumours is far better than chemotherapy.

Mark Whiteley, vascular surgeon

… take sleeping tablets

‘I can’t imagine any situation in which I would start taking sleeping tablets.’ Photograph: Getty Images

I have come across many patients who have been taking sleeping tablets for decades. They are addictive and it can be very difficult for people to wean themselves off them; the side-effects can include falls, confusion, sleepiness in the daytime and the feeling that increasingly higher doses are needed to achieve the same effects. I can't imagine any situation in which I would start using them.

Helen Drew, GP

… follow a low-carb diet

I would never go on a low-carbohydrate, high-protein diet like Atkins, Dukan or Cambridge. Why? Because although you will probably lose weight, they may kill you. Don't take my word for it – read about the 43,396 Swedish women followed for an average of 15 years. Those who stuck to low carbs and high protein had a rising risk of dying from heart attacks and strokes, depending on how strict they were and for how long they endured them. There was a staggering 62% higher risk of such illnesses among the women eating the strictest diet over those who ate normally. Eating is for enjoyment; these diets turn food into medication, and it's patently the wrong medicine – it is often lethal.

Tom Smith, GP

… drink coffee or alcohol in pregnancy

I wouldn't drink coffee if I was pregnant. Coffee increases your metabolic rate and your heart rate, and consequently your baby's heart rate is increased. Coffee and tea also inhibit the absorption of iron. In pregnancy, your iron levels always drop and, while drinking fresh orange juice helps the absorption of iron, coffee and tea do the opposite. The official guidelines say you can drink some coffee, just as they say you can drink some alcohol, but I would never do either. Your baby doesn't need alcohol as a nutrient – it's not something that's going to benefit your child. I know there are the recommendations, but I would never advise drinking at all in pregnancy, especially in the first 12 weeks, when your baby is forming.

Nikki Khan, midwife

… use alternative therapies

I would never use alternative therapies like homeopathy or acupuncture, on the grounds that the evidence for them working isn't strong. And I often wonder whether the valiant efforts we make to keep our terminal-prognosis patients alive make any sense. But I have noticed that often colleagues say the same thing until they or their loved one gets a terminal prognosis, after which they want everything done.

Victor Chua, healthcare practice leader

… have the flu jab

I won't have the flu jab. Elderly patients, or those with a chronic debilitating condition such as heart failure, should consider it, but there is not much evidence that it is of benefit in otherwise healthy young people. Furthermore, the evidence that inoculation of healthcare workers protects patients is very scanty and yet there is massive pressure brought to bear on healthcare workers to be inoculated.

Stephen Leslie, cardiologist and honorary professor, University of Stirling

… have cosmetic surgery

The only thing I wouldn't have is cosmetic surgery. My reason for reluctance? Nothing to do with anaesthesia (safe these days), but entirely to do with surgery, which should never be undertaken for what you might call "soft" reasons. It's not that surgery is so terribly dangerous that I would worry about death. Mainly it's the worry of infection, which can be very unpleasant.

Mark Patrick, consultant anaesthetist, University Hospital of South Manchester

… see a counsellor

I would never see a "counsellor" if I was having mental health problems. Absolutely anyone can claim to be a counsellor – it's an entirely unregulated area. As a result, there's a horrifying variation in the quality, and I have seen too many patients who have been further psychologically damaged by seeing poorly or under-qualified counsellors.

If I were depressed, I'd be very careful to ensure that the therapist I saw had the correct qualifications and was accredited by an organisation like BABCP [British Association For Behavioural & Cognitive Psychotherapies].

If I were paying privately, I'd only ever see a therapist who also works in the NHS or has done in the past, preferably as a chartered psychologist, because this means they have trained to a very high standard.

Max Pemberton, psychiatrist

… refuse vaccinations

'I so often meet parents who are reluctant to vaccinate their children despite the wealth of evidence regarding safety.' Photograph: Getty Images

I would never avoid having my children vaccinated. Several years ago, I volunteered with Médecins Sans Frontières and spent six months in Angola. I'd expected the poverty, but it was the arrival of kids suffering from severe illnesses that should never have occurred – illnesses easily prevented elsewhere, like measles, or tetanus – that saddened me most. That, and the quiet humility with which families would queue for hours under a scorching sun to receive their vaccines.

Now, practising in the west, I so often meet parents who are reluctant to vaccinate their children despite the wealth of evidence regarding safety. Many of these diseases are now on the rise again. And I can't help but wonder if vaccines have become a victim of their own success; that if we, too, had to queue for hours, surrounded by families who'd also been affected by these illnesses – illnesses that can disable and even kill – then we might not take them for granted.

Damien Brown, GP and author of Band-Aid For A Broken Leg: Being A Doctor With No Borders

… dismiss alternative medicine

I would never dismiss an alternative therapy without first understanding how it works. It's taken me years of medical experience to realise that just because a therapy doesn't have evidence behind it doesn't mean it can't help some people. As doctors, we are trained, rightly, to seek scientific evidence of the effectiveness and safety of a given therapy. But conventional modern medicine can't help everyone. Despite a lack of research funding, there is a slowly growing body of evidence of the effectiveness of a range of alternative therapies. A recent example was that yoga can help reduce pain and increase mobility in people with osteoarthritis. Modern medicine remains my own area of expertise, but I now realise other forms of therapy, such as chiropractic and hypnotherapy, can help.

Ian W Campbell, GP

… use homeopathy

I would never use homeopathic medicines. They are based on an 18th-century practice of diluting particular compounds in water or alcohol to the point where the solution is so weak as to contain no trace of the original compound at all. Homeopaths believe that water has a "memory" of the curative substance that then has a beneficial effect. For me, the key word is "believe". Adherents of homeopathy believe in the efficacy of homeopathic medicines in the same way as they may believe in a particular religion. Homeopathy is a faith-based medical system that, in the minds of its faithful, does not require any scientific evidence of effectiveness to be beneficial. If homeopathy is effective, then most of what we have learned in the fields of medicine, chemistry and physics since the 18th century must be incorrect. I find that implausible, so prefer to squander my money in other ways.

Eddie Chaloner, vascular surgeon

… have conventional IVF

I would never have "conventional stimulated IVF", which involves prolonged hormonal medication for three to four weeks, making the ovaries initially menopausal followed by higher doses of stimulation. This method of stimulation is associated with higher risks of ovarian hyperstimulation syndrome (OHSS), which carries serious health risks for women. We can avoid these complications thanks to recent developments in making IVF safer, cheaper, more successful and accessible.

Advances in endocrinology, ultrasound and embryology have made "drug-free IVF" (natural IVF and IVM) more successful and allowed development of safer "mild IVF" protocols requiring fewer drugs in a natural cycle. Why take drugs in higher dosages if you can have a baby with no, or fewer, drugs?

Geeta Nargund, lead consultant for reproductive medicine at St George's Hospital, London

… have a screening mammogram

I won't go for a screening mammogram. Down the microscope, doctors can't always tell the difference between "dangerous" and "OK to leave alone". So it is possible to find things "too early" that are not really life-threatening cancer. The independent review of breast cancer screening published last year in the Lancet helpfully distinguished biases, uncertainties and some bad science. The latest quantification is that of every 10,000 women screened every three years from age 50-70, about 43 fewer will die from breast cancer. Approximately 700 will be given a cancer diagnosis and a whole lot more women will be frightened by being recalled for further tests. Although most women who are told they have cancer by screening are grateful, I wouldn't be sure whether my life was really "saved" or if I'd just become an extra cancer patient.

It appears that for every 15 women who are "screen-diagnosed", three will still die of breast cancer (so screening doesn't save their lives), eight will still live (so screening brought the diagnosis earlier, but treatment would have worked anyway), one will not die of breast cancer (so screening prevents this cause of death) but three extra will become "cancer victims" (so screening leads to having surgery and/or radiotherapy/chemotherapy that wouldn't have happened in her lifetime). Screening can only be credited with one woman not dying of breast cancer, but all 15 have to be treated once something is found. It's complicated enough to understand, and some women will take these odds. But I'm happy to wait until I have symptoms.

Susan Bewley, Professor of Complex Obstetrics, King's College London

… have surgery at the end of my life

I would never undergo major abdominal surgery if I had very little chance of getting off life support afterwards. I have operated on too many people at the end of their lives for emergent reasons, only to see them never get off life support and cause angst among their relatives, who have to decide when to pull the plug. Personally, I would avoid surgery at all costs and try to find another way to deal with whatever problem I was diagnosed with.

Paul Ruggieri, surgeon and author of Confessions Of A Surgeon

These are the personal opinions of individual doctors. Consult your own doctor if you are concerned about your health.