You can eat well, exercise regularly, and look the picture of health — but that doesn’t necessarily mean everything is working as it should beneath the surface.
In fact, according to a recent UK Biobank Cohort study, 1 in 15 people within a ‘normal’ BMI are living with undiagnosed cardiovascular disease or high-risk metabolic phenotypes.
Another found that more than half of people with a normal BMI also had at least one metabolic abnormality, despite being within the supposedly idealweight range.
Basically, you can’t judge a book by its cover when it comes to health, which is why regular check-ups are so important in early diagnosis.
Here are the signs to look out for that suggest all may not be as it seems on the outside.
Your blood pressure is high
‘I regularly see people who are surprised when they are told their blood pressure is high because they exercise, eat reasonably well, have a healthy BMI and feel perfectly normal,’ Dr Suzanne Wylie, GP and medical adviser for IQdoctor, tells Metro.
‘But blood pressure is not something you can reliably judge from appearance or how you feel.’
While the NHS notes that high blood pressure often causes no symptoms, over time, untreated hypertension can increase the risk of heart disease, stroke, heart failure and kidney disease.
That’s why regularly checking is vital, even if you feel just fine.
Your cholesterol is raised
You might associate high cholesterol with an unhealthy diet or being overweight, but neither your appearance nor your fitness level can tell you what your cholesterol levels are doing.
‘Cholesterol is something we measure rather than something we can identify reliably from how someone looks or feels,’ says Dr Wylie.
In particular, raised LDL cholesterol can contribute to fatty deposits building up in the arteries, increasing cardiovascular risk.
Dr Wylie adds: ”There are also people with genetically high cholesterol who can be relatively young and outwardly very healthy, which is why I would not regard body weight as a substitute for checking cholesterol, particularly if there is a family history of heart attacks or cardiovascular disease at a younger age.’
You’re constantly exhausted
Although Dr Wylie stresses that fatigue is ‘not specific enough to diagnose anything on its own’, she highlights ongoing exhaustion can be a warning sign for all sorts of issues, from poor sleep and stress to anaemia and thyroid problems.
She explains: ‘If tiredness is persistent, disproportionate to the amount of activity someone is doing or accompanied by symptoms such as increased thirst, passing urine more frequently, breathlessness or changes in weight, it’s worth discussing with a GP.
‘Sometimes, it’s because the body is signalling a problem before there’s anything visibly wrong.’
You get breathless more easily than you used to
Being a little out of breath after running for a bus is normal, but a noticeable change in how easily you manage everyday activity could be concerning.
Dr Wylie says that while there are a number of explanations for a reduction in exercise tolerance, it can sometimes be an early sign of a cardiovascular or respiratory problem.
As such, if you suddenly find yourself struggling with stairs or a walk that you previously managed comfortably — particularly alongside chest discomfort, palpitations, dizziness or swollen ankles — it shouldn’t automatically be put down to getting older or being out of shape.
Your sleep is consistently poor
Loud snoring, repeated waking, morning headaches and feeling groggy despite apparently getting enough sleep can sometimes point towards obstructive sleep apnoea, where breathing repeatedly stops and starts during sleep.
Do you feel regular health check-ups are necessary even if you look fine?
As Dr Wylie explains, this condition can occur in people of any weight, and ‘have wider effects on health, including its relationship with blood pressure and cardiovascular risk.’
So, regardless of whether you fit the ‘stereotypical image’ of sleep apnoea, if someone has noticed pauses in your breathing at night or you’re excessively sleepy during the day despite a full night’s sleep, it’s worth discussing with your GP.
You’re suddenly much thirstier or peeing more
Changes in how often you need the toilet can be easy to dismiss, particularly if they’re gradual. But repeatedly waking during the night to urinate or becoming much thirstier than usual can sometimes point to diabetes or kidney disease.
Again, Dr Wylie stresses that these symptoms ‘are not diagnostic and there are many less serious explanations,’ says Dr Wylie.
However, she adds: ‘Early kidney disease is especially important here because it can be remarkably quiet; the NHS notes that many people with chronic kidney disease have no symptoms in its early stages and that it is often discovered through routine blood or urine testing rather than because the person feels unwell.’
Your resting heart rate has changed
Your heart rate naturally varies depending on exercise, stress, caffeine, illness and medication, so one unusually high reading isn’t necessarily cause for concern.
However, repeatedly noticing that your resting pulse is faster than usual — particularly when you’re relaxed — is something worth mentioning to a GP, as it can be a signal of abnormal heart rhythm, anaemia or thyroid problems.
Dr Wylie advises: ‘If someone repeatedly finds that their resting pulse is unusually fast, particularly when they are otherwise relaxed, or they experience frequent palpitations, dizziness, fainting or breathlessness, it is sensible to have it assessed.’
Your family history tells a different story
Finally, one of the biggest things you can’t see in the mirror is your genetics.
‘Someone can do everything they are supposed to do, maintain a healthy weight and exercise regularly and still inherit a higher susceptibility to cardiovascular disease, high cholesterol, diabetes or other conditions,’ says Dr Wylie.
‘A close relative developing cardiovascular disease unusually early, for example, is something I would want to know about when assessing somebody’s overall risk, because it can change how we interpret otherwise reassuring numbers.’
Essentially, while looks can be deceiving, as long as you keep your GP abreast of family history, get any concerning symptoms looked at, and attend your scheduled screenings, you’re on the right track.
And if you need some extra reassurance and are aged 40 to 74 without certain existing conditions, you can get an NHS Health Check (covering cardiovascular disease, diabetes, kidney disease and stroke risk, as well as blood pressure, cholesterol, waist circumference) totally free.
Do you have a story you’d like to share? Get in touch by emailing MetroLifestyleTeam@metro.co.uk


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