Worried about your thyroid? Here’s the simple £10 DIY test that could reveal the truth… and whether these testing kits can really diagnose you with menopause or cancer at home

You can now investigate your health worries from the comfort of your own home, using DIY testing kits that claim to screen for a range of conditions including high cholesterol, diabetes and thyroid issues. But how reliable are they?

Last month, the Advertising Standards Authority banned online adverts from two companies which claimed their prostate-specific antigen (PSA) test kits could diagnose prostate cancer. It ruled one of the ads ‘misleadingly implied the tests could diagnose cancer and failed to make their limitations clear’.

Here, ADRIAN MONTI asks experts to assess different home-testing kits. We then rated them.

Liver function

Cost: From £7

Rapid liver function tests claim to identify biomarkers such as nitrates, glucose and white blood cells in urine which can be signs of liver damage. You dip a test strip into a urine sample and after about a minute, it changes colour – you compare this with an accompanying chart for a diagnosis.

Expert verdict: ‘Blood tests and scans are used to diagnose liver disease – urine samples are not useful in this context,’ says Professor Stephen Ryder, a consultant hepatologist at Nottingham Hospitals NHS Trust.

‘That’s because if something injures liver cells, they are usually quickly repaired and replaced – so there are no early symptoms or abnormal changes detectable in urine. A urine test would only be abnormal in someone with severe liver disease – and we wouldn’t be using a home test or the ones you take yourself and send to a laboratory for these patients.

‘These kits could give people false reassurance and using a colour chart, there’s also the chance of making an incorrect reading. A complete waste of money.’

Verdict: THUMBS DOWN 

Underactive thyroid

Cost: From £10

Hypothyroidism (an underactive thyroid) causes slower metabolism, leading to symptoms including fatigue and weight gain. It affects roughly one in 50 people.

Rapid home-testing kits screen for raised TSH – a hormone that tells the thyroid gland to produce other hormones that directly affect our metabolism; high levels of TSH signal the thyroid is underactive.

The home kits involve placing a pin-prick blood sample in a cassette (which looks like a Covid-19 lateral flow test). Results appear ten minutes later – a coloured line indicates raised TSH levels.

Expert verdict: ‘These home tests are reasonably reliable for identifying whether TSH is above a certain threshold – which is a key indicator of an underactive thyroid,’ says Dr Nirusha Kumaran, a GP specialising in hormonal issues at Founders Health, a private London clinic.

‘However, I wouldn’t rely on it for a diagnosis. Not only can it be prone to false positive results, but more importantly TSH level should be accompanied by readings of other hormones, known as FT4 and FT3, for a full picture of thyroid function, and these are not tested for by at-home kits.

‘Ask your GP about a proper laboratory thyroid function test – or buy one that you send off to an accredited lab (costs from £30). These are more informative and clinically useful because they are able to pick up these other hormones which basic home tests cannot do.’

Verdict: NEUTRAL 

Diabetes

Cost: From £13

Raised blood glucose levels are a key feature of diabetes. The at-home glucose monitor involves placing a drop of blood (via fingerprick) on a plastic strip. The reading, in millimoles per litre (mmol/L) appears on its screen within seconds. A normal reading is 4.0 to 5.4 mmol/L (fasting), or up to 7.8mmol/L two hours after eating.

Expert verdict: ‘Glucose meters provide a snapshot of your blood sugar,’ says Dr Mark Vanderpump, a consultant endocrinologist in London, specialising in diabetes.

‘They’re most useful for people with established diabetes to monitor levels and assess their response to treatment – but they can also help indicate a new diagnosis.

‘If you don’t have diabetes but experience symptoms such as unexplained weight loss, constant thirst and passing urine more frequently, it is reasonable to check your blood glucose using a meter like this.

‘Note, a single blood-sugar reading with this home test can be misleading – so repeat several tests over a few days for greater accuracy, and make sure it’s done on an empty stomach or at least two hours after a meal.

‘Any raised reading should then be followed up with a doctor’s appointment for formal medical testing that involves a HbA1c blood test (a measure of average blood glucose over a three-month period).’

Verdict: THUMBS UP 

Prostate cancer

Cost: From £13

These measure PSA, a protein in the blood – raised levels can be a sign of prostate cancer. You put a drop of blood on the testing cassette and results appear onscreen in ten minutes. indicating either a ‘positive’ (i.e. raised PSA) or ‘negative’ (normal PSA, around 4ng/ml). Some tests can be sent to a laboratory in an enclosed envelope for further analysis (from £30).

Expert verdict: ‘A raised PSA is an indicator of a possible issue with the prostate rather than a diagnosis, so these tests should be treated with caution,’ says Neil Barber, a consultant urologist at Frimley Health NHS Foundation Trust.

‘If you’re suffering symptoms such as more frequent urination at night, you could try a rapid home test to see if your PSA is raised – and if it is, then speak to your GP for a more formal evaluation of possible causes (these can include an enlarged prostate and cancer, but are also affected by exercise and sexual activity). Equally, if you’re having worrying symptoms, you could go straight to your GP without doing a home test at all.

‘But note, no at-home test is going to be as accurate as laboratory tests, where you’re told your specific PSA, rather than a simple positive/negative.

‘Laboratory test results also take into account other factors, such as your age (PSA naturally increases with age), so the instant home tests are limited in what they can tell you.’

Verdict: NEUTRAL 

Bowel problems

Cost: From £13

Many rapid home-testing kits claim to be able to identify microscopic specks of blood in stool samples – a sign of colon cancer, polyps or inflammation – within five minutes. A ‘positive’ reading means blood has been detected.

Expert verdict: ‘The rapid home kits are different from the FIT (faecal immunochemical test) offered to people aged 50 to 74 in the UK as part of the NHS bowel screening programme – because the FIT test measures the actual amount of blood in stools which can be a sign of cancer, piles or inflammation which needs further investigation,’ says Dr Rehan Haidry, a consultant gastroenterologist at the Cleveland Clinic, London.

‘In contrast, the rapid result is what we call qualitative – where the result is either “positive” or “negative”. But it can be more helpful to know there is blood in the stool rather than how much – as this is a springboard for the next step, such as a medical examination or further tests, to find out what’s causing it. Even the most basic home tests can accurately detect any blood just like the ones sent to a laboratory, so in that sense both are useful.

‘Bear in mind that any bleeding could be intermittent and not necessarily a reason to worry, but should always be followed by a GP appointment.’

Verdict: THUMBS UP 

Menopause

Cost: From £5

This test looks for elevated levels of follicle-stimulating hormone (FSH) – levels typically rise as ovaries run out of eggs, so high levels can act as a biomarker of the menopause. You dip a test strip into a urine sample – and, much like a pregnancy test, a dark double line indicates a positive result (i.e. you are in menopause).

Expert verdict: ‘FSH levels rise as ovarian function declines, but we also know levels fluctuate significantly during perimenopause [the period leading up to menopause] – meaning a single measurement cannot reliably confirm or exclude menopause,’ says Dr Claire Phipps, a GP and menopause specialist at London Gynaecology, a private clinic.

‘For this reason, we don’t recommend either an at-home rapid hormone test, or the kits you send away to a laboratory, if you’re over 45 because results can be so misleading.

‘In line with NICE guidelines, the diagnosis of peri/menopause in women over 45 is usually done by a doctor based on age, symptoms and menstrual history rather than hormone testing.’

Verdict: THUMBS DOWN 

Allergies

Cost: From £50

These claim to identify allergies to pollen, pet dander, dust or foods. A finger-prick blood sample is sent for analysis, where a lab detects the concentration of different immunoglobulin E (IgE) antibodies, made by the body in response to allergy triggers. Results are often available within three days to a week.

Expert verdict: ‘In allergy clinics, we frequently perform skin-prick testing, where the allergen is introduced and we’re looking for a raised, itchy skin reaction to it,’ says Dr Michael Tarzi, a consultant immunologist at University Hospitals Sussex NHS Foundation Trust.

‘The basis is the production of specific antibodies. So, for example people with cat allergy have an IgE antibody that specifically recognises cat dander allergens, which would be different from the IgE antibody that people with hay fever produce that recognise pollen allergens. We can detect these antibodies in the blood – that’s how the allergy tests you send away work.

‘However, for at-home DIY kits, the difficulty is knowing the analytical accuracy of the laboratory tests – as most of the private providers don’t publish information about which methods they’re using.

‘Plus, without a clinical history to go with any antibody measurement, these results may still be misleading – indeed many people without an allergy have raised levels of IgE, while some with an allergy have normal levels, so it is very complicated.’

Verdict: THUMBS DOWN