Callum had bubbles in his urine. Doctors told him not to worry… now he’s on a transplant waiting list after being diagnosed with a disease that affects millions. Here are all the vital signs you can’t ignore

As a seemingly fit young man, Callum Renton initially presumed the throbbing back pain that hit him out of the blue was due to a muscle strain.

‘At the time I worked in a bank and spent most of the day sitting at a desk,’ says Callum, 25, a support worker from Fife, Scotland.

‘So I just assumed I’d pulled a muscle.’

He presumed the pain would ease in time, but instead the throbbing around his lower back got worse over the coming weeks – and soon was joined by another problem: a urinary tract infection (UTI).

‘I constantly needed to go to the loo, and my urine had bubbles in it and would sting when I passed it,’ he says.

‘And I felt tired all the time – I’d never had this before in my life.’

Callum then Googled his symptoms.

‘The word “kidney” came up, so I booked a GP appointment and asked if it could be that,’ he recalls.

‘But the doctor’s reply was: “No, you’re in your early 20s – you’re too young.” And he sent me home with antibiotics for the UTI.’

It took ten months of to-ing and fro-ing to his GP – and multiple courses of antibiotics for repeated UTIs – before he would get an accurate diagnosis.

Callum did indeed have a problem with his kidneys. In fact, it was such a serious problem that now, five years on, he needs dialysis three times a week and is on the waiting list for a transplant.

And astonishingly, his is not an uncommon story.

According to estimates by the charity Kidney Research UK, more than seven million people in the UK have chronic kidney disease (CKD), where the kidneys are damaged and cannot filter blood properly.

And this could be a vast underestimate; according to research published in The Lancet last month, up to half of kidney disease cases remain undiagnosed, possibly because of vague or a lack of symptoms in its early stages.

Indeed, in the early stages when the kidney disease can often be easily treated, symptoms such as itching and frothing urine – caused by protein in your urine, a sign the kidneys aren’t filtering as they should – get missed, says Professor Simon Davies, an honorary consultant nephrologist (kidney specialist) at the University Hospital of North Midlands.

‘The problem with kidney disease is that often symptoms are not there or very mild,’ he says.

The kidneys are like a sieve, he explains, filtering out toxins from the blood and expelling that and excess fluid as urine.

When they are damaged, symptoms may include ‘tiredness or loss of appetite – both caused by a build-up of toxins in your blood [which the kidney should filter out],’ says Professor Davies, who is also a trustee of Kidney Research UK.

‘But people feel tired for all sorts of reasons – it can often be overlooked for long periods of time.’

Fluid retention is often another sign of kidney disease, as the kidneys control the balance of fluid in the body.

‘This can be visible in the ankles, or the face, especially around the eyes’, says Professor Davies. But it can be confused for other things such as allergies or weight gain, he adds.

‘Recurrent UTIs can also be an indicator of kidney problems and should be investigated – however, again, there are many possible causes aside from kidney disease.’ This infection and related inflammation may also cause pain felt in the back, close to where the kidneys are located.

When symptoms are overlooked by patients or misdiagnosed by their doctors, kidney disease can progress by scarring the kidneys, causing a loss in kidney function over time, explains Professor Davies.

‘The earlier treatment is started, the better the chance of slowing down this progression, which is why it’s so important to identify the problem early on,’ he adds.

‘If left, it can lead to kidney failure, when the kidneys are working at less than 15 per cent function. Once kidney function drops to 7 per cent, either dialysis or a kidney transplant is needed to survive.’

The added frustration, he says, is that simple blood and urine tests can identify kidney disease.

‘The levels of a waste product called creatinine can be measured in your blood – and a doctor uses those results, plus your age, size and gender to calculate how many millilitres of waste your kidneys should be able to filter in a minute. This is known as your estimated glomerular filtration rate (eGFR).’

‘A urine albumin creatinine ratio (UACR) test can also be carried out to assess your kidney health. This measures the amount of protein in your urine, which can be an early sign of kidney damage.’

Professor Davies adds: ‘Yet when somebody is not believed to be at risk or symptoms are not identified as being related to kidney problems, they are unlikely to be given these tests.’

New research by the University of Glasgow found that in high-income countries including the UK, an estimated 30 to 50 per cent of chronic kidney disease cases are not diagnosed early enough to receive timely intervention.

Professor Davies says: ‘Kidney Research UK continues to call on the government to support the NHS to prioritise the prevention and early diagnosis of kidney disease, including an increase in the number of annual blood and urine tests to detect kidney damage.’

Callum was experiencing textbook symptoms as he was hit by one UTI after another.

‘Finally, after ten months of severe back pain, repeated UTIs, painful urination and constant tiredness, I went back to my GP and begged to be referred to a kidney specialist,’ he says.

‘By then had actually gained weight because I didn’t have the energy to be active.’

He waited seven months for a referral to a renal unit at hospital, where a test showed he had kidney dysfunction.

‘This was after ten months of pain and UTIs,’ he says. ‘But then I was put on yet another waiting list for a kidney biopsy to see how bad things were. I was started on blood pressure tablets and told I needed a kidney biopsy to find out what was causing the damage to my kidneys.’

Professor Davies says there are a ‘vast’ number of causes for kidney disease.

‘The most common causes of kidney disease are diabetes, which can damage the tiny filters in the kidneys, and high blood pressure, which can put a strain on the small blood vessels in the kidneys,’ he says.

However, there are other causes ranging from ageing, when kidneys may become smaller or lose some of their filtering units (called nephrons), making them less effective at removing waste and extra fluid from the blood.

Rising numbers of people with diabetes, high blood pressure and cardiovascular disease are projected to contribute to the number of people living with kidney disease, adding an additional 680,000 cases – and raising the total to 7.9 million – by 2033, according to a Kidney Research UK Report.

Genetics and lifestyle have a part to play – and more rarely it can be caused by autoimmune conditions, where the body mistakenly attacks the kidneys.

‘A young adult diagnosed with kidney disease is more likely to have been born with congenital abnormalities of the kidney and bladder,’ says Professor Davies.

‘This would prevent them from emptying their bladder properly, allowing infections to develop which can spread to the kidneys and cause damage. This can lead to further problems like high blood pressure which will make things worse.’

Callum was originally told his diagnosis was just ‘one of those things’.

It wasn’t until August 2022 – 18 months after his symptoms began – that he finally had a kidney biopsy, by which time his symptoms had worsened.

‘I lost weight, couldn’t get up in the mornings and vomited when I ate,’ he says. ‘I worked in a bank at the time and had to call in sick regularly.’

And the results were worse than they had expected. They showed he had IgA nephropathy (also known as Berger’s disease), an autoimmune condition where antibodies attack the kidneys’ filters gradually over time.

He needed dialysis, where a machine takes over the action of the kidneys, to remove extra fluid and waste products from the blood and maintain fluid and mineral balance – which in turn helps control blood pressure.

‘It was incredibly difficult to hear,’ says Callum.

‘Dialysis meant spending three days a week in hospital for four-and-a-half hours each session and completely changed my day-to-day life.’

Soon after his diagnosis, it was plain that Callum’s kidney function was declining ‘much faster than expected’.

He remained under the care of the renal team, had regular blood tests and monitoring, and continued taking blood-pressure medication (to reduce strain on the kidneys), but despite this his kidney function continued to decline.

While it is often not possible to cure kidney disease, steps should be taken to slow it down, says Professor Davies.

This could include prescribed medications and lifestyle changes, including making healthy food choices, keeping hydrated and managing other conditions that make it worse such as diabetes, high blood pressure and heart disease.

‘If left, CKD can lead to kidney failure, where the only option is dialysis or a kidney transplant.’

Around 7,000 people are currently waiting for a kidney transplant in the UK and six people die each week while on the waiting list.

‘On average, a kidney transplant lasts about 20 years, meaning people often need multiple in their lifetime,’ says Professor Davies. ‘It is a treatment, not a cure.’

Callum has dialysis three days a week for four-and-a-half hours each session. He had to leave his former job at a bank as a result and is on a kidney waiting list after it was discovered that none of his family are a suitable tissue match.

‘I try to enjoy life and carry on but I feel I am in a waiting game,’ he says.

‘I get tired a lot and can never make big plans as I always have to be near hospital for dialysis half the week.’

He firmly believes his young age delayed his diagnosis.

‘I don’t feel my physical symptoms were recognised as quickly as they should have been,’ he says.

‘I’m sharing my story so that anyone else with these symptoms receives the support, investigations and diagnosis they need as early as possible.’