Dr Sotomiwa Sotubo is a consultant nephrologist at the Lagos State University Teaching Hospital (LASUTH) and a lecturer at the state’s University College of Medicine (LASUCOM). In this interview with NKECHI ONYEDIKA-UGOEZE, she discusses the major causes and warning signs of kidney disease and explains how Nigerians can protect their kidney health.

What are the kidneys and their functions?
The kidneys are two bean-shaped organs located below the rib cage, toward the back of the body. Their major function is to filter the blood and remove waste products from the body. Every time we eat, our cells carry out metabolic processes that generate waste, which the kidneys help eliminate through urine.

The kidneys also remove excess water and help maintain the body’s fluid balance. This is why people whose kidneys are failing may begin to retain fluid, leading to swelling and other complications.

In addition, the kidneys produce important hormones and chemicals that are vital to the body. For example, they produce erythropoietin, a hormone that stimulates the production of red blood cells. When the kidneys are failing, erythropoietin production may decrease, resulting in anaemia. Patients may then experience low blood levels, fatigue and weakness.

The kidneys also help produce calcitriol, the active form of vitamin D, which is important for maintaining healthy and strong bones.

How common is kidney disease in Nigeria?
Kidney failure is a time bomb waiting to explode if we do not take urgent action. Currently, about one in 10 Nigerians is estimated to have some form of kidney disease, and I project that the number could increase significantly over the years if preventive measures are not strengthened.

With Nigeria’s population exceeding 200 million, this estimate would mean that more than 20 million people could be living with kidney disease. The major challenge is that the country does not have adequate infrastructure and resources to provide treatment for such a large number of patients.

For many Nigerians, access to dialysis remains difficult because of its high cost and limited availability. Some patients who progress to kidney failure require dialysis within a short period, while many others die because they cannot afford or access sustained treatment.

That is why prevention and early detection are crucial. Nigerians need to pay greater attention to the risk factors for kidney disease, undergo regular medical checks where appropriate and seek treatment early. Prevention, early diagnosis and effective management remain the best ways to reduce the burden of kidney failure in the country.

What are the risks associated with kidney disease, and who are the people majorly affected?
The number one risk factor for kidney disease currently in Nigeria is hypertension. This is why hypertension is often called the “silent killer”. Many people live with high blood pressure without knowing it until complications develop, one of which can be kidney damage or kidney failure.

For people who already have hypertension, it is not enough to simply take medication. They also need to monitor their blood pressure regularly to ensure that it is adequately controlled and that their medication is effective.

For those who are not hypertensive, regular medical check-ups are important, as early detection can help prevent complications.

Another major risk factor is diabetes. Globally, diabetes is one of the leading causes of chronic kidney disease, and in Nigeria, it is also a major contributor to kidney disease. This is followed by chronic glomerulonephritis, a group of conditions that cause inflammation and damage to the kidney’s filtering units.

Several other factors can increase the risk of kidney disease. These include obesity, prostate problems that obstruct the flow of urine, recurrent urinary tract or kidney infections, recurrent kidney stones and a family history of kidney disease.

Certain medications and substances can also damage the kidneys, particularly when they are used excessively, for prolonged periods or without medical supervision. These include some painkillers, such as diclofenac and ibuprofen. Excessive alcohol consumption and smoking can also increase the risk of kidney damage.

People who have any of these risk factors should take kidney health seriously and undergo regular medical evaluation. Early detection and proper management of underlying conditions such as hypertension and diabetes can significantly reduce the risk of kidney failure.
What age is appropriate for kidney screening?

I have seen patients as young as 13 and 18 years old on dialysis, which shows that kidney disease can affect people at a relatively young age. Generally, routine kidney screening can begin in adulthood, particularly from age 18.

If a person’s vital signs are normal and they have no known risk factors, screening can be done every two to three years. However, once someone reaches the age of 40, regular kidney checks become increasingly important and should be done more frequently.

People with a family history of kidney disease should also undergo screening more regularly. This is particularly important for those with established genetic conditions such as autosomal dominant polycystic kidney disease (ADPKD), which can run in families. Such individuals require closer monitoring and should discuss an appropriate screening schedule with their doctor.

What are the basic tests people should undergo to determine the health of their kidneys?
The basic tests include a kidney function test, which assesses how well the kidneys are filtering the blood, and a urinalysis to check for abnormalities in the urine. An important measure of kidney function is the estimated glomerular filtration rate (eGFR), which provides an estimate of how efficiently the kidneys are filtering waste from the blood.

These tests are relatively simple and widely available. If a urine test detects protein, particularly persistent protein in the urine, the person should see a doctor for further evaluation. Protein in the urine can be an early sign of kidney damage.

Sometimes, one of the earliest indications of kidney disease is proteinuria, or excess protein in the urine. This may cause the urine to appear unusually foamy, although foamy urine does not always mean that a person has kidney disease.

Other important checks include blood pressure, blood sugar and cholesterol levels, as hypertension, diabetes and cardiovascular risk factors are closely associated with kidney disease. Depending on the findings and the patient’s symptoms or risk factors, the doctor may request additional tests, including an abdominal ultrasound or other imaging studies.

The specific tests required will depend on the individual’s age, medical history, symptoms and initial test results. Early screening can help identify kidney problems before they progress to advanced disease.

What are the major signs that people should look out for?
The worrying thing about kidney disease is that it is often asymptomatic, particularly in its early stages. Many people do not experience any symptoms until the disease has progressed significantly.

For some people, one of the early signs may be unusually foamy urine. In such cases, they should visit a hospital for evaluation to determine whether they are losing protein in their urine, as persistent proteinuria can be a sign of kidney damage.

For others, symptoms may not appear until the disease has become advanced. Swelling of the legs, ankles or feet, for example, may indicate significant fluid retention.

Some people may also experience persistent tiredness, particularly when performing activities that previously did not leave them exhausted. Others may develop a metallic taste in the mouth, which can occur when waste products accumulate in the blood as kidney function deteriorates.

Blood in the urine is another warning sign that should not be ignored.

Anyone who notices blood in their urine should seek medical attention promptly.

People with hypertension should also pay attention to sudden changes in their blood pressure. If someone’s blood pressure has previously been well controlled with one or two medications but suddenly becomes difficult to control, it may be a sign that something has changed and should be medically investigated.

How true it is that high salt intake and seasonings can be harmful to the kidneys?
Excessive salt intake can put additional strain on the kidneys because the body has to eliminate excess sodium and maintain the appropriate balance of fluids. High salt consumption can also contribute to fluid retention and increase blood pressure.

Over time, persistent high blood pressure can damage the blood vessels and filtering structures in the kidneys, increasing the risk of chronic kidney disease. This is why we advise people to reduce their salt intake. Excessive salt consumption is also associated with an increased risk of hypertension. By reducing salt intake, people can help control their blood pressure and, in turn, reduce their risk of developing kidney disease.

As for seasoning products, many contain significant amounts of sodium. The issue is therefore not necessarily the seasoning itself, but the amount of sodium it contributes to the overall diet. People should use such products in moderation and check labels where possible to monitor their sodium intake.

How can people take care of their kidneys? Does regular water intake protect the kidneys?
One of the important things people can do is to stay adequately hydrated. Dehydration can affect the kidneys because, when the body lacks sufficient water, the kidneys have to conserve as much fluid as possible. Severe or repeated dehydration can contribute to kidney problems.

For most healthy adults, regular water intake is important, although the amount needed varies from person to person. A commonly recommended total daily fluid intake is around 2 to 2.5 litres, including fluids from food and other beverages. People who work under the sun, engage in strenuous physical activity, or sweat heavily may need more to replace the fluid they lose.

For people who are prone to kidney stones, adequate fluid intake is particularly important because it helps dilute the urine and can reduce the risk of stone formation. People who already have kidney disease or other medical conditions should, however, follow their doctor’s advice because some patients may need to restrict their fluid intake.

People should also avoid the excessive or prolonged use of painkillers, particularly non-steroidal anti-inflammatory drugs such as diclofenac and ibuprofen, unless they are prescribed or recommended by a healthcare professional.

Regular physical activity is another important part of maintaining kidney health. The World Health Organisation recommends at least 150 minutes of moderate-intensity physical activity per week for adults. This could be achieved through about 30 minutes of exercise on five days of the week. More activity may provide additional benefits for people who are able to do it safely.

Exercise helps with blood pressure control, weight management and overall cardiovascular health. It can also improve insulin sensitivity in people with diabetes. These are important because hypertension, diabetes and obesity are major risk factors for chronic kidney disease. Exercise should therefore be incorporated into a healthy lifestyle.

Do we have enough infrastructure, specialists and other resources to care for patients with kidney disease in Nigeria?
Unfortunately, we do not have enough. That is why we continue to emphasise prevention and early detection. We have many patients but relatively few nephrologists and other specialists available to manage kidney disease.

We also do not have enough dialysis machines and centres, while access to kidney transplantation and peritoneal dialysis remains limited. These gaps make it difficult for many patients with advanced kidney disease to receive sustained treatment.

The cost of treating advanced kidney disease is also a major challenge for patients and the health system. In many cases, prevention and early management are far more affordable than treating complications after the kidneys have failed.

We therefore need to strengthen prevention, screening and early treatment while also investing in dialysis services, transplantation, peritoneal dialysis, trained healthcare personnel and other aspects of kidney-care infrastructure.

The most effective approach is to prevent kidney disease where possible, detect it early and ensure that patients who develop the disease can access appropriate treatment before it progresses to kidney failure.