Kidney conditions explained

Three conditions that are closely linked

Your kidneys filter your blood. They remove waste and extra fluid, help control blood pressure, and help keep the balance of salts and minerals in your body. When something affects the small blood vessels in the kidneys over many years, the kidneys can slowly lose some of that ability.

Diabetes and high blood pressure are the two most common causes of chronic kidney disease (CKD) worldwide. Both conditions can damage the tiny filters in the kidneys over time. The link also runs the other way: kidney disease can push blood pressure up, and people with CKD are more likely to have heart and blood vessel problems.

This is why a doctor who is treating diabetes or high blood pressure will often ask for kidney tests, even when a person feels completely well. Many people have more than one of these conditions at the same time, so the pages below link to each other.

Chronic kidney disease

Chronic kidney disease means signs of kidney damage or reduced kidney function that have lasted for more than three months. It is common, it often causes no symptoms in its early stages, and it is found through blood and urine tests rather than by how a person feels.

Diabetes and the kidneys

Diabetes (many people in Mombasa simply call it sukari) raises the level of sugar in the blood. Over years, high blood sugar can damage the small blood vessels in the kidneys. The first sign is often a small amount of a protein called albumin leaking into the urine, long before any symptoms appear.

High blood pressure and the kidneys

Many people know high blood pressure as presha. It is often thought of as a heart problem, but it matters for the kidneys too. High pressure in the blood vessels can damage the kidneys' filters over time, and damaged kidneys find it harder to control blood pressure.

Why these conditions are often silent, and why tests matter

Early kidney disease rarely causes pain or obvious symptoms. Swelling of the feet, tiredness or changes in urine usually appear later, if at all, and they have many other possible causes. For this reason, kidney health is checked with tests.

Two tests do most of the work:

• eGFR (estimated glomerular filtration rate). This is worked out from a blood creatinine result using a validated equation that also takes age and sex into account. It estimates how well the kidneys are filtering. Read about eGFR.
• Urine ACR (albumin to creatinine ratio). This measures albumin, a protein, in a urine sample. Healthy kidneys let very little albumin through. Read about urine ACR.

International guidance from KDIGO (Kidney Disease: Improving Global Outcomes) says CKD should be assessed using both eGFR and albuminuria (albumin in the urine) together, and that the changes must last for more than three months. A single high creatinine result does not on its own mean a person has kidney disease. If that is why you are here, the high creatinine guide is a good place to begin.

Which page should I start with?

• "I have diabetes." Start with diabetes and kidney health.
• "I have pressure." Start with high blood pressure and your kidneys.
• "I was told I have CKD." Start with chronic kidney disease: what you need to know, then CKD stages.
• "I have a result and I don't understand it." Go to I have a kidney test result.
• "I'm not sure." Try not sure what you need? and answer one question.

Tests and care in Mombasa

In Mombasa, most people get kidney tests from a private laboratory or a hospital outpatient clinic, then take the printed results to a doctor. Blood and urine tests for kidney function are widely available across Mombasa Island, Nyali, Bamburi, Likoni and Changamwe. A general doctor or physician can usually arrange the first tests and explain them. Some people are later referred to a nephrologist, a doctor who specialises in the kidneys.

If you would like help finding an appropriate verified provider, see kidney care in Mombasa or kidney testing in Mombasa.

This page explains what a test or condition involves. It is not a diagnosis and does not replace advice from a doctor who knows your history. Your results should be interpreted together with your symptoms, other tests and a clinical assessment. Medical disclaimer.