High creatinine and high blood pressure

Many people in Mombasa live with high blood pressure, often called presha. Doctors check creatinine regularly in people with high blood pressure, so it is common to see a high result on a routine report. This page explains how blood pressure and the kidneys affect each other, and what a raised creatinine may lead to.

A two-way relationship

Blood pressure and the kidneys are closely connected, and the link runs in both directions.

• High blood pressure can damage the kidneys. Over time, raised pressure strains and scars the small blood vessels and filters in the kidneys. Filtering can slowly fall, and albumin can start to leak into the urine. High blood pressure is one of the most common causes of chronic kidney disease.
• Kidney disease can raise blood pressure. The kidneys help control blood pressure by managing salt and water and by releasing hormones. When they are not working well, blood pressure often rises.

Because of this, a clinician looking at high blood pressure and a raised creatinine will think about which came first, and whether both need attention. Often, both do. Read more in can high blood pressure damage the kidneys?

Like early kidney disease, high blood pressure usually causes no symptoms. Many people feel completely well. That is why regular checks matter.

Why creatinine may be high in someone with high blood pressure

• Kidney damage from long-standing high blood pressure.
• An underlying kidney condition that is itself raising blood pressure.
• Blood pressure medicines. Some commonly used blood pressure medicines, which also protect the kidneys, can cause a small, expected rise in creatinine when first started or when the dose is increased. Doctors usually recheck the blood test within a few weeks. Water tablets (diuretics) can also raise creatinine if they cause dehydration.
• Dehydration or a recent illness, especially in someone taking water tablets.
• Anti-inflammatory painkillers, such as ibuprofen or diclofenac, which can reduce kidney function and raise blood pressure.
• Non-kidney factors, such as muscle mass, exercise, a meat meal or lab differences. See causes of high creatinine.

Kidney tests commonly used for people with high blood pressure

Guidelines such as NICE NG136 suggest that people diagnosed with high blood pressure have their kidneys checked. Tests commonly include:

• Creatinine and eGFR, to estimate kidney filtering. See eGFR explained.
• Urine ACR, to look for albumin. See urine ACR test.
• A urine dipstick, to look for blood in the urine. See urinalysis.
• Electrolytes, such as potassium and sodium, which some blood pressure medicines can affect.

Following KDIGO 2024, a clinician looks at eGFR and urine ACR together, over time. A single raised creatinine is not enough to diagnose chronic kidney disease. Changes must be present for more than 3 months.

For an overview of all the tests, see kidney function tests.

Why monitoring matters

Keeping blood pressure within the target your doctor sets is one of the most important ways to protect the kidneys. Your target depends on your age, other conditions and your kidney results, so ask what yours is. Home blood pressure readings, taken with a validated machine, can help your doctor see the full picture. Write them down with the date and time and bring them to appointments.

When a kidney specialist may be involved

Most people with high blood pressure and mildly reduced kidney function are cared for by a general doctor or physician. A nephrologist may be involved when, for example, blood pressure stays high despite several medicines, eGFR is low or falling quickly, there is a lot of albumin or blood in the urine, or high blood pressure appears at a young age. Read when to see a nephrologist.

Questions you might ask your doctor

• What is my eGFR, and has it changed since my last test?
• Do I need a urine ACR test?
• Could any of my medicines be affecting this result?
• What blood pressure target is right for me?
• When should I repeat these tests?

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.