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Kidney Function Blood Test
Kidney Function Blood Test Call Us Today! 020 7499 1991

Kidney Function Blood Test

The kidneys serve as a filter for blood, retaining products that the body needs and filtering out waste products into the bladder to form urine. Certain blood tests measure the kidney’s function, checking different elements, usually the creatinine and urea waste products. These tests also check filtration rate and important salts, such as sodium and potassium.

A kidney function test is essential to a patient’s health screening at Medical Express Clinic. Your doctor may also recommend a health screening to investigate potential causes of illness. You shouldn’t worry about determining which tests you need; our doctor will do this and explain why you need the test during your consultation.

Our blood tests are available on the same day with a fast turnaround time. Our doctor will carefully explain your results after your test and organise any necessary next steps depending on your results.

What does a kidney function test measure?

The kidneys play a vital role in water and salt retention, including filtration, which affects blood pressure. Kidney function tests to assess how well your kidneys are working check several elements such as:

  • Urea

    Urea is a waste product from the breakdown of proteins in the body. If you have elevated urea levels in the blood, your kidneys may have a problem. It may also indicate bleeding in the gut or dehydration.

  • Creatinine

    This is a waste product from the muscles that enter the blood and is filtered by the kidneys into urine. If the kidneys deteriorate or fail, the creatinine levels will gradually rise. This is known as chronic kidney disease and is usually caused by kidney diseases, kidney blockage, or diabetes, and to a mild extent, old age.

    The creatinine level rises rapidly in an acute kidney problem, like acute kidney injury. This may result from infection, severe dehydration, or toxic medications, such as anti-inflammatories.

  • Glomerular filtration rate (eGFR, GFR)

    GFR provides information on the overall kidney function. It is a calculation from the creatinine levels, race, sex, and age,

  • Electrolytes

    Electrolytes are dissolved salts (potassium and sodium) in the blood. Problems with the liver can disrupt these salts, including medications, fluid overload, or dehydration caused by liver or heart failure.

What to expect

A kidney function test requires a blood sample collection. This procedure is simple and conducted by one of our specialists. We will send the blood sample to the laboratory for analysis, checking for toxins and salt to show your kidney function.

What can a kidney function test tell you?

A kidney function test can tell if you are at risk of suffering or developing a chronic kidney disease. Your result can also help you make better lifestyle choices, such as changing your diet, stopping smoking, and reducing alcohol consumption.

Symptoms of kidney damage

A poorly functioning kidney can cause chronic kidney disease, which presents the following symptoms.

  • Weight loss and loss of appetite
  • Fatigue
  • Swelling in the abdomen, ankles, wrists, or face

Early stages of chronic kidney disease may present no symptoms, so a kidney function test can provide insight into your kidney health before any severe damage. Some people have a higher risk than others for kidney problems. These include:

  • Binge drinkers
  • People with high blood pressure
  • People with existing heart conditions
  • People with diabetes
  • People taking certain medications (aspirin and ibuprofen)
  • People with a family history of kidney disease
  • People with continuous urinary tract infections
  • Overweight or obese people
  • Smokers

Damages to the kidneys are irreversible, but certain lifestyle changes can help prevent further damage to the kidneys.

Before treatment

Before treatment for kidney damage, you will have an appointment with a healthcare professional. During your consultation, you will inform the medical professional about your symptoms, medical history, and concerns. Your healthcare professional will also discuss if you need further diagnostic tests, like blood tests or scans, including additional costs before testing.

Preparing for treatment

We ensure that our patients have a seamless experience when visiting the clinic for consultation, testing, or treatment. You can easily access information on our food, visiting hours, parking, what to pack if you are staying with and other practicalities. Our dedicated team of private GP in London will also provide advice tailored to your needs.

The procedure

Blood testing involves using a syringe with a fine needle to draw a small amount of blood from a vein in the arm. You will only feel a slight sensation during this procedure. We will send the blood to a laboratory for testing, including any urine sample produced.


We will carry out your test after you have supplied urine or blood samples so you can go home immediately after your appointment. A blood sample collection is painless, and you will only feel a small pinprick from the needle entering your arm. You can return to work immediately after your test.

What to do next?

If your doctor referred you to us for testing, you can take your results to them, but if you want one of our doctors to discuss your result, book an appointment for a consultation. Fees are applicable for GP appointments.


When your results are available, the doctor will contact you to discuss whether or not you need treatment. If your test finds any abnormalities, you can access integrated medical care at our clinic, and our doctor will create a treatment plan to ensure your well-being. After the discussion with your doctor, we will email the result to you. We are available if you have any concerns or questions.

Blood testing for kidney function markers is available at Medical Express Clinic. Call 0207 499 1991 today to book an appointment for your kidney function test.

Frequently asked questions

If you need a kidney test, we can book you for it without a consultation, but you will interpret the result yourself or take it to your doctor. If you want to discuss any health concerns about your kidney test with the doctor or need their support to interpret your result, book an appointment for a GP consultation.

The early stages of kidney disease may not show symptoms but can be diagnosed through blood or urine tests. This makes being aware of your risks for kidney disease important. The risks for kidney disease are cardiovascular disease, high blood pressure, diabetes, and a family history of kidney disease.

Earlier diagnosis increases the chances of maintaining kidney health. The management and treatment of kidney disease include maintaining healthy blood pressure and sugar levels and medications to manage existing symptoms.