Overview
The kidney is a vital organ and plays an important role in the human body. They filter the waste products, toxins and excess nutrients that cannot be stored and will be flushed out through urine.
The functional unit of the kidneys is the nephron. The nephron contains the glomerulus, proximal and distal tubes and the collecting duct.
The kidney function test will play a major role in people affected with kidney diseases and Diabetes.
The kidney function test or renal function test has the ability to identify any kidney diseases or pathologies related to kidney disease, the response of the kidney to treatments, and determines the progress of kidney diseases.
A kidney function test is performed to evaluate the kidneys working condition. The test will help access the overall renal function.
According to the National Institute of Health, the overall prevalence of kidney diseases is approximately 14%, and the most common causes of kidney diseases are Hypertension and Diabetes.
Types of kidney function test
There are different types of kidney function tests, and your doctor will decide the set of tests required for the diagnosis. The types of Kidney function tests are listed below.
Urinalysis
A urinalysis tests for the presence of any blood or protein in the urine. A sample of urine will be collected from the patient, and the appearance of the urine will be analysed.
The concentration and content of the urine will also be analysed. When there is any infection or disease related to the kidney, the appearance of urine will be affected.
For example, if a person is affected with a Urinary Tract Infection (UTI), the microorganism present in the urine can make it look cloudy with a foul smell.
The presence of protein in the urine can be a sign of kidney disease. Urinalysis can be done to test for Diabetes, kidney disease and other disorders related to the kidney.
Serum creatinine test
Like the urinalysis, the creatinine test measures the kidney functioning ability. Creatinine is a waste product that will be excreted out of the body through urine. It is a by-product of the energy-producing mechanism in the muscles.
The serum creatinine level in the blood should be relatively stable, and an increase in the blood level can indicate low or poor kidney function.
Blood urea nitrogen
The Blood Urea Nitrogen (BUN) test detects the presence of any waste products in the blood. The BUN test is a common test that is used to assess the working condition of the kidneys.
The BUN test helps to measure the urea nitrogen in the blood. The liver produces ammonia, which contains nitrogen. The ammonia will be broken down, and the proteins will be used by the body.
The left-out nitrogen will combine with other waste in the body, and it travels through the bloodstream. The waste, along with the blood, will reach the kidney through your bloodstream.
The kidneys filter the blood and the waste products effectively, and it will be flushed out. If the kidney does not function properly, then there will be a lag in the filtering process, and the blood urea will be relatively higher than normal.
Estimated GFR
The estimated glomerular filtration rate (eGFR) measures the blood filtration capability of the kidney. The test determines the factors such as weight, height, age and race.
Symptoms of kidney problems
Some of the symptoms may indicate that your kidney is not performing properly.
High blood pressure
High blood pressure can affect the kidneys. Abnormal blood pressure can lead to the narrowing of blood vessels. This can damage and weaken the body, including the kidney. High blood pressure and kidney diseases are interlinked.
Blood in the urine
Blood in the urine can indicate that the kidney is not filtering the waste products and blood properly. Haematuria is the condition in which the kidneys allow the blood to flow through the urine.
Urinary tract infection can cause blood to leak into urine. The bacterial infection makes the urine appear cloudy with a foul smell.
Frequent urges to urinate
The urge to urinate often occurs when there is a urinary tract infection. The bacterial infection enters through the urethra and causes pain and discomfort while urinating. It can cause pain during urination.
Difficulty beginning urination and painful urination
Hesitation to urinate or pain during urination can indicate a kidney infection. When there is chronic kidney disease, pain during urination occurs.
How is the test performed?
The urine sample collection can be done at home, and no special preparation will be required unless your doctor mentions any specific instructions.
Preparing for the test
The preparation for the test will depend on the type of test. For a 24-hour test, the collection method will be different.
- When you wake up in the morning, urinate as usual.
- After that, collect the sample in the container which your healthcare provider has given.
- Collect the urine in the container when you wake up the next day.
- Drop the test sample at the laboratory.
Taking a clean catch urine sample
Make sure you only collect the sample in the container which was provided by your lab technician. Make sure you collect the sample in a clear container without any contaminants.
Interpreting the results of your urine concentration test
Interpreting the test results will be done by your doctor. Do not try to self-analyse. When you get the results, visit your doctor.
If you have any readings that are high than the normal range, your doctor might prescribe you certain medications.
The results can clearly tell you whether the kidney is functioning properly or if there is any lag in the organ function.
When to see a doctor?
Consult a doctor if you have the following symptoms.
- Pain during urination,
- Hesitation to urinate,
- Cloudy urine assisted by a foul smell,
- High blood pressure,
- Blood in urine and
- Swelling of hands and legs due to fluid build-up.
Conclusion
A kidney function test helps to determine any lag in kidney function. If a person exhibits any symptoms of Diabetes or high blood pressure kidney function test will be required.
A kidney function test can predict chronic kidney diseases. The kidney function test depends on the doctor’s prescription and the patient’s aetiology.
Sometimes, chronic kidney disease can be prevented with the help of a kidney function test. So, it is recommended to visit your doctor at regular intervals and be aware of your health conditions.
