What are the Kidney Funtions Tests?
Kidney function tests, also known as renal function tests, is an important test in evaluation of kidney status.
The test measures the level of vatoius subatances in the blood such as of urea, electrolytes and creatinine (UECs).
Erea and creatinine are waste products excreted through the kidneys. The kidneys also paly a critical role in mainraining the balance of electrolytes such as sodium, potassium and chloride. If there is a problem with kidneys, the levels of these substances change in blood.
Inadditional to diagnosis and monitoring of kidney diseases, these thesrs are useful in monitring other condions such as heart disease, diabetes and high blood pressure
Why the UECs Test is done
Since your kidney’s play a cental role in maniting normal function of your body, there is a wide variety of situations when the kidney function tests are necessary.
This includes:-
- for individuals with suspected kidney problems,
- high blood pressure,
- heart disease,
- diabetes, or
- Those taking medications that might affect the kidneys such as ARVs, NSAIDS, chemotherapy
- Acute conditions such as blood loss, Severe sepsis, vomiting/diarreahea
- Before major operation or some procedures such as contrast imaging
- Before starting chemotherapy
- As part of preventative health and well being checkup
- …and many others!
Patient Preparation/Instructions
No special preparation is usually required for these tests.
However, healthcare providers may advise patients to avoid certain medications or fast for a few hours before the test. It’s important to follow any specific instructions given by the healthcare provider.
Typical Reference Values for Renal Function Tests
The typical reference values include normal ranges for electrolytes, minerals, protein, waste products, and estimated glomerular filtration rate (eGFR). Any result lower than 60 millilitres/minute/1.73m2 may be a warning sign of kidney disease.
Refence values for the Kidney function tests are summarised below:-
| Test Component | Sample Type | Reference Range (SI Units) | Notes |
| Creatinine | Serum | Adult Male: 64–104 µmol/L <br> Adult Female: 49–90 µmol/L | Ranges can vary significantly with age, particularly in children and adolescents. Higher levels suggest reduced kidney function. |
| Urea (BUN) | Serum | 2.5–7.14 mmol/L (or 2.1–8.5 mmol/L) | Reflects protein metabolism and kidney excretion. Can be influenced by diet, hydration, and other non-renal factors. |
| eGFR | Calculated | Normal: ge90 mL/min/1.73 m2 | Estimated Glomerular Filtration Rate. Calculated using serum creatinine, age, sex, and sometimes race. Declines naturally with age. <br> Mildly decreased: 60–89 mL/min/1.73 m$^2$ <br> Severely decreased: $\< 15$ mL/min/1.73 m$^2$ |
| Sodium | Serum | 135–145 mmol/L | Crucial for fluid balance and nerve function. |
| Potassium | Serum | 3.6–5.5 mmol/L | Crucial for fluid balance and nerve function. |
| Chloride | Serum | 97–105 mmol/L | Crucial for fluid balance and nerve function. |
| Bicarbonate | Serum | Arterial: 22–29 mmol/L | Crucial for fluid balance and nerve function. |
| Venous: 23–29 mmol/L | Crucial for fluid balance and nerve function. | ||
| Calcium (Total) | Serum | 2.0–2.6 mmol/L | Important for bone health and many bodily functions. Kidney disease can affect calcium levels. |
| Serum | |||
| Phosphate | Serum | 1.1–1.45 mmol/L | Important for bone health. Kidneys excrete phosphate, so high levels can indicate kidney dysfunction. |
| Magnesium | Serum | 0.6–1.1 mmol/L | Important for nerve and muscle function. Can be affected by kidney disease. |
| Albumin | Serum | 35–50 g/L (or 34–54 g/L) | A protein made by the liver. Low levels can indicate kidney damage (protein loss in urine) or liver disease. |
| Urine Albumin-to-Creatinine Ratio (uACR) | Spot Urine | Normal: $\< 30$ mg/g (or $\< 3$ mg/mmol) | Used to screen for and monitor albuminuria (protein in the urine), an early sign of kidney damage. <br> Moderately increased: 30–300 mg/g <br> Severely increased: 300 mg/g |
| Creatinine (24-hour) | 24-hour Urine | Adult Male: 7.7–21.3 mmol/24 hour <br> Adult Female: 5.9–14.1 mmol/24 hour | Reflects muscle mass and kidney function. Used to calculate creatinine clearance. |
How long do I wait for results?
It takes a few hours (typically 2-6) to complete analysis for kidney function tests. At Labtest Zote, we priritise timeliness for your results to ensure you get results fast for best outcomes.
How can I get tested for UECs?
To order UECs, click the “Order Test” button and add it to the cart.
The kidney function tests are available from our laboratory in Kilimani, Nairobi.
We offer home /workplace/ hotel sample collection at minimal cost within Kilimani and adjacent areas
