Having creatinine levels in your blood above 1.2 mg/dL for males and 1.0 mg/dL for females may indicate a potential issue with your kidneys, such as an infection or kidney disease.
Creatinine is a waste product that occurs naturally in your body when your muscle tissues break down.
Measuring creatinine levels can provide insights into how your kidneys are functioning. Your kidneys filter creatinine and other waste products from your blood, which are then excreted through urine.
A doctor can measure creatinine levels in both your blood and in your urine. Creatinine levels that are either above or below normal ranges may indicate the presence of an underlying health condition.
Keep reading to learn more about how creatinine levels are measured, what your results might indicate, and any symptoms you might experience.
Creatinine levels can be determined using a blood test or a urine test.
Blood creatinine test
A creatinine blood test, also known as a serum creatinine test, is one of several tests used to examine how well your kidneys are filtering blood.
During this test, blood is collected from a vein in your arm and is then sent to a lab for further analysis.
Blood serum creatinine ranges are usually measured in micromoles per liter (micromol/L) and milligrams per deciliter (mg/dL).
The normal blood serum creatinine ranges for adult males and females is typically:
- Males: 60 to 110 micromol/L (0.7 to 1.2 mg/dL)
- Females: 45 to 90 micromol/L (0.5 to 1.0 mg/dL)
Creatinine levels above the normal range values may be considered high.
However, it’s important to note that creatinine-level tests don’t tell the full story. According to the National Kidney Foundation, several factors may determine your “normal” creatinine levels.
As such, people with creatinine levels within these ranges may actually have kidney disease, while people with results outside of these ranges may not.
A doctor may want to confirm these values by using a urine test or by repeating the blood test.
| Creatinine levels | Males | Females |
|---|---|---|
| Low | below 0.7 mg/dL | below 0.5 mg/dL |
| Normal | 0.7 to 1.2 mg/dL | 0.5 to 1.0 mg/dL |
| High | Above 1.2 mg/dL | above 1.0 mg/dL |
A note on reference ranges and results
Creatinine levels may vary due to factors like age, sex, hydration, and body composition. Additionally, standard reference ranges could vary from lab to lab.
It’s important that you don’t try to interpret your results on your own. A doctor can help you evaluate and interpret your results and what they may mean.
Urine creatinine test
A doctor may collect a single urine sample for this test, but they’ll most likely request a 24-hour sample called a urine albumin-to-creatinine ratio (UACR).
This test checks to see whether a protein called albumin “leaks” into your urine. A normal test result is 30 milligrams per gram (mg/g). A result above this may be a sign of kidney disease.
A UACR test can be used in conjunction with glomerular filtration rate and creatinine clearance to determine kidney health.
In general, high creatinine levels can indicate that your kidneys aren’t working well.
There are many possible causes of high creatinine, some of which may not be related to your kidneys. These may include:
- being dehydrated
- having a high protein diet
- exercising regularly
- being pregnant
- taking the supplement creatine
However, other causes of high creatinine may be a sign of an underlying health condition that could require medical treatment. Many of these conditions can cause damage or disease that impacts kidney function.
These may include:
- drug toxicity (drug-induced nephrotoxicity)
- kidney infection (pyelonephritis)
- glomerulonephritis
- diabetes
- high blood pressure
- heart disease, such as atherosclerosis or congestive heart failure
- blockage of the urinary tract
- kidney failure, both acute and chronic
The symptoms of high creatinine may depend on the condition that’s causing it.
Drug toxicity (drug-induced nephrotoxicity)
Some medications can cause damage to the kidneys and impair their ability to function. Examples of such drugs are:
- antibiotics, such as aminoglycosides, rifampin, and vancomycin
- cardiovascular drugs, such as ACE inhibitors and statins
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- immunomodulators
- antiviral drugs
- anticonvulsant drugs
- chemotherapy drugs
- diuretics
- lithium
- proton pump inhibitors
Symptoms that go along with high creatinine and can develop rapidly may include:
- fluid retention, particularly in your lower body
- passing low amounts of urine
- feeling weak or fatigued
- confusion
- nausea
- shortness of breath
- irregular heart rate
- chest pain
Kidney infection (pyelonephritis)
A kidney infection is a type of urinary tract infection (UTI). It can happen when bacteria or viruses infect other parts of your urinary tract before moving up into the kidneys.
If left untreated, kidney infections can cause damage to your kidneys and even kidney failure. Some kidney infection symptoms to look out for
- fever
- pain localized to your back, side, or groin
- urination that’s frequent or painful
- urine that appears dark, cloudy, or bloody
- bad-smelling urine
- chills
- nausea or vomiting
Glomerulonephritis
Glomerulonephritis occurs when the parts of your kidneys that filter your blood become inflamed. Some potential causes include infections or autoimmune diseases like lupus and Goodpasture syndrome.
Glomerulonephritis can lead to kidney scarring and damage as well as kidney failure. Symptoms of the condition include:
- blood in the urine, which may make it appear pink or brown
- urine that appears foamy due to high levels of protein
- fluid retention in the face, hands, and feet
- urinating less frequently
- joint pain
- skin rash
- abdominal pain
- jaundice
Diabetes
Diabetes is a condition in which your blood sugar is too high. Elevated blood sugar levels can lead to a variety of health problems, one of which is kidney disease.
There are two types of diabetes — type 1 and type 2. Symptoms of type 1 diabetes can develop quickly while symptoms of type 2 often develop gradually.
General symptoms of unmanaged diabetes may include:
- feeling very thirsty
- frequent urination
- increased appetite
- feeling fatigued
- blurry vision
- sensations of numbness or tingling in the hands and feet
- unexplained weight loss
High blood pressure
High blood pressure happens when the force of the blood pushing on the walls of your arteries is too high. This can damage or weaken the blood vessels around the kidneys, impacting kidney function and causing high creatinine.
Since high blood pressure often has no symptoms, many people don’t know they have it. It’s often detected during a routine health screening.
Heart disease
Conditions affecting the heart and blood vessels, such as atherosclerosis and congestive heart failure, can also impact kidney function. These conditions can affect blood flow through the kidneys, leading to damage or loss of function.
Symptoms of atherosclerosis don’t usually occur until an artery is severely narrowed or completely blocked. They can also depend on the type of artery affected.
Some symptoms may include:
- chest pain (angina)
- shortness of breath
- abnormal heartbeat (arrhythmia)
- confusion
- muscle weakness
- feeling tired or weak
- stroke-like symptoms, such as paralysis or trouble speaking
Common symptoms of congestive heart failure can include:
- difficulty breathing or shortness of breath
- feeling tired or fatigued
- swelling in the abdomen, legs, or feet
Urinary tract blockage
Your urinary tract can become blocked due to a variety of things, such as kidney stones, an enlarged prostate, or tumors. When this happens, urine may accumulate in the kidneys, leading to a condition called hydronephrosis.
Symptoms of a urinary tract blockage can develop quickly or slowly over time depending on the cause. Some signs to look out for in addition to a high creatinine level include:
- pain in your back or side
- frequent or painful urination
- blood in your urine
- passing small amounts of urine or having a weak urine stream
- feeling tired or fatigued
Kidney failure
Kidney failure occurs when your kidney function is less than 1
Kidney failure can be either acute or chronic. The symptoms of acute kidney failure can come on quickly while those of chronic kidney failure develop over time.
Some symptoms of kidney failure to watch for
- fluid retention, particularly in your lower body
- passing low amounts of urine
- feeling weak or fatigued
- headache
- confusion
- nausea
- trouble sleeping
- muscle cramping
- feeling itchy
- shortness of breath
- chest pain
Speak with a doctor if you’re experiencing new, unexplained, or recurring symptoms, such as changes in your urinary patterns.
A doctor will work with you to evaluate your symptoms and determine the treatment that’s right for you.
It’s important to remember that chest pain and acute kidney failure should always be taken seriously. You should be sure to seek immediate medical attention if you’re experiencing either one.
Treatment for high creatinine levels will depend on the underlying cause.
In many cases, medications may help. For instance, antibiotics may be prescribed to treat a kidney infection, while blood pressure medications could help manage your levels.
In cases of kidney failure, dialysis may be required in addition to medications to help filter toxins and waste products from your blood. In severe cases or end-stage cases, a kidney transplant may be required.
A healthcare professional can help develop the best treatment plan for you.
What level of creatinine indicates kidney failure?
Healthcare professionals use the estimated glomerular filtration rate (eGFR) to measure how well your kidneys filter blood in one minute. This test uses your serum creatinine levels, age, and sex. According to the National Kidney Foundation, an eGFR test result of 15 mL/min or lower is a strong indication of kidney failure.
Can drinking water lower creatinine?
Drinking water may lower creatinine levels for a short period only. Your levels will most likely rise back up if you have an underlying health condition that affects your kidneys.
Creatinine is a waste product that occurs naturally in your body when your muscle tissues break down. A doctor can use a creatinine test to help assess the function of your kidneys.
A hig creatinine level may indicate kidney disease, but it’s important to note that many factors can determine your normal creatinine levels.
A healthcare professional can help you understand your test results and develop an appropriate treatment plan if you have high creatinine levels.