Healthy kidneys maintain the blood creatinine within a normal range. However, as kidney function declines, the kidneys may be unable to clear the creatinine level in the blood. Abnormally high levels of creatinine could indicate potential kidney malfunction or failure. For this reason, the doctors conduct a creatinine test (along with other tests) to determine how well your kidneys perform.

Any condition that affects the function of the kidneys is likely to elevate the creatinine level in the blood.  It is essential to work with your nephrologist to develop a treatment plan to address any medical issues that might be implicating your kidney function.

In this article, we will look at the definition of creatinine, the test to determine the creatinine levels in the blood, ways to lower creatinine levels, and myths about lowering creatinine.

What is Creatinine?

Creatinine is a waste product produced mainly by muscle activities from the breakdown of the compound called creatine. Creatine is a metabolite from creatine phosphate from muscle and protein metabolism, which the body uses to supply energy to the muscles. As the muscles use energy, the tissue that comprises the muscles break down naturally, releasing the creatinine into the bloodstream. Creatinine can build up in the blood from a high protein intake, intense workout, medication or supplement dosage, or if a person has a kidney problem.

Healthy kidneys filter creatinine from the blood and excrete it from the body through urine. However, impaired kidneys couldn't filter creatinine and other waste materials properly from the body, thereby causing waste buildup.

Hands holding a kidney frame

Doctors typically use a creatinine test to determine kidney function. However, checking the presence of creatinine alone in your blood isn't the best way to evaluate your kidney health since your creatinine level is dependent on your age, race, gender, and body size.

The best way to determine your kidney function is through Glomerular Filtration Rate (GFR). GFR is a calculation of your creatinine level, age, gender, race, and weight. Your GFR number will help your doctor determine if you have kidney disease. If your GFR number is below 60 for three months you may have kidney disease. Moreover, you may have kidney disease if your GFR number is above 60 with signs of kidney damage (presence of protein in the urine).

Creatinine Tests

Creatinine levels can be determined through two types of tests: a blood test and a urine test. The blood test a.k.a. serum creatinine test is often used as a preliminary test to determine the health of your kidneys.

A healthcare specialist will draw blood from a vein in your arm during this test, then send the blood samples to a lab for further analysis. Serum creatinine levels will elevate as kidney function declines.

creatinine blood test medicalnewstoday

In the case where your kidney function is very low, or your muscle mass is abnormal, a creatinine clearance test becomes necessary. Your doctor may likely request a random single 24-hour urine sample, which involves collecting your urine for 24 hours.

Serum Creatinine Normal Range

Serum creatinine is measured by milligrams (mg) of creatinine per deciliter (dL) of the blood.

The Mayo Clinic shared that the normal range of creatinine (for an adult) in the blood is generally:

  • Men: 0.6 to 1.2 mg/dL; 53 to 106 mmol/L
  • Women: 0.5 to 1.1 mg/dL; 44 to 97 mmol/L
  • Teenagers: 0.5 to 1.0 mg/dL
  • Children: 0.3 to 0.7 mg/dL

Meanwhile, the creatinine clearance is measured in milliliters (ml) of blood filtered per minute (min). The normal levels are:

  • 97 - 137 ml/min for males
  • 88 - 128 ml/min for females

For CKD patients, you may find your creatinine clearance below:

Stages of Renal Failure

Men

Women

GFR Levels
(both men and women)

Normal

SC: 0.6-1.2 mg/dl
CR: 97-137 ml/min

SC: 0.5-1.1 mg/dl
CR: 88-128ml/min

Higher than 90 ml/min

Mild

SC: 1.3-1.9 mg/dl
CR: 56-97 ml/min

SC: 1.2-1.9 mg/dl
CR: 56-88 ml/min

60 to 90 ml/min

Moderate

SC: 2.0-4.0 mg/dl
CR: 35-55 ml/min

SC: 2.0-4.0 mg/dl
CR: 35-55 ml/min

30 to 60 ml/min

Severe

SC: > 4.0 mg/dl
CR: < 35 ml/min

SC: > 4.0 mg/dl
CR: < 35 ml/min

Less than 30 ml/min

Important Note: For Serum Creatinine tests, see numbers in "SC" and for Clearance Rate tests see numbers in "CR" 

It is essential to note that this chart is for general reference. As mentioned, the serum creatinine normal range is dependent on a range of factors such as age, gender, hydration, or body mass. Hence, you must not interpret your lab results by yourself. Consult your doctor as they will evaluate and interpret your numbers and explain them to you.

Causes of high creatinine levels

Although high levels of creatinine are indicative of potential kidney problems, other possible reasons could elevate your creatinine levels. These reasons may be one-time occurrences, such as dehydration or intake of large amounts of supplement creatine or protein.

Other causes of high creatinine may suggest a health condition. These conditions can impair kidney functions or indicate kidney disease.

A few of these conditions include:

  • Kidney infection
  • High Blood Pressure
  • Drug toxicity (drug-induced nephrotoxicity)
  • Diabetes
  • Glomerulonephritis (inflammation of the tiny filters in your kidneys)
  • Heart diseases including congestive heart failure
  • Urinary tract blockage

Meanwhile, if your creatinine level elevation is caused by kidney problems, you may experience symptoms such as:

  • Chest Pain
  • Nausea
  • Muscle Cramps
  • Exhaustion
  • Vomiting
  • Fatigue
  • Swelling or fluid retention
  • Itchiness

How to lower creatinine levels without dialysis?

The symptoms of high creatinine can vary depending on the cause. When you have CKD or declining kidney function, you must do health measures to prevent further kidney damage and slow down CKD progression.

In cases of kidney failure, dialysis may become necessary on top of the medications to help your kidneys filter toxins and waste buildup.

Nevertheless, if you are still in the early stages of CKD, these tips below can help lower your creatinine levels.

1. Don’t take supplements containing Creatine

Hands holding Medications

Creatine provides the muscles with energy. It is stored in the brain, kidneys, and liver. Athletes and weightlifters use creatinine as a popular supplement to build muscle and improve performance. If you wish to lower your creatinine level, you may want to minimize your creatine intake.

Additionally, some medications such as antibiotics, cardiovascular drugs, chemotherapy drugs, diuretics, and lithium can also impair your kidney health. Consult with your doctor before taking any medications and supplements to protect your kidneys.

2. Reduce your protein intake

plant-based protein foods

What you eat can have an impact on your creatinine levels. Proteins and cooked meat have creatine, so consuming more than the recommended amounts of proteins could increase your creatinine levels. The heat in cooking causes the creatine, found in meat, to produce creatinine. Consider switching your red meat to more vegetable or plant-based dishes.

4. Eat more fiber

Adding more fiber into your diet can help lower creatinine levels in people with CKD. Great sources of fiber include whole grains, fresh fruits, vegetables, legumes, and nuts. While more research is needed to determine dietary fiber’s effects on creatinine levels, one study showed important reductions in creatinine levels among CKD patients who consumed more fiber.

fiber foods

5. Lower your salt intake

A high sodium intake can put a strain on your kidneys. Diets that have excess salt can also contribute to high blood pressure. Additionally, a high salt intake has been shown to shoot up the amount of protein in the urine, which could (further) lead to serious kidney damage

A high sodium intake can put a strain on your kidneys. Diets that have excess salt can also contribute to high blood pressure. Additionally, a high salt intake has been shown to shoot up the amount of protein in the urine, which could (further) lead to serious kidney damage

6. Talk with your healthcare provider about how much fluid you should drink

consult dietitian

While dehydration can increase the creatinine levels in the blood, fluid intake may be an issue if you have CKD. Discuss with your doctor about your fluid limit and the best time to drink them.

7. Avoid overusing NSAIDs

Over-the-counter painkillers such as non-steroidal anti-inflammatory (NSAIDs) drugs may also be harmful if taken too often or in large amounts over the recommended dosage. Consult with your doctor to discover the right treatments for pain and inflammation, as well as the frequency of dosage.

8. Limit your alcohol intake

saying no to alcohol

Alcohol consumption can be a tricky topic when it comes to kidney health. Some studies show that moderate alcohol consumption may help decrease the risk of CKD. On the other hand, excessive alcohol consumption can also elevate your blood pressure. High blood pressure is one of the common reasons for high creatinine levels, as well as one of the causes of kidney disease. Fortunately, you can prevent this from happening by reducing your alcohol intake or giving up on alcohol altogether.

Myths or Facts?

There is plenty of online information about lowering creatinine levels that have opposing ideas. Sifting through these misconceptions can help you manage your creatinine levels better and protect your kidney health. Here are a few of them:

- Can Oatmeal Lower Creatinine Levels?

In a study conducted on CKD patients, eating oats didn’t show any changes in creatinine levels in kidney disease patients. Oatmeal has contains a significant amount of phosphorus and potassium, minerals that CKD patients should closely monitor. 

oatmeal in a bowl

Instant oatmeal is heavy on sugar that can be put a strain on your kidneys. However, oatmeal is rich in fiber and loaded with nutrients that lower cholesterol, and blood sugar. You can still include oatmeal in your diet but opt for minimally processed oats such as steel oats.

- Can Chitosan Lower Creatinine levels?

Chitosan is an ingredient found in plenty of weight loss shakes and supplements that aim to lower cholesterol. In a study conducted among eighty patients with renal failure, half of the patients have been fed with 30 chitosan tablets (45 mg chitosan/tablet) thrice a day. 

Chitosan tablets

Patients who took chitosan have shown reduced total serum cholesterol levels (from 10.14 ± 4.40 to 5.82 ± 2.19 mm) and increased serum hemoglobin levels (from 58.2 ± 121 to 68 ± 9.0 g L−).  After 12 weeks of ingestion, the patients reported an improved feeling of strength, appetite, and sleep quality.

While these data suggest that chitosan may be effective in lowering creatinine levels, further studies are still needed to support the use of Chitosan to lower creatinine levels. Talk to your doctor before using chitosan or any other supplement.

- Can Coffee Lower Creatinine Levels? 

Drinking coffee may have some benefits, but it can result in elevated high blood pressure, which can be harmful to your kidney disease. Coffee is a natural diuretic, which helps the body remove excess fluid. 

black coffee in a cup

They are also found to decrease glomerular filtration rate (GFR) and cause metabolic interruption that can raise the risk of cardiovascular diseases. Before taking diuretics, talk to your doctor, especially if you are taking other medications.

- Can Garlic Lower Creatinine Levels?

Garlic is a natural antibiotic and antifungal food that offers plenty of health benefits. A study suggests that garlic increases the body’s production of nitric oxide that can reduce hypertension. 

garlic cloves

Nitric oxide production allows blood, nutrients, and oxygen to travel to each part of the body effectively and efficiently. Garlic lowers blood pressure and is a good antioxidant known to remove toxins from the body. As a result, lower blood pressure can help lower the creatinine levels in the blood.

- Can Turmeric Lower Creatinine Levels?

Turmeric is generally safe for healthy individuals when used in small amounts. However, it may cause adverse reactions in some people. High doses of turmeric or consumption for long periods may trigger digestive problems such as constipation, diarrhea, nausea, and acid reflux. 

Curcumin, the active compound found in turmeric, may help in slowing down CKD progression and prevent kidney problems due to its antioxidant and anti-inflammatory properties. Nevertheless, more research is needed to verify its safety and effectiveness.

- Can Fasting Lower Creatinine Levels?

There’s limited study on fasting and kidney disease. The most relevant study conducted was focused on CKD patients who fast during Ramadan, a religious observation that involves fasting and abstinence during daylight hours. Researches have found that a few CKD patients in stage 3 or higher experience worsened kidney function, increase heart disease risk, kidney damage, or acute kidney failure. In brief, further studies are still needed to determine if fasting can lower creatinine levels.

Supplements and Medications to Lower Creatinine Levels

If the cause of the high levels of creatinine in the blood is kidney disease, your doctor will prescribe you medications to manage the symptoms. These prescription drugs include:

  • Angiotensin - converting enzyme (ACE) inhibitors like Lotensin (benazepril) and Capoten (captopril) and Angiotensin II Receptor Blockers (ARBs) like Edarbi (azilsartan) and Teveten (eprosartan) to manage high blood pressure. ARBs also reduce the amount of protein in the urine.
  • Erythropoiesis - stimulating agents (ESAs) to help improve your red blood cell count.
  • Phosphate or potassium binders help your kidneys filter extra phosphate and potassium.

The Bottom line

Creatinine levels can change quickly, even throughout the day. A single blood test that shows high creatinine in the blood may not be a cause for concern. However, if several tests in a row show elevated levels, it could indicate serious kidney problems. Listed below, are ways to manage or avoid high levels of creatinine:

  • Steering clear from creatine supplements
  • Minimizing protein intake
  • Managing your sodium intake
  • Eating more fiber
  • Avoiding overusing NSAIDs
  • Keeping your body hydrated
  • Knowing your fluid limit
  • Limiting your alcohol intake

High levels of creatinine should, without delay, be addressed to decrease the risk of other complications. But at the end of the day, it is always wise to check in with your doctor to determine the best course of treatment for your kidney disease.

Sources:

Effect of Chitosan on Renal Function in Patients with Chronic Renal Failure - https://onlinelibrary.wiley.com/doi/abs/10.1111/j.2042-7158.1997.tb06099.x

Effect of chitosan on renal function in patients with chronic renal failure - https://pubmed.ncbi.nlm.nih.gov/9255718/

Dietary fiber effects in chronic kidney disease: a systematic review and meta-analysis of controlled feeding trials - https://www.nature.com/articles/ejcn2014237

Foods with added fiber lower serum creatinine levels in patients with chronic kidney disease - https://pubmed.ncbi.nlm.nih.gov/22739658/

#KidneyWk 2019: Intermittent Fasting and Kidney Disease - https://ajkdblog.org/2019/11/20/kidneywk-2019-intermittent-fasting-and-kidney-disease/

Is Turmeric Bad for Your Kidneys? - https://www.livestrong.com/article/480218-is-turmeric-bad-for-your-kidneys/

Alcohol Consumption and the Risk of Renal Dysfunction in Apparently Healthy Men - 
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/1152793

Chronic Kidney Disease, Fluid Overload and Diuretics: A Complicated Triangle - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4956320/#pone.0159335.ref005

Drinking Alcohol Affects Your Kidneys - https://www.kidney.org/news/kidneyCare/winter10/AlcoholAffects

What Do High Creatinine Levels Mean? - https://www.freseniuskidneycare.com/thrive-central/what-are-high-creatinine-levels

Are oats/oatmeal good or bad for kidney disease? - https://www.dharmakidney.com/oats-oatmeal-good-bad-kidney-disease/

Fasting the month of Ramadan by Muslims: could it be injurious to their kidneys? - https://pubmed.ncbi.nlm.nih.gov/17679744

Effects of Ramadan fasting on moderate to severe chronic kidney disease. A prospective observational study - https://pubmed.ncbi.nlm.nih.gov/28042630

Effects of fasting during Ramadan on renal function of patients with chronic kidney disease - https://pubmed.ncbi.nlm.nih.gov/25758882

Fasting during the month of Ramadan among patients with chronic kidney disease: renal and cardiovascular outcomes - https://pubmed.ncbi.nlm.nih.gov/25349694

Artifactual elevation of serum creatinine level due to fasting- https://pubmed.ncbi.nlm.nih.gov/6466015/