Creatinine is a waste product made when your muscles use creatine for energy. Healthy kidneys filter it out of the blood and into urine. When creatinine builds up, it usually means the kidneys are not filtering as well as they should, though dehydration, a high-protein diet and intense exercise can also push it up temporarily. This guide explains the normal range, what a high result really means, and the steps that genuinely help.
Normal creatinine levels
Reference ranges vary slightly between laboratories. These are typical adult values:
| Group | Typical normal range |
|---|---|
| Adult men | 0.7-1.3 mg/dL (62-115 micromol/L) |
| Adult women | 0.6-1.1 mg/dL (53-97 micromol/L) |
| Teenagers | 0.5-1.0 mg/dL |
| Children | 0.3-0.7 mg/dL |
Men usually have higher creatinine because they tend to have more muscle mass. A muscular athlete can sit at 1.4 mg/dL and still have perfectly healthy kidneys. This is why a single creatinine number should never be read in isolation.
The number that matters more: eGFR
Laboratories usually report an estimated glomerular filtration rate (eGFR) alongside creatinine. eGFR estimates how much blood the kidneys filter per minute, adjusted for age and sex. It is a better measure of kidney function than creatinine alone.
- eGFR 90 or above: normal filtration (unless there is other evidence of kidney damage)
- eGFR 60-89: mildly reduced; often normal with age
- eGFR 45-59: moderately reduced
- eGFR 30-44: moderately to severely reduced
- eGFR below 30: severely reduced; specialist care needed
A rising creatinine with a falling eGFR over repeated tests is more meaningful than either value on its own.
Common causes of high creatinine
Temporary and lifestyle causes
- Dehydration: less water means more concentrated blood and a higher reading.
- High-protein diet: large amounts of meat, fish or protein powder increase creatinine production.
- Intense exercise: heavy training, especially weightlifting, raises it for a day or two.
- Creatine supplements: directly increase creatinine levels and can look like kidney disease on a test.
- Recent cooked-meat meal: can raise creatinine slightly before a blood test.
Medical causes
- Chronic kidney disease: diabetes and high blood pressure are the two biggest causes worldwide.
- Acute kidney injury: a sudden drop in kidney function from infection, dehydration, surgery or medication.
- Urinary blockage: an enlarged prostate, kidney stones or a tumour can back up urine.
- Medicines: NSAIDs such as ibuprofen and diclofenac, some antibiotics, contrast dye and certain blood pressure drugs can raise creatinine.
- Heavy metal or herbal supplement exposure: some unregulated products are toxic to kidneys.
Symptoms of high creatinine
Mildly raised creatinine usually causes no symptoms at all, which is why kidney disease is often called a silent condition. When kidney function drops significantly, you may notice:
- Swelling in the ankles, feet, hands or face
- Foamy or bubbly urine (a sign of protein leakage)
- Passing less urine than usual
- Tiredness, weakness or poor concentration
- Nausea, loss of appetite or a metallic taste
- Itching, muscle cramps or restless legs
- Shortness of breath from fluid build-up
None of these are specific to kidney disease, but a combination plus a high creatinine warrants prompt testing.
How to lower creatinine levels
There is no magic drink or supplement that “flushes” creatinine. The effective approach is to reduce the load on the kidneys and control the conditions that damage them.
1. Stay properly hydrated
Drink enough water that your urine is pale yellow. For most adults that is roughly 2-3 litres a day, more in heat or with exercise. If you have advanced kidney disease or heart failure, your doctor may restrict fluids, so ask before increasing intake. See how much water you should drink a day for a more detailed guide.
2. Control blood pressure and blood sugar
Diabetes and hypertension cause the majority of kidney damage. Keeping HbA1c and blood pressure in target range is the single most effective way to protect kidney function. Many people with diabetes also benefit from specific medicines (SGLT2 inhibitors, ACE inhibitors or ARBs) that slow kidney decline. Start with our guides to type 2 diabetes and high blood pressure.
3. Moderate protein, do not eliminate it
A very high-protein diet increases creatinine. Aim for a moderate intake, roughly 0.8-1.0 g per kg of body weight for most adults, unless a doctor or dietitian advises otherwise. Do not cut protein to near zero; that causes muscle loss without helping the kidneys.
4. Avoid kidney-irritating painkillers
Regular use of NSAIDs (ibuprofen, naproxen, diclofenac) can reduce kidney blood flow. Use paracetamol for routine pain where appropriate, and ask a doctor before long-term NSAID use, especially if you already have kidney disease.
5. Reduce salt and processed food
High sodium raises blood pressure and puts extra strain on the kidneys. Most salt comes from packaged snacks, sauces, pickles and restaurant food rather than the salt shaker.
6. Exercise regularly, but do not overdo it before a test
Moderate exercise improves blood pressure and blood sugar. Avoid heavy training or creatine supplements for at least 48 hours before a kidney blood test, and mention both to your doctor.
7. Stop smoking and limit alcohol
Smoking damages blood vessels throughout the body, including the kidneys. Heavy alcohol use raises blood pressure and can dehydrate you.
8. Review all medicines and supplements
Bring every prescription, over-the-counter drug and herbal product to your doctor. Some common supplements and unregulated “kidney cleanse” products are harmful.
What not to do
- Do not buy “kidney detox” teas or pills. There is no evidence they lower creatinine, and some contain toxins.
- Do not cut out all salt, protein or fluids without medical advice.
- Do not panic over one mildly high reading. Repeat the test, ideally fasting and well hydrated.
- Do not ignore a rising trend across several tests.
When to see a doctor
- Creatinine above the lab’s reference range on two separate tests
- eGFR below 60 on repeated testing
- Protein or blood in your urine
- A rapid rise in creatinine over days or weeks
- Swelling, reduced urine output or unexplained fatigue
- You have diabetes, high blood pressure or a family history of kidney disease
A nephrologist may order a urine albumin-to-creatinine ratio, an ultrasound and further blood tests to find the cause.
Frequently asked questions
Is a creatinine level of 1.5 high?
It is above the typical adult range, but whether it matters depends on your muscle mass, age, sex and eGFR. A muscular man can have 1.5 with normal kidney function. Repeat the test and check eGFR and urine protein before worrying. If you also have joint pain or swelling, read our guide to high uric acid and gout.
Can drinking water lower creatinine?
If you are dehydrated, yes. Rehydration can bring a temporarily raised creatinine back toward normal. If kidney function is genuinely reduced, water alone will not fix it.
Does creatinine fluctuate during the day?
Yes. It is usually higher in the afternoon and after a protein-rich meal or exercise, and lower in the morning. That is why doctors prefer a consistent, fasting sample.
Is creatinine 2.0 dangerous?
It suggests significantly reduced kidney function and should be assessed promptly, especially if it rose quickly. The danger depends on eGFR, symptoms and whether the rise is acute or chronic.
Can high creatinine be reversed?
If the cause is temporary, such as dehydration or a medication, it often returns to normal. Chronic kidney damage cannot usually be reversed, but treatment can slow progression and protect remaining function.
