Low levels of creatinine in the urine may point to a kidney disease, certain muscular and neuromuscular disorders, or a blockage in the urinary tract.

Low creatinine levels can be caused by:

- A muscle disease (ex.: muscular dystrophy.)

- A liver disease. Poor liver function interferes with creatine production, which can cause low creatinine.

- Excess water loss. Pregnancy, excess water intake, and certain medications can cause this.

Since the breakdown of muscle tissue produces creatinine, low levels of this chemical waste often occurs in people with low muscle mass. This, however, doesn’t necessarily mean there’s a medical problem.

A reduction in muscle mass is common in older individuals, as most people lose muscle mass as they age. Low muscle mass can also result from malnutrition, or from eating a low-meat or low-protein diet.

Higher levels may mean that you have kidney disease.

Possible causes of a higher creatinine level include:

- kidney damage

- kidney failure

- kidney infection

- decreased blood flow to the kidneys

- dehydration

If you have high creatinine levels, symptoms may include:

- nausea

- vomiting

- fatigue

- changes in urination

- high blood pressure

- chest pains

- muscle cramps

When creatinine begins to accumulate in the body, doctors have to run tests to check for kidney problems.