Creatinine is a chemical waste molecule that is produced when muscles use creatine (another naturally occurring product in the body) to create energy. About 2% of creatine is converted to creatinie each day. Most of the waste creatinine is expelled from the body in the urine. The creatinine level measured for an individual should be relatively constant over time and should be within a “normal” range. However, you should pay attention to creatinine level that is too high or too low because that could mean there are problems with your kidney.
Why is the creatinine level important? The creatinine level is one of the main indicators of kidney function. If the creatinine level is elevated, your healthcare provider will look for other signs of kidney disease and renal problems.
Normal creatinine levels are measured in milligrams (1 mg=1/1000 of a gram) and deciliters (1 dl=1/10 of a liter). Normal creatinine level ranges will depend on age, gender and other health factors. The “normal” range may also be slightly different depending on the lab where it is measured.
Tests to Measure Kidney Function
If your healthcare provider suspects you may have decreased renal function, she will probably order lab tests that might include blood urea nitrogen (BUN) level, a creatinine level and a BUN/Creatinine ratio. With diminished kidney function, creatinine and BUN levels will both increase.
Causes: High creatinine levels can be caused by anything that decreases the function of the kidneys. There are acute and chronic causes of changes in the creatinine level. Two of the most significant and common causes of chronic kidney disease are diabetes and hypertension. Muscle building can lead to elevated creatinine levels. Chemotherapy drugs are known to cause high creatinine levels. Finally, an individual with a diet high in red meat may have slightly elevated creatinine levels.
Symptoms: Symptoms of kidney disease and elevated creatinine are variable and, in fact, some individuals may not have any symptoms at all. Extreme thirst and tiredness may be early symptoms. Swelling of the extremities and shortness of breath may also be symptoms of a kidney disorder. Mental changes and confusion are usually late symptoms of kidney problems.
Treatments: Treatment of kidney disease as evidenced by a high creatinine level is based on determining the underlying cause and living a generally healthy lifestyle.
Causes: Low creatinine levels are typically caused by muscle wasting diseases, chronic liver disease or the normal aging process. A diet very low in protein and pregnancy in women can result in abnormally low creatinine levels. With a low level, there may be no evident symptoms.
Treatments: There are really no specific treatments for low creatinine levels. If the cause is a muscle wasting disease, all treatments are aimed at treating the disease and not the creatinine level. In these cases, the healthcare provider may prescribe steroid medications to help slow muscle breakdown. Low creatinine levels associated with pregnancy typically resolve when the pregnancy is over. Individuals who do not eat enough quality protein will be advised to increase their intake of protein.