Low or high creatinine: What does it mean and what are its causes

Creatinine is a compound found in the blood and is generated from creatine metabolism, a substance produced in the muscles. Its elimination is done through the kidneys, so their blood levels can be an important indicator of renal function and muscle state.

When a blood test reveals Low creatinine levelsit can be a sign of a reduction in muscle mass, liver diseases or a poor protein diet. On the other hand, the High creatinine It is usually related to kidney problems or dehydration.

Therefore, measuring creatinine in a blood test gives us clues both about the functioning of the kidneys and on the state of the muscles.

We want to thank the collaboration and medical review in the elaboration of this article to the Dr. Antonio Moreno Salazar, nephrologist at the Viamed Bahía de Cádiz hospitalwhose experience has been fundamental to guarantee the accuracy of information.

What is creatinine and what is its function?

Creatinine is a waste product which is generated when the muscles use creatine to obtain energy. Being a compound that the body produces constantly, its concentration in the blood remains stable and depends mainly on muscle mass and renal function.

The kidneys are responsible for filtering creatinine and eliminating it through urine. Therefore, a Increase or decrease in blood creatinine It may indicate changes in renal function or muscle mass.

Normal blood creatinine values

Normal creatinine values ​​can vary according to age, sex and muscle mass. In general, normal ranges (although they may vary according to the laboratory) are:

• Men:7 to 1.3 mg/dl
• Women:6 to 1.1 mg/dl
• Children:2 to 1.0 mg/dl

Values ​​outside this range may require a medical evaluation to determine its cause.

Low creatinine: What does it mean and what are its causes?

When blood creatinine is Below the normal rangeit can be a reflection of a reduction in muscle mass or certain metabolic disorders, although it is not usually a serious problem alone.

Possible causes of low creatinine

1. Loss of muscle mass: Sarcopenia (loss of muscle with age) or lack of prolonged physical activity can reduce creatinine levels.
2. Liver diseases: The liver plays a key role in creatine production, so diseases such as cirrhosis can affect their levels.
3. Low protein diet: Insufficient protein consumption may reduce creatinine production.
4. Pregnancy: During pregnancy, creatinine can decrease due to the increase in blood volume and the highest renal filtration.
5. Excessive fluid consumption: Drinking too much water can dilute the concentration of creatinine in blood.
6. Neuromuscular disorders: Diseases such as muscle dystrophy can cause lower creatinine production.

Low creatinine symptoms

In many cases, low creatinine does not cause obvious symptoms. However, if it is related to an underlying condition, signs such as:

• Fatigue and muscle weakness.
• Weight loss without apparent cause.
• Difficulty in making physical efforts or tiredness.

High creatinine: What does it mean and what are its causes?

When the kidneys do not work well, creatinine tends to climb because it is not eliminated correctly. But it does not always mean a serious illness, it can also climb temporarily.

Possible causes of high creatinine

1. Kidney diseases: Renal failure is one of the main causes of high creatinine, since the kidneys do not correctly filter waste.
2. Dehydration: When the body loses fluids, blood creatinine concentration can increase.
3. Excessive protein consumption: Diets rich in red meat can temporarily raise their levels.
4. Intense physical exercise, musculation or the use of creatine supplements can temporarily increase levels
5. Severe infections or fever: Metabolic stress can increase creatinine production.
6. Use of certain medications: Some antibiotics, anti -inflammatories or drugs for blood pressure can affect creatinine values.

High creatinine symptoms

• Swelling in legs and ankles.
• Persistent fatigue
• Difficulty urinating or changes in the amount of urine.
• Nausea or loss of appetite.

How are abnormal creatinine levels diagnosed?

To evaluate creatinine levels, the doctor can request:

• Blood creatinine analysis: The amount of creatinine present in the bloodstream is measured.
• Creatinine in urine: It allows to evaluate how much the body is eliminating.
• Glomerular filtration index (IFG): It is used to calculate renal function and detect kidney diseases in its early stages.

If the results show abnormal levels, additional tests can be performed to identify the cause and determine the most appropriate treatment.

Treatments and recommendations

Low creatinine treatment

If the low creatinine is due to a loss of muscle mass or a poor diet, measures such as:

• Increase protein intake: Include lean meats, eggs, dairy and legumes in food.
• Perform force exercise: Resistance training help improve muscle mass.
• Treat liver diseases: If the cause is a liver condition, specific medical treatment will be necessary.

High creatinine treatment

When high creatinine is related to renal function or metabolism, it is important:

• Maintain adequate hydration: Drink enough water to avoid creatinine concentration.
• Control protein consumption: In some cases, reducing red meat intake and creatine supplements can be beneficial.
• Follow treatment for kidney diseases: If high creatinine is a sign of renal failure, the doctor will indicate the proper treatment.

Creatinine is an important marker to evaluate renal and muscular health. Both low and high levels can be alert signals about the state of the body. If a blood test shows abnormal values, it is essential to go to a specialist to determine the cause and follow the proper treatment.

If you need a medical evaluation or a blood test to know your creatinine levels, in Viamed Salud We have specialists who can help you identify the cause and recommend the most appropriate treatment.

In addition, if you are performing intense physical exercise, musculation or supplementation with proteins or creatine, it would be convenient to perform medical control with the specialist.

Agenda your appointment today and take care of your health.