What is Considered a Dangerous Bun Creatinine Ratio?
When doctors order a blood test, patients often don’t know what it tests for. The doctor may throw out terms like “BUN” or “creatinine,” and the patient has no clue what they are. However, if the results come back irregular, the patient quickly wants to know what they mean and if they should be concerned.
If the doctor states an individual has a high BUN creatinine ratio, the patient may automatically worry that they are dying. This ratio could indicate they are dehydrated, and the problem can be easily rectified. However, it could also suggest that they have permanent kidney damage, and additional treatment will be needed. Doctors use this ratio to determine whether a patient has blood flow problems or kidney tissue damage. The earlier a problem is caught and treated, the better the outcomes tend to be. What is a dangerous bun creatinine ratio?
What is Considered an Elevated Ratio?
Patients typically don’t know what a normal BUN-to-creatinine ratio is and are completely unaware of what would be considered elevated. Doctors look for a ratio of 10:1 to 20:1 when checking the results. This elevated ratio means the patient needs medical attention, and the underlying cause must be detected. Fortunately, in many cases, an elevated ratio is due to dehydration. It may be that they are taking medication that raises this ratio, or they have a temporary illness. A person should not assume that they have permanent kidney damage when they hear about this elevated ratio. They need to let the doctor do more investigating before worrying.
What Does This Ratio Measure?
The BUN-to-creatinine ratio assesses how well the kidneys are filtering waste products from the blood. Are they doing a good job, or is there a problem that must be addressed? If BUN levels are rising faster than creatinine, doctors know to look for potential problems with blood flow to the kidneys. They may then conduct additional tests to identify the underlying cause and develop a treatment plan. Fortunately, oftentimes, the elevated level can be easily treated.
BUN and creatinine
Once a person knows they don’t need to panic if their levels are high automatically, they want to learn more about what BUN and creatinine are. BUN is blood urea nitrogen. As the name suggests, this number indicates how much nitrogen is in your blood. The liver makes the substance during protein metabolism. The liver is responsible for breaking down proteins from the food the individual consumes.
When the kidneys function correctly, they filter urea from the blood and excrete it through urination. If the kidneys aren’t functioning optimally, the BUN level will rise. Urea is remaining in the blood instead of being removed as it should be.
Creatinine is another waste product. As a person uses their muscles, this product is created. The muscles produce the substance using a protein called creatine, so they have the energy they need to support activity. Creatinine levels typically remain stable. The kidneys filter the substance out regularly. However, if kidney function declines, creatinine begins to accumulate in the blood.
Calculating the Bun/creatinine Ratio
Doctors use a formula to calculate the BUN-to-creatinine ratio. They take the bun level and divide it by the creatinine level to get a figure. These numbers are measured in milligrams per deciliter of blood, and the doctor reviews the ratio to determine whether there is a pattern to investigate.
At times, the numbers rise simultaneously. The ratio remains normal, although each figure is higher than usual. For this reason, doctors look at each figure individually, then at the ratio. Doing so allows them to catch problems early.
When Should Elevated Levels Be Concerning?
The normal BUN-to-creatinine ratio is 10:1 to 20:1. As a person ages, the ratio is typically closer to 20:1 than 10:1. Anything above 20:1 is considered high, and doctors will begin looking for signs of kidney issues. However, the person might be dehydrated or developing health issues. If these issues are treated, the ratio may return to a normal level.
Doctors consider three things when examining this ratio. They’re looking for a high BUN with a normal creatinine, a normal BUN with low creatinine, or a high BUN and high creatinine, with the BUN significantly higher. Anytime this ratio is 50:1 or higher, the individual needs immediate medical attention. When it reaches 100:1, there is a serious kidney issue that must be addressed promptly.
Addressing Elevated Bun-to-Creatinine Ratios
Doctors review these figures and develop a treatment plan based on potential underlying causes. It could be that blood flow to the kidneys has decreased, so they can no longer filter waste products properly. Dehydration is a common cause for this issue, and both figures will increase, but the BUN level will be significantly higher. The kidneys are reabsorbing some urea, but they cannot reabsorb creatinine, which is why the BUN level is much higher.
Cardiovascular and circulatory issues can also lead to increased BUN levels. When the heart is failing, blood flow to the kidneys decreases, and the kidneys must work harder to remove waste products.
Cardiovascular and Circulatory Issues
Heart failure reduces blood flow to the kidneys, leading to increased BUN levels. This condition forces the kidneys to work harder to filter waste products from a reduced blood supply. When a person goes into shock, kidney perfusion decreases, and the BUN-to-creatinine ratio may rapidly rise. Immediate medical attention is needed to prevent permanent kidney damage.
Gastrointestinal Issues
Gastrointestinal issues, often brought on by the individual’s diet, can lead to an elevated BUN-to-creatinine ratio. Bleeding within the gastrointestinal system increases the protein load, and the liver must process this extra protein. As it does so, the BUN and creatinine levels will rise significantly. High-protein diets are known to raise BUN levels in healthy individuals temporarily. Doctors frequently won’t worry about this increase unless they see other risk factors in the patient.
Many other factors can increase the BUN-to-creatinine ratio. A person might be taking medication or undergoing a medical treatment that raises this level, or they may be suffering from progressive kidney disease. High blood pressure and acute kidney issues are other things the doctor will look for when they see an elevated level.
A patient should not be overly concerned if their doctor reports that their BUN-to-creatinine ratio is high after a blood test. Unless this ratio is 50:1 or higher, the doctor will spend time investigating the underlying cause. However, if the ratio reaches 50:1 or higher, the patient needs immediate medical attention. Furthermore, suppose they suffer from extreme fatigue, or have trouble breathing, begin to swell significantly, or are confused. In that case, they need to head straight to the emergency room, as this could indicate their kidneys are failing. Quick action will provide the best outcomes.