Normal Kidney Ultrasound Size: A Guide for Adults

Kidney health, often assessed through imaging techniques like ultrasound, plays a crucial role in overall well-being; therefore, understanding what constitutes normal kidney ultrasound size is essential for diagnostic accuracy. The Society of Radiologists in Ultrasound provides guidelines that help standardize measurement protocols for sonographers performing these evaluations. Factors such as patient age and body mass index (BMI) can influence kidney dimensions, impacting the interpretation of ultrasound results. Advanced ultrasound technology, including Doppler imaging, enhances the ability to assess kidney structure and function, refining the determination of normal kidney ultrasound size in adults and aiding in the identification of potential abnormalities.

Unveiling the Significance of Kidney Size in Ultrasound Imaging

Kidney ultrasound stands as a cornerstone in modern medical diagnostics, offering a non-invasive window into the intricate world of renal health. This imaging technique harnesses the power of sound waves to create detailed visualizations of the kidneys, providing invaluable information without the need for invasive procedures.

Defining Kidney Ultrasound

At its core, kidney ultrasound, also known as renal ultrasonography, is a diagnostic imaging modality that employs high-frequency sound waves to generate real-time images of the kidneys. Unlike X-rays or CT scans, ultrasound does not involve ionizing radiation, making it a safer option, particularly for pregnant women and children.

The procedure is performed by a trained sonographer who applies a transducer, a handheld device that emits and receives sound waves, to the abdomen or flank area.

The reflected sound waves are then processed by a computer to form images that reveal the size, shape, and structure of the kidneys.

Kidney Size: A Crucial Indicator of Health

Assessing kidney size during an ultrasound examination is paramount for several reasons. Kidney size serves as a vital indicator of overall renal health, providing crucial clues about potential underlying conditions.

Significant deviations from the normal kidney size range can signal various pathologies, including chronic kidney disease (CKD), acute kidney injury (AKI), hydronephrosis, or even the presence of tumors.

Monitoring kidney size over time can also help track the progression of kidney disease and evaluate the effectiveness of treatment interventions.

Interpreting Ultrasound-Derived Kidney Size Measurements: Setting the Scope

This discussion aims to equip readers with a foundational understanding of interpreting kidney size measurements obtained through ultrasound.

We will focus on elucidating the significance of specific measurements, such as kidney length, width, and cortical thickness, and how these values relate to normal ranges and potential abnormalities.

By demystifying the language of ultrasound reports, we empower individuals to engage more effectively in discussions with their healthcare providers and make informed decisions about their renal health.

The Collaborative Team: Medical Professionals Involved in Kidney Ultrasound Interpretation

The journey of a kidney ultrasound, from its initial order to the final interpretation, involves a diverse team of medical professionals. Each member contributes unique expertise, ensuring a comprehensive evaluation of kidney size and overall renal health. Understanding the roles of these professionals is crucial for patients seeking clarity and informed decision-making in their healthcare journey.

The Key Players in Kidney Ultrasound Interpretation

Several medical professionals play critical roles in the kidney ultrasound process. These include radiologists, sonographers, nephrologists, urologists, and primary care physicians (PCPs). Their collaborative efforts are essential for accurate diagnosis and effective management of kidney-related conditions.

Radiologist: The Imaging Expert

The radiologist is a physician specializing in interpreting medical images, including those from kidney ultrasounds.

After the ultrasound is performed, the radiologist meticulously reviews the images, analyzing the size, shape, and structure of the kidneys.

They identify any abnormalities, such as cysts, tumors, or signs of hydronephrosis.

The radiologist then prepares a detailed report summarizing the findings, which is sent to the ordering physician.

This report is a critical component in the diagnostic process, providing valuable insights into the patient's renal health.

Sonographer: The Imaging Technician

The sonographer, also known as an ultrasound technician, is a trained healthcare professional who performs the kidney ultrasound examination.

Using specialized equipment, they skillfully acquire real-time images of the kidneys, ensuring optimal visualization of the organs.

Their expertise in anatomy and ultrasound physics is vital for capturing high-quality images that accurately represent the kidneys.

The sonographer's role extends beyond image acquisition; they also communicate with patients, explaining the procedure and addressing any concerns.

Nephrologist: The Kidney Specialist

A nephrologist is a physician specializing in the diagnosis and treatment of kidney diseases. They often order or review kidney ultrasound results, particularly when there is a suspicion of kidney dysfunction or disease.

With their in-depth knowledge of renal physiology and pathology, nephrologists can provide expert interpretation of ultrasound findings in the context of a patient's overall clinical picture.

They correlate the imaging results with laboratory data, such as GFR and creatinine levels, to formulate a comprehensive diagnosis and treatment plan.

Urologist: The Urinary Tract Specialist

Urologists specialize in the diagnosis and treatment of conditions affecting the urinary tract, including the kidneys, bladder, and ureters.

They may order or review kidney ultrasounds to evaluate structural abnormalities, such as kidney stones or obstructions.

Urologists are particularly involved in cases of hydronephrosis, where the kidneys become swollen due to a blockage in the urinary tract.

Their surgical expertise allows them to address anatomical issues that may be contributing to kidney problems.

Primary Care Physician (PCP): The Initial Point of Contact

The primary care physician (PCP) often serves as the initial point of contact for patients with kidney-related concerns.

Based on a patient's symptoms, medical history, and physical examination, the PCP may order a kidney ultrasound to investigate potential problems.

While PCPs may not have the same level of specialized knowledge as nephrologists or urologists, they play a crucial role in identifying early signs of kidney disease and coordinating further evaluation and management.

They also help patients understand the ultrasound results and make informed decisions about their care.

The Importance of Collaboration

The collaborative effort of these medical professionals ensures that kidney ultrasound results are interpreted accurately and effectively. By combining their unique expertise, they can provide patients with the best possible care, from initial diagnosis to long-term management of kidney conditions.

Kidney Anatomy 101: Understanding the Structures Measured in Ultrasound

Before delving into the nuances of kidney size interpretation, it's crucial to establish a foundational understanding of kidney anatomy. The kidney is a complex organ, and ultrasound measurements focus on specific structures that provide valuable insights into its overall health. Familiarity with these structures is key to appreciating the significance of ultrasound findings.

Essential Kidney Structures and Their Relevance

Kidney ultrasounds provide a detailed view of several key structures. These include the kidney itself, the renal cortex, the renal medulla, and the renal pelvis. Each plays a unique role in kidney function and contributes to the overall assessment of renal health.

The Kidney: The Foundation of Renal Health

The kidney, bean-shaped and essential, acts as the body's filtration system. It removes waste, regulates fluid balance, and maintains electrolyte levels.

Ultrasound evaluates its overall size and shape. Significant deviations can indicate underlying conditions.

Renal Cortex: The Kidney's Outer Layer

The renal cortex is the outer layer of the kidney, containing the glomeruli and tubules responsible for filtration. Its appearance on ultrasound, including its thickness and echogenicity (brightness), is carefully examined.

Changes in the cortex can suggest various kidney diseases, such as chronic kidney disease or acute kidney injury.

Renal Medulla: The Kidney's Inner Layer

The renal medulla is the inner layer of the kidney, containing the renal pyramids. These structures play a crucial role in concentrating urine.

On ultrasound, the medulla's appearance is assessed for any abnormalities, such as swelling or scarring. These abnormalities would impact kidney function.

Renal Pelvis: The Gateway to the Ureter

The renal pelvis is a funnel-shaped structure that collects urine from the kidney and directs it into the ureter. It is particularly important in cases of hydronephrosis.

Hydronephrosis is where the kidney becomes swollen due to a blockage of urine flow. Ultrasound can detect dilation of the renal pelvis, indicating obstruction or other urinary issues.

Longitudinal Length: A Primary Measurement in Ultrasound

A critical measurement obtained during kidney ultrasound is the longitudinal length of the kidney. This measurement, taken along the longest axis of the kidney, is a key indicator of overall kidney size.

It's compared against established normal ranges, with variations potentially signaling underlying kidney pathology. It helps determine if there are serious issues.

Understanding these basic anatomical structures and their relevance in ultrasound imaging is essential for interpreting kidney size measurements. It contributes to a more comprehensive assessment of renal health.

Physiological Context: Connecting Kidney Size with Function

Kidney size, as assessed through ultrasound, is just one piece of the puzzle when evaluating overall kidney health. Understanding the physiological context—how kidney size relates to kidney function—is crucial for a comprehensive assessment. Several key parameters, including Glomerular Filtration Rate (GFR), creatinine levels, and Blood Urea Nitrogen (BUN) levels, provide valuable insights into renal function and its correlation with kidney size.

These parameters, when considered alongside ultrasound findings, paint a more complete picture of kidney health, helping clinicians distinguish between normal variations and potential pathological conditions. This section explores the interplay between kidney size and these essential markers of renal function.

Glomerular Filtration Rate (GFR): A Key Indicator of Kidney Function

The Glomerular Filtration Rate (GFR) is arguably the most important measure of kidney function. It represents the volume of fluid filtered by the glomeruli (the filtering units of the kidneys) per unit of time, typically expressed in milliliters per minute per 1.73 m² of body surface area.

A normal GFR indicates that the kidneys are effectively filtering waste products from the blood. A reduced GFR, conversely, suggests impaired kidney function. In general, a healthy GFR is usually 90 or above.

The correlation between GFR and kidney size isn't always straightforward. In cases of chronic kidney disease (CKD), a gradual decline in GFR is often accompanied by a decrease in kidney size, as the functional tissue atrophies over time. However, in early stages of kidney disease, or in conditions like diabetic nephropathy, kidney size might initially increase due to compensatory mechanisms, even as GFR declines.

GFR and Kidney Size Discrepancies

It's important to note that a normal kidney size on ultrasound does not always guarantee a normal GFR. Some individuals may have kidneys within the normal size range but still exhibit reduced GFR, indicating functional impairment despite seemingly normal anatomy. Conversely, enlarged kidneys, as seen in polycystic kidney disease (PKD), may initially maintain a relatively normal GFR, only to decline as the cysts progressively compromise renal function.

Therefore, GFR testing is essential, irrespective of kidney size findings on ultrasound, to accurately assess kidney function and detect early signs of kidney disease.

Creatinine: A Waste Product Reflecting Kidney Function

Creatinine is a waste product generated from muscle metabolism. It is filtered by the kidneys and excreted in urine. Serum creatinine levels, measured in milligrams per deciliter (mg/dL), provide an indirect assessment of kidney function.

Elevated creatinine levels typically indicate impaired kidney function, as the kidneys are unable to efficiently remove creatinine from the blood. Normal creatinine ranges vary slightly depending on age, sex, and muscle mass, but generally fall between 0.6 to 1.2 mg/dL for adult males and 0.5 to 1.1 mg/dL for adult females.

Similar to GFR, creatinine levels must be interpreted in conjunction with kidney size measurements. In CKD, elevated creatinine levels often correlate with decreased kidney size. However, acute kidney injury (AKI) may present with normal or even enlarged kidneys, alongside rapidly rising creatinine levels. A normal size can also indicate early or compensated stages of kidney disease.

Blood Urea Nitrogen (BUN): Another Key Indicator of Kidney Function

Blood Urea Nitrogen (BUN) is another waste product, formed in the liver as a byproduct of protein metabolism. Like creatinine, BUN is filtered by the kidneys and excreted in urine. Elevated BUN levels, measured in milligrams per deciliter (mg/dL), can indicate impaired kidney function.

Normal BUN ranges typically fall between 7 to 20 mg/dL. However, BUN levels can be influenced by factors other than kidney function, such as diet (particularly protein intake), hydration status, and certain medications.

While BUN is less specific than creatinine for assessing kidney function, it can provide additional context when interpreted alongside kidney size and other parameters. A high BUN-to-creatinine ratio, for example, may suggest dehydration or decreased blood flow to the kidneys, while simultaneously assessing the kidney size on ultrasound.

Integrating Kidney Size with Physiological Parameters

In conclusion, while kidney size, as measured by ultrasound, provides valuable anatomical information, it's crucial to interpret these findings within the physiological context of kidney function. GFR, creatinine, and BUN levels offer essential insights into the kidney's ability to filter waste and maintain fluid balance.

By integrating kidney size measurements with these functional parameters, clinicians can achieve a more comprehensive and accurate assessment of kidney health, leading to more informed diagnoses and treatment decisions. Ignoring these parameters can lead to misdiagnosis.

Medical Conditions and Kidney Size: What the Measurements Can Tell Us

Kidney size, as observed via ultrasound, serves as a significant indicator in the diagnosis and monitoring of various renal pathologies. The following section delineates how different medical conditions manifest in ultrasound findings, affecting kidney size and overall morphology. Understanding these correlations is vital for accurate diagnosis and treatment planning.

Hydronephrosis: Understanding the Impact on Kidney Size and Ultrasound Findings

Hydronephrosis refers to the swelling of a kidney due to the buildup of urine. This occurs when urine cannot drain properly from the kidney to the bladder.

On ultrasound, hydronephrosis typically presents as a distention of the renal pelvis and calyces, often leading to an overall increase in kidney size, particularly in the early stages. The severity of hydronephrosis is graded based on the degree of dilation observed.

Severe cases can cause significant parenchymal thinning as the pressure from the retained urine compresses the functional kidney tissue. Early detection via ultrasound is crucial to prevent irreversible damage.

Chronic Kidney Disease (CKD): Linking Reduced Kidney Size to Disease Progression

In contrast to hydronephrosis, Chronic Kidney Disease (CKD) generally leads to a decrease in kidney size. This reduction is a result of long-term damage and scarring (fibrosis), causing the functional tissue to atrophy.

Ultrasound imaging in CKD often reveals smaller-than-normal kidneys with increased echogenicity, indicating fibrosis. The extent of size reduction typically correlates with the severity and duration of the disease.

However, it's important to note that some conditions, such as diabetic nephropathy, can present with normal or even enlarged kidneys early in the disease process, despite underlying CKD.

Acute Kidney Injury (AKI): Identifying Potential Changes in Kidney Size

Acute Kidney Injury (AKI) involves a sudden loss of kidney function. Ultrasound findings in AKI can be variable, depending on the underlying cause.

In some cases, kidneys may appear normal in size, particularly in the early stages or when AKI is caused by factors like medication toxicity or acute tubular necrosis.

Conversely, conditions like acute obstruction or glomerulonephritis can lead to kidney enlargement due to inflammation or fluid accumulation. Therefore, correlating ultrasound findings with clinical history and laboratory data is essential in diagnosing AKI.

Polycystic Kidney Disease (PKD): Diagnosing Enlarged Kidneys with Multiple Cysts

Polycystic Kidney Disease (PKD) is a genetic disorder characterized by the development of numerous cysts within the kidneys. These cysts progressively enlarge over time, leading to a significant increase in kidney size.

On ultrasound, PKD is characterized by bilateral enlarged kidneys with multiple cysts of varying sizes. The presence and number of cysts increase with age. This pathological growth compresses and replaces normal kidney tissue, eventually leading to kidney failure.

Diabetic Nephropathy: Understanding Kidney Damage Caused by Diabetes

Diabetic nephropathy, a common complication of diabetes, can initially cause kidney enlargement due to glomerular hypertrophy.

However, as the disease progresses, fibrosis and scarring develop, leading to a gradual decrease in kidney size.

Early ultrasound findings may reveal normal or even larger kidneys, while later stages are characterized by smaller, more echogenic kidneys, similar to other forms of CKD. The presence of proteinuria and declining GFR are critical indicators alongside the ultrasound findings.

Hypertensive Nephropathy: The Impact of High Blood Pressure on Kidney Health

Hypertensive nephropathy results from long-standing high blood pressure damaging the kidneys. Similar to diabetic nephropathy, the initial stages may involve mild kidney enlargement, but chronic hypertension typically leads to renal atrophy and decreased kidney size.

Ultrasound findings may show smaller kidneys with increased cortical echogenicity. The presence of other signs of end-organ damage, such as left ventricular hypertrophy, can further support the diagnosis.

Renal Artery Stenosis: Assessing the Impact of Artery Narrowing on Kidney Size

Renal artery stenosis involves the narrowing of one or both renal arteries, reducing blood flow to the kidneys. This can lead to ischemic atrophy, resulting in a decrease in kidney size on the affected side.

Ultrasound, particularly with Doppler assessment, can help identify renal artery stenosis by measuring blood flow velocities. Significant size asymmetry between the two kidneys can raise suspicion for renal artery stenosis.

Renal Insufficiency: Reduced Kidney Function and Ultrasound Correlation

Renal insufficiency is a broad term referring to reduced kidney function, often associated with various underlying kidney diseases. While renal insufficiency often accompanies chronically small kidneys, the key indicator remains impaired kidney function, as determined by GFR and creatinine levels.

Ultrasound can identify associated morphological changes like reduced cortical thickness, increased echogenicity, or presence of cysts or masses. However, normal kidney size does not exclude the presence of renal insufficiency, reinforcing the need for comprehensive evaluation.

Beyond Ultrasound: Complementary Imaging Modalities for Comprehensive Kidney Assessment

While kidney ultrasound provides a valuable initial assessment of renal morphology, it's often part of a larger diagnostic workup. Other imaging modalities offer complementary information, enhancing the accuracy and comprehensiveness of kidney evaluations. These tools provide insights into renal blood flow, detailed anatomical structures, and functional characteristics, enabling a more nuanced understanding of kidney health.

The Role of Kidney Ultrasound

Ultrasound serves as the primary imaging modality for initial kidney assessment due to its non-invasive nature, affordability, and lack of ionizing radiation.

It excels at visualizing kidney size, detecting hydronephrosis, identifying cysts and masses, and assessing the overall structure of the renal parenchyma.

During a kidney ultrasound, a sonographer applies a transducer to the abdomen or flank area to generate real-time images of the kidneys.

Measurements of kidney length, width, and cortical thickness are taken, and any abnormalities are documented.

However, ultrasound has limitations. It can be challenging to visualize small lesions or assess renal blood flow adequately. In such cases, additional imaging modalities become essential.

Doppler Ultrasound: Assessing Renal Blood Flow Dynamics

Doppler ultrasound is a specialized technique that assesses blood flow within the renal arteries and veins.

By measuring the velocity and direction of blood flow, Doppler ultrasound can detect renal artery stenosis (narrowing), a condition that can lead to hypertension and kidney damage.

This technique is particularly useful in patients with suspected renovascular disease or in those with uncontrolled hypertension despite medical management.

Doppler ultrasound can also evaluate the resistive index (RI), a measure of vascular resistance within the kidney, which can provide insights into renal parenchymal disease.

CT Scan (Computed Tomography): Providing Detailed Anatomical Views

Computed Tomography (CT) scanning offers highly detailed anatomical images of the kidneys, providing superior visualization of small lesions, stones, and vascular abnormalities compared to ultrasound.

CT scans use X-rays to create cross-sectional images of the kidneys, which can be reconstructed into three-dimensional images.

CT is particularly useful in evaluating complex kidney stones, renal masses, and suspected infections such as pyelonephritis.

However, CT scans involve exposure to ionizing radiation, and contrast agents used to enhance the images can be nephrotoxic (harmful to the kidneys) in some individuals. Therefore, the benefits of CT scanning must be carefully weighed against the risks.

MRI (Magnetic Resonance Imaging): Advanced Imaging for Soft Tissue Assessment

Magnetic Resonance Imaging (MRI) provides excellent soft tissue contrast and does not involve ionizing radiation (unless contrast is used).

MRI is particularly useful for evaluating renal masses, staging renal cell carcinoma, and assessing vascular abnormalities such as renal vein thrombosis.

MRI can also be used to assess kidney function using techniques such as diffusion-weighted imaging and blood oxygen level-dependent (BOLD) imaging.

Gadolinium-based contrast agents, which enhance MRI images, have been associated with nephrogenic systemic fibrosis (NSF) in patients with severe kidney disease, limiting their use in this population. However, newer contrast agents with lower risk are available.

Deciphering the Numbers: Understanding Kidney Size Measurements

The language of kidney ultrasound reports can seem cryptic, filled with numerical values and technical terms. Understanding these numbers is crucial for both medical professionals and patients seeking to grasp the significance of their ultrasound findings. This section will demystify the measurements used in kidney ultrasound, focusing on units and interpretation within the context of normal ranges.

Units of Measurement: Centimeters and Millimeters

Kidney size, as assessed by ultrasound, is primarily documented using two units: centimeters (cm) and millimeters (mm). Understanding the context in which each unit is used is key to accurate interpretation.

Centimeters (cm): The Standard for Kidney Length

Centimeters (cm) are the standard unit for expressing the overall length of the kidney. This measurement provides a general indication of kidney size and is a fundamental component of the ultrasound report. A typical adult kidney measures approximately 9-12 cm in length. This value can be easily compared to reference ranges.

Millimeters (mm): Detecting Subtle Variations

Millimeters (mm) come into play when describing smaller structures or subtle variations within the kidney. For instance, the size of a small cyst or the thickness of the renal cortex might be documented in millimeters. The use of millimeters allows for greater precision when assessing details that might be missed if only centimeters were used.

Navigating the Normal Range

Ultrasound reports provide numerical measurements, but these numbers only gain meaning when compared to established normal ranges. It is vital to understand that “normal” is not a single value, but rather a spectrum.

Why a Range, Not a Number?

Kidney size varies based on several factors, including age, sex, body size, and ethnicity. Therefore, rather than a fixed number, a normal range accounts for these individual variations. This range provides a more accurate framework for evaluating whether a kidney's size falls within expected limits.

Interpreting Ultrasound Reports

Ultrasound reports typically include the measured dimensions of each kidney alongside the reference range. If a kidney's length falls outside this range, it may indicate an underlying condition. However, it's crucial to avoid drawing conclusions based solely on size. The radiologist or interpreting physician will consider the measurements in conjunction with other findings. They will assess the patient’s clinical history and potentially request additional tests to arrive at an accurate diagnosis.

The Significance of Context

It is worth noting that slight deviations from the normal range do not always indicate a serious problem. Individual anatomical variations exist, and some people naturally have kidneys that are slightly larger or smaller than average. The overall clinical picture is essential, which includes a patient's symptoms, medical history, and other diagnostic test results.

In conclusion, understanding the units of measurement used in kidney ultrasound and the importance of comparing those measurements to normal ranges is crucial for interpreting ultrasound reports. However, remember that these measurements are just one piece of the puzzle. A comprehensive evaluation by a qualified medical professional is always necessary to determine the true significance of the findings.

Factors Influencing Kidney Size: Age and Other Considerations

While kidney ultrasound provides a snapshot of kidney size at a specific point in time, it's crucial to understand that this size isn't static. Several factors can influence kidney dimensions, with age being a particularly significant one. Recognizing these influences allows for a more nuanced and accurate interpretation of ultrasound findings.

The Impact of Aging on Kidney Size

As we age, the kidneys, like many other organs, undergo natural changes that can affect their size and overall function. A key consideration is the gradual decline in kidney mass that typically begins after the age of 50.

This decline is primarily due to a reduction in the number and size of nephrons, the functional units of the kidney responsible for filtering blood and producing urine. The result is often a decrease in kidney length and volume observed on ultrasound.

Age-Related Reduction in Kidney Size: What to Expect

Studies have shown that kidney length tends to decrease by approximately 0.5 to 1 cm per decade after the age of 50. This means that a 70-year-old individual might have kidneys that are noticeably smaller than those of a younger adult.

While a reduction in size is generally expected with age, it's important to distinguish between normal age-related changes and those indicative of underlying kidney disease. A significant decrease in kidney size, especially when accompanied by other clinical signs or symptoms, warrants further investigation.

Beyond Age: Other Factors at Play

While age is a primary determinant, other factors can also influence kidney size. These include:

• Body Size and Composition: Larger individuals tend to have larger kidneys.

• Sex: Men typically have slightly larger kidneys than women.

• Ethnicity: Some studies suggest that kidney size may vary slightly among different ethnic groups.

• Presence of Solitary Kidney: Individuals born with a single kidney, or who have had one removed, will naturally have a larger remaining kidney, as it compensates for the missing one.

• Underlying Medical Conditions: Conditions like diabetes and hypertension, while generally leading to kidney damage over time, might initially cause an increase in kidney size before a decrease.

Considerations for Accurate Interpretation

To accurately interpret kidney size measurements, it's essential to consider all these influencing factors. A radiologist will take into account the patient's age, sex, body size, and medical history when evaluating the ultrasound findings.

Furthermore, comparing current ultrasound measurements to previous ones, if available, can help determine whether any size changes are gradual and consistent with normal aging or represent a more significant deviation from the patient's baseline.

In conclusion, while ultrasound provides valuable information about kidney size, interpreting these measurements requires careful consideration of various influencing factors, particularly age. By accounting for these factors, medical professionals can make more accurate diagnoses and provide appropriate guidance for patients.

So, there you have it! Hopefully, this guide sheds some light on what's considered a normal kidney ultrasound size in adults. Remember, if you have any concerns about your kidney health, always consult with your doctor – they're the best equipped to interpret your specific results and guide you toward the right course of action.