Kidney Korner: How the Kidneys Filter Blood

Did you know your kidneys filter your blood approximately 35 times per day? Let's learn about the filtering process!

The Process:

1. Blood enters the kidneys through the renal artery.
2. Blood vessels carry the blood to the nephrons to begin the filtering process. 
3. Amino acids, salt, urea, water, and small substances are removed from the blood.
4. Based on what the body needs, some of these substances are reabsorbed back into the blood and the waste, now urine, is left in the nephron.
5. A large vein removes the clean blood to be filtered back into the body.
6. Urine from the nephrons are sent through the ureter to the urinary bladder to be stored then released through urination.

How Dr. Munjal helps:
There are various tests that Dr. Munjal can order to detect how well the kidneys are filtering and functioning. Lab tests like urinalysis, urine protein studies, and basic metabolic/comprehensive metabolic/renal function panels will show the following related to kidney function:

• estimated Glomerular Filtration Rate (eGFR): How much the kidneys are filtering
• Electrolytes: sodium, calcium, potassium, chloride, magnesium, and phosphate 
• Creatinine: waste product
• Blood Urea Nitrogen (BUN): waste product
• Protein urine levels: can indicate damage to the kidneys

Dr. Munjal will review these results at an appointment with the patient, interpret them, and discuss a plan of action to help reduce potential harm or further deterioration. Dr. Munjal may also order imaging tests to determine if there are any blockages in the renal artery or veins or if there is anything that may physically be inhibiting the kidneys from functioning properly. 

Munjal’s Musings:
Think of your kidneys as a coffee filter. It has two jobs: let the coffee through and keep the grounds in. Similarly, kidneys want to get rid of waste, but keep the good things in. To see how well the filter is working we can measure the following:

• We measure the blood level of creatinine, which is a waste product. Low levels means that the kidneys are functioning well. 
• We check protein levels in the urine.  Protein particles are large and should not be spilling through the filter. High protein levels in the urine are indicative of kidney damage.  

Be Proactive:

• Complete lab work for follow-up appointments in a timely manner
• Consult with your physician on preventative care and maintenance
• Follow a renal-friendly diet and maintain adequate hydration

If you have any questions about how your kidneys function, call our office to set up a consultation with Dr. Munjal to empower yourself through education. 

​This website is for informational and educational purposes ONLY. While we strive for accurate, general medical information, this does not replace professional medical advice. Do not rely solely on this information. Please consult with your provider for more information regarding your specific needs. If you are experiencing a medical emergency, please call 9-1-1.

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