Additionally, Dr. Dadhania, who is also an associate professor of medicine at Weill Cornell Medicine, shares symptoms of poor kidney function and what can be done to manage them.
What do the kidneys do?
Dr. Dadhania: The kidneys remove waste through a filtering process, and this process also removes extra fluid from our blood to make urine. Kidneys also work to maintain a healthy balance of water, salts, and minerals such as sodium, potassium, calcium, and magnesium.
Another function they perform is making hormones that control our blood pressure, as well as produce erythropoietin, a type of hormone that manages hemoglobin, or red blood cells. Kidneys also synthesize active vitamin D to keep our bones healthy.
While most people are born with two kidneys, a person can live a normal and long life with only one healthy kidney.
How do the kidneys work?
Think of your kidneys as a collection of strainers with very fine pores, working together to filter your entire blood volume 60 times per day. Each kidney has approximately 1 million nephrons, which hold a filtering unit called the glomerulus, where the blood is filtered, and a urine collection unit called the tubule, where the toxins are concentrated, and mineral and water balance is achieved.
Waste products produced from food and drug metabolism, as well as normal tissue function and extra fluid that the body does not need, are excreted as urine. The urine from all the tubules comes together and passes through a tube called the ureter, which transports the urine to the bladder.
What happens when the kidneys are not functioning normally?
The body is not able to remove the waste and excess salt and fluid from your body if your kidneys are not working well.
If your kidneys are injured, you may feel weak, you may retain more fluid, and your blood pressure could go up. Depending on where the injury is, good protein can also spill into the urine, making it look foamier. Over time, your urine volume may go down.
What are some symptoms of poor kidney function?
Many times, early kidney injury can be silent. Your urine output can be normal even if you have a kidney injury. It is important to have an annual checkup with your doctor for any early signs of poor kidney function, especially if you have medical conditions like high blood pressure or diabetes.
Some people present with acute kidney injury and may experience headaches, an abrupt rise in blood pressure, blood in the urine, and/or foamy urine.
When enough kidney damage has occurred, one may start to develop symptoms such as tiredness, loss of appetite, nausea, vomiting, tremors, swelling, and decreased exercise tolerance.
What are some common kidney issues?
Two common kidney issues that are easily treated are urinary tract infections and kidney stones. With urinary tract infections, a person may feel burning and have an increased frequency of urination. If this happens, you want to see a doctor and get treatment so that the infection does not spread from the bladder to the kidneys, which would require hospitalization and intravenous antibiotics. With recurrent urinary tract infections, the kidneys can become damaged over time.
With kidney stones, the common presentation is discomfort or pain radiating from the back to the groin. This may also be associated with blood in the urine. Some people may only experience a kidney stone once in their lives, while others may have repeated episodes. If you do develop a kidney stone, it is important to see a kidney specialist who can evaluate you for any genetic disorders or other medical conditions that can predispose you to repeat episodes. Depending on the type of stone, the nephrologist may suggest treatments and dietary changes to avoid future episodes.
Keeping yourself well hydrated and emptying your bladder frequently are good, healthy habits to avoid these conditions.