The kidneys are two bean-shaped organs, each about the size of a fist. They are located one on each side of your spine, just below the rib cage.
Kidney function refers to the vital role that the kidneys play in maintaining the body’s overall health and balance. The kidneys are bean-shaped organs located on either side of the spine, below the ribcage. They perform several essential functions that are critical for maintaining the body’s internal environment. Some of the key functions of the kidneys include:
- Filtration of Blood: The kidneys filter waste products, excess fluids, and electrolytes from the bloodstream to form urine. This process helps remove toxins and maintain the body’s chemical balance.
- Regulation of Fluid and Electrolyte Balance: The kidneys help regulate the body’s fluid levels, ensuring that the right amount of water is retained or excreted. They also regulate the balance of electrolytes such as sodium, potassium, and calcium, which are crucial for nerve and muscle function, among other things.
- Acid-Base Balance: The kidneys help maintain the body’s acid-base balance by regulating the levels of acids and bases in the blood. This is important for proper cellular function and overall pH balance.
- Blood Pressure Regulation: The kidneys play a role in regulating blood pressure by producing hormones that influence blood vessel constriction and fluid balance.
- Red Blood Cell Production: The kidneys produce a hormone called erythropoietin, which stimulates the production of red blood cells in the bone marrow. Red blood cells are essential for oxygen transport.
- Vitamin D Activation: The kidneys play a role in converting inactive vitamin D into its active form, which is important for calcium absorption and bone health.
- Waste Excretion: The kidneys eliminate waste products, such as urea and creatinine, from the body through urine.
Healthy kidney function is crucial for overall well-being. When the kidneys are unable to perform their functions adequately, it can lead to various health issues, including kidney disease, electrolyte imbalances, fluid retention, and more. Chronic kidney disease (CKD) is a condition where the kidneys gradually lose their function over time, potentially leading to kidney failure if not managed properly. Common causes of kidney disease include diabetes, high blood pressure, and certain genetic conditions.
Regular medical check-ups, a balanced diet, staying hydrated, managing underlying health conditions, and avoiding excessive consumption of alcohol and certain medications are some of the ways to support and maintain kidney function. If you have concerns about your kidney health, it’s important to consult a healthcare professional for proper evaluation and guidance.
Healthy kidneys filter about half a cup of blood every minute, removing waste products and excess water to make urine. Urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of your bladder. Your bladder stores urine. Your kidneys, ureters and bladder are part of your urinary tract.
The urinary tract refers to the kidneys, ureters, bladder, and urethra.
You have two kidneys that filter your blood, removing waste products and excess water to make urine.
Why are kidneys important?
Your kidneys remove waste and extra fluid from your body. Your kidneys also remove acids produced by your body’s cells and maintain a healthy balance of water, salt and minerals – such as sodium, calcium, phosphorus and potassium – in your blood.
Without this balance, the nerves, muscles and other tissues in your body cannot function normally.
Your kidneys also make hormones that help
- control your blood pressure
- Red blood cells NIH Create external link
- keep your bones strong and healthy
- Watch a video about what the kidneys do External link.
How do my kidneys work?
Each of your kidneys is made up of about one million filtering units called nephrons. Each nephron consists of a filter, called a glomerulus, and a tubule. Nephrons work through a two-step process: The glomerulus filters your blood, and the tubule returns essential substances to your blood and removes waste.
Illustration of a nephron showing that a blood vessel from the renal artery travels toward the glomerulus before branching into a U-shaped tubule and leading to the renal vein.
Each nephron contains a glomerulus to filter your blood and a tubule that returns essential substances to your blood and removes excess waste. The waste material and extra water become urine.
the glomerulus filters your blood
As blood flows into each nephron, it enters a cluster of tiny blood vessels – the glomerulus. The thin walls of the glomerulus allow small molecules, wastes and fluid – mostly water – to pass into the tubule. Large molecules, such as proteins and blood cells, reside in the blood vessel.
The ducts return essential substances to your blood and carry away waste products.
A blood vessel runs alongside the duct. As the filtered fluid moves along the duct, the blood vessel reabsorbs almost all of the water along with the minerals and nutrients your body needs. The duct helps to remove excess acid from the blood. The fluid and waste material left in the duct becomes urine.
How does blood flow through my kidneys?
Blood flows to your kidneys through the renal artery. This large blood vessel divides into smaller and smaller blood vessels until the blood reaches the nephron. In the nephron, your blood is filtered by the tiny blood vessels of the glomeruli and then flows out of your kidney through the renal vein.
Your blood passes through your kidneys several times a day. Your kidneys filter about 150 quarts of blood in a day. Most of the water and other substances that are filtered by your glomeruli are returned to your blood by the tubules. Only 1 to 2 quarts of urine is formed. Children produce less urine than adults, and the amount produced depends on their age.
It seems like you’re asking about how the kidneys work. The kidneys are remarkable organs that perform several vital functions to maintain the body’s internal environment. Here’s an overview of how kidney function works:
- Filtration: The primary function of the kidneys is to filter the blood and remove waste products, excess fluids, and electrolytes. This process takes place in microscopic structures within the kidneys called nephrons. Each kidney contains thousands of nephrons.
- Glomerular Filtration: The blood enters the kidneys through the renal artery. Within each nephron, there is a tiny blood vessel cluster called the glomerulus. Blood pressure forces water, dissolved substances, and small molecules (such as waste products) out of the blood and into the nephron, forming a fluid called filtrate.
- Tubular Reabsorption: The filtrate then flows through a series of tubules where essential substances, such as glucose, amino acids, and electrolytes, are reabsorbed back into the bloodstream. This ensures that important nutrients are not lost in the urine.
- Tubular Secretion: In this stage, additional waste products and excess substances are actively transported from the blood into the tubules. This further helps to eliminate waste and regulate the body’s chemical balance.
- Formation of Urine: The remaining fluid, now called urine, continues to flow through the tubules and into the collecting ducts. The urine is eventually transported to the renal pelvis and then to the bladder through the ureters. The bladder stores the urine until it is ready to be excreted from the body.
- Hormone Regulation: The kidneys also produce hormones that play important roles in the body. For example, they produce erythropoietin, which stimulates the production of red blood cells, and renin, which helps regulate blood pressure.
- Fluid and Electrolyte Balance: The kidneys help maintain the balance of fluids and electrolytes in the body. They regulate the levels of sodium, potassium, calcium, and other ions to ensure proper nerve and muscle function, fluid volume, and blood pressure.
- Acid-Base Balance: The kidneys play a crucial role in regulating the body’s acid-base balance. They help excrete hydrogen ions to maintain a stable pH level in the blood and tissues.
In summary, the kidneys work to filter the blood, remove waste products, regulate fluid and electrolyte balance, and help maintain the body’s overall internal environment. This intricate process is essential for maintaining good health. If the kidneys are not functioning properly, it can lead to a range of health issues and complications.