Kidneys: Anatomy, Function , Diseases & How They Work

The kidneys are vital organs that perform many functions to keep your blood clean and chemically balanced. They are also involved in regulating blood pressure, producing hormones, and maintaining fluid and electrolyte balance.

In this article, we will explore the location, anatomy, function, and health of the kidneys, as well as some common diseases and disorders that affect them.

Location and Anatomy of the Kidneys

The kidneys are two bean-shaped organs, each about the size of a fist. They are located on either side of the spine, just below the rib cage, in the back of the abdomen. They are partially protected by the lower ribs and the muscles of the back.

The kidneys are composed of three main layers:

  • The renal cortex
  • The renal medulla,
  • The renal pelvis.

The renal cortex is the outer layer that contains the nephrons, the functional units of the kidney. The renal medulla is the inner layer that contains the renal pyramids, the cone-shaped structures that collect urine from the nephrons. The renal pelvis is the funnel-shaped cavity that connects the kidney to the ureter, the tube that carries urine to the bladder.

Each kidney has about 1 million nephrons, which are microscopic structures that filter the blood and produce urine. Each nephron consists of two parts:

  • The glomerulus
  • The tubule.

The glomerulus is a cluster of capillaries that filters the blood plasma and allows water and small molecules to pass through. The tubule is a long, twisted tubethat reabsorbs and secretes substances to adjust the composition of the urine.

The urine then flows from the tubule to the collecting duct, which joins other ducts to form the renal pyramid.

Function and Health of the Kidneys

The kidneys perform several important functions that help maintain the health and balance of the body. Some of these functions are:

¡》Filtering the blood:

The kidneys filter about 200 liters of blood every day, removing waste products, toxins, excess water, and salts. The waste products and excess water are excreted as urine, while the salts and other substances are reabsorbed into the blood.

The kidneys also regulate the pH, or acidity, of the blood by excreting or retaining hydrogen ions and bicarbonate ions.

¡¡》Regulating blood pressure:

The kidneys help control blood pressure by adjusting the amount of fluid and sodium in the body. When the blood pressure is low, the kidneys secrete a hormone called renin, which activates a system that constricts the blood vessels and increases the blood volume and pressure.

When the blood pressure is high, the kidneys excrete more sodium and water, which lowers the blood volume and pressure.

¡¡¡》Producing hormones:

The kidneys produce several hormones that have various effects on the body. For example, the kidneys produce erythropoietin, which stimulates the production of red blood cells in the bone marrow.

The kidneys also produce calcitriol, which is the active form of vitamin D, which helps regulate the absorption of calcium and phosphorus in the intestines and the deposition of calcium in the bones.

The kidneys also produce prostaglandins, which are involved in inflammation, pain, and fever.

¡V》Maintaining fluid and electrolyte balance:

The kidneys help maintain the balance of fluids and electrolytes in the body by adjusting the amount and concentration of urine.

The kidneys respond to the signals from the brain, the heart, and the hormones to regulate the water and salt intake and output. The kidneys also balance the levels of potassium, calcium, magnesium, phosphate, and other electrolytes in the blood.

The health of the kidneys depends on several factors, such as diet, lifestyle, genetics, and medical conditions.

Some of the ways to keep the kidneys healthy are:

¡》Drinking enough water:

Water helps the kidneys flush out the waste products and toxins from the body. It also prevents dehydration, which can cause kidney stones and kidney damage.

The recommended amount of water intake varies depending on the age, weight, activity level, and climate, but generally, it is about 2 to 3 liters per day for adults.

¡¡¡》Eating a balanced diet:

A balanced diet that includes fruits, vegetables, whole grains, lean proteins, and healthy fats can provide the nutrients and antioxidants that the kidneys need to function properly.

It can also prevent obesity, diabetes, and high blood pressure, which are risk factors for kidney disease. Some of the foods that are good for the kidneys are berries, apples, grapes, cabbage, cauliflower, garlic, onion, and fish.

Some of the foods that should be limited or avoided are salt, sugar, processed foods, red meat, alcohol, and caffeine.

¡V》Exercising regularly:

Exercise can help the kidneys by improving the blood circulation, lowering the blood pressure, reducing the inflammation, and preventing the accumulation of fat in the kidneys.

Exercise can also reduce the stress, which can affect the kidney function. The recommended amount of exercise varies depending on the age, fitness level, and goals, but generally, it is about 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous-intensity aerobic activity per week for adults.

V》Avoiding smoking and drugs:

Smoking and drugs can harm the kidneys by increasing the blood pressure, reducing the blood flow, causing inflammation, and damaging the tissues and cells of the kidneys.

Smoking and drugs can also interact with some medications and affect their metabolism and excretion by the kidneys. Therefore, it is advisable to quit smoking and avoid using illegal or recreational drugs, as well as to consult with a doctor before taking any prescription or over-the-counter drugs.

》Getting regular check-ups:

Regular check-ups can help detect and treat any kidney problems early, before they become serious and irreversible. Some of the tests that can assess the kidney function are blood tests, urine tests, imaging tests, and kidney biopsy.

Some of the signs and symptoms that may indicate a kidney problem are changes in the colour, odour, or amount of urine, swelling in the legs, ankles, or feet, fatigue, nausea, vomiting, loss of appetite, itching, muscle cramps, and back pain.

Diseases and Disorders of the Kidneys

The kidneys can be affected by various diseases and disorders that can impair their function and cause complications. Some of the common diseases and disorders of the kidneys are:

1. Kidney stones:

Kidney stones are hard deposits of minerals and salts that form in the kidneys or the urinary tract. They can cause severe pain, blood in the urine, infection, and obstruction of the urine flow.

Kidney stones can be caused by dehydration, high intake of calcium, oxalate, or uric acid, genetic factors, or certain medications. Kidney stones can be treated by drinking plenty of water, taking painkillers, using sound waves to break up the stones, or surgery to remove the stones.

2. Kidney infection:

Kidney infection, or pyelonephritis, is a bacterial infection that affects one or both kidneys. It can cause fever, chills, back pain, abdominal pain, nausea, vomiting, and cloudy or foul-smelling urine.

Kidney infection can be caused by a urinary tract infection that spreads to the kidneys, or by a direct invasion of bacteria from the blood or other organs.

Kidney infection can be treated by antibiotics, fluids, and painkillers. If left untreated, kidney infection can lead to kidney damage, sepsis, or kidney failure.

3. Kidney failure:

Kidney failure, or renal failure, is a condition where the kidneys lose their ability to filter the blood and remove the waste products and excess fluids from the body.

It can cause a build-up of toxins, electrolyte imbalance, fluid overload, anaemia, bone disease, and cardiovascular disease. Kidney failure can be acute or chronic, depending on the duration and severity of the kidney damage.

Kidney failure can be caused by diabetes, high blood pressure, glomerulonephritis, polycystic kidney disease, lupus, or other factors.

Kidney failure can be treated by dialysis, which is a process that artificially filters the blood using a machine or a membrane, or by kidney transplantation, which is a surgery that replaces the diseased kidney with a healthy one from a donor.

4. Kidney cancer:

Kidney cancer is a type of cancer that originates in the cells of the kidney. It can cause blood in the urine, back pain, weight loss, fatigue, fever, and night sweats.

Kidney cancer can be caused by smoking, obesity, hypertension, genetic mutations, or exposure to certain chemicals or radiation.

Kidney cancer can be diagnosed by blood tests, urine tests, imaging tests, and biopsy. Kidney cancer can be treated by surgery, chemotherapy, radiation therapy, immunotherapy, or targeted therapy.


The kidneys are essential organs that perform many functions to keep the body healthy and balanced. They filter the blood, regulate the blood pressure, produce hormones, and maintain the fluid and electrolyte balance.

The kidneys can be affected by various diseases and disorders that can impair their function and cause complications. Therefore, it is important to take care of the kidneys by drinking enough water, eating a balanced diet, exercising regularly, avoiding smoking and drugs, and getting regular check-ups.

By doing so, you can ensure the health and well-being of your kidneys and your whole body.


  • Pancreas: Functions, possible problems and everything you need to know
  • All About the Central Nervous System: What You Need to Know
  • All about the peripheral nervous system: What it is and how it works
  • Difference between the CNS and peripheral nervous system

Leave a Comment

Your email address will not be published. Required fields are marked *

3 thoughts on “Kidneys: Anatomy, Function , Diseases & How They Work”

  1. I really love your blog.. Very nice colors & theme. Did you make this amazing site yourself? Please reply back as I’m wanting to create my own personal blog and want to find out where you got this from or exactly what the theme is called. Thank you!

Scroll to Top