The kidneys are vital organs in the human body responsible for several essential functions, which play a crucial role in maintaining overall health. Here’s an overview of their functions and importance:
- Filtration of Blood: The primary function of the kidneys is to filter blood to remove waste products and excess substances, such as toxins, electrolytes, and metabolic waste products like urea and creatinine. This process occurs in structures called nephrons.
- Regulation of Blood Pressure: The kidneys help regulate blood pressure by controlling the volume of blood in the body and releasing the enzyme renin, which affects blood vessel constriction and fluid balance.
- Fluid and Electrolyte Balance: They maintain the proper balance of fluids and electrolytes (sodium, potassium, calcium, etc.) in the body. This balance is essential for various bodily functions, including nerve and muscle function.
- Acid-Base Balance: The kidneys help regulate the pH of the blood by excreting hydrogen ions and reabsorbing bicarbonate ions. This is crucial for maintaining a stable acid-base balance.
- Red Blood Cell Production: The kidneys produce and release erythropoietin, a hormone that stimulates the production of red blood cells in the bone marrow. This helps maintain adequate oxygen-carrying capacity in the blood.
- Metabolism of Vitamin D: The kidneys are involved in the activation of vitamin D, which is necessary for calcium absorption in the intestines. Proper calcium levels are essential for bone health and many cellular processes.
- Detoxification: The kidneys play a vital role in detoxifying the body by filtering out waste and harmful substances. They also help eliminate drugs and their metabolites from the body.
- Hormone Regulation: Apart from erythropoietin and renin, the kidneys are involved in the metabolism and regulation of various hormones and signaling molecules, including aldosterone, parathyroid hormone, and others.
- Excretion of Waste Products: The kidneys excrete various waste products, including urea, creatinine, and uric acid, which are byproducts of metabolism.
The functional unit of the kidney is the nephron, which consists of a renal corpuscle (containing the glomerulus, where filtration occurs) and a renal tubule (where reabsorption and secretion of substances occur). The filtered blood is eventually transformed into urine, which is then transported to the bladder for excretion.
It’s essential to maintain the health of your kidneys through a balanced diet, proper hydration, and regular exercise. Kidney diseases or dysfunction can lead to serious health issues, so taking care of these organs is crucial for overall well-being.
List some of the lesser known functions of the kidneys
In addition to their well-known functions, the kidneys have some lesser-known or more specialised roles in the body. Here are a few of these lesser-known functions:
- Blood Filtration Rate Control: The kidneys can adjust their filtration rate to manage the volume of blood being filtered, which is crucial in regulating blood pressure and maintaining overall fluid balance.
- Production of Prostaglandins: Kidneys produce prostaglandins, which are lipid compounds that have various effects on the body, including regulating blood flow, inflammation, and immune response.
- Metabolism of Insulin: The kidneys contribute to the metabolism of insulin, a hormone that regulates blood sugar levels. Dysfunction in this process can affect glucose regulation in the body.
- Glucose Homeostasis: While the liver is the primary organ involved in regulating blood glucose levels, the kidneys also play a minor role in reabsorbing glucose and maintaining stable blood sugar levels.
- Production of Erythropoietin: While the production of erythropoietin (a hormone that stimulates red blood cell production) is a well-known function, it’s worth noting that the kidneys can increase erythropoietin production in response to low oxygen levels in the blood, as occurs at high altitudes.
- Metabolism of Vitamin C: The kidneys play a role in the metabolism and excretion of vitamin C (ascorbic acid) from the body. They filter and reabsorb this vitamin as needed.
- Amino Acid Reabsorption: Some amino acids are reabsorbed in the renal tubules by the kidneys. This process helps maintain amino acid balance in the body.
- Immune Response Modulation: The kidneys can influence the immune system by releasing certain signaling molecules, affecting the body’s response to infections and inflammation.
- Metabolism of Steroids: The kidneys are involved in the metabolism and elimination of certain steroid hormones, including cortisol and aldosterone.
It’s important to note that while the kidneys have these lesser-known functions, they primarily focus on filtration, fluid balance, waste elimination, and the regulation of essential substances in the blood. Kidney health is crucial for maintaining these functions and overall well-being. If the kidneys are compromised or become diseased, it can lead to a wide range of health issues.
The make up of the kidneys
The kidneys are complex organs with a specific structure designed to carry out their vital functions. Here’s an overview of the makeup of the kidneys:
The kidneys are highly vascular organs, receiving about 20% of the cardiac output to ensure proper filtration and regulation of blood composition. Their intricate structure and functions are essential for maintaining the body’s overall health and homeostasis.
How does the kidneys work with other organs or systems in the body?
The kidneys work in coordination with other organs and systems in the body to maintain overall health and homeostasis. Here’s how the kidneys interact with various organs and systems:
- Cardiovascular System:
- The kidneys regulate blood pressure by controlling blood volume and releasing renin, which affects blood vessel constriction.
- They filter waste products from the bloodstream, helping to maintain the composition of the blood.
- Proper kidney function ensures adequate blood flow, which, in turn, supplies oxygen and nutrients to various tissues and organs.
- Endocrine System:
- The kidneys produce and release erythropoietin, a hormone that stimulates red blood cell production in the bone marrow.
- They contribute to the metabolism of various hormones, including aldosterone, which regulates sodium and potassium balance, and calcitriol (activated vitamin D), which affects calcium absorption in the intestines.
- Digestive System:
- The kidneys help maintain the body’s electrolyte balance, which can be influenced by the absorption of electrolytes in the digestive system.
- They play a role in the excretion of waste products, some of which originate from digestion and metabolism.
- Respiratory System:
- The kidneys indirectly influence the respiratory system by regulating the acid-base balance of the blood. If the blood becomes too acidic or alkaline, it can affect respiratory rate and depth.
- Nervous System:
- The kidneys are involved in regulating blood pressure, which can influence cerebral blood flow and, consequently, brain function.
- Electrolyte imbalances in the body can affect nerve impulses, muscle contractions, and overall neural function.
- Skeletal System:
- The kidneys, through the regulation of calcium and phosphate metabolism, contribute to the health and maintenance of bones. For example, they are involved in the activation of vitamin D, which is essential for calcium absorption.
- Immune System:
- The kidneys play a role in immune response modulation through the release of certain signaling molecules.
- They help filter and eliminate waste products and toxins from the body, which can have an impact on overall immune function.
- Urinary System:
- The kidneys work in tandem with the urinary system, including the ureters, bladder, and urethra, to transport and excrete urine from the body.
- Lymphatic System:
- The kidneys are not directly part of the lymphatic system, but the lymphatic vessels may drain excess tissue fluid back into the bloodstream, which the kidneys subsequently filter.
The kidneys are intricately connected to many systems within the body, and their functions have widespread effects on overall health and homeostasis. When there is dysfunction in the kidneys, it can lead to various health problems and imbalances throughout the body. Therefore, maintaining kidney health is essential for overall well-being.
What happens to your body if the kidneys stop working properly or fails?
Kidney failure or the inability of the kidneys to work properly can have severe and widespread effects on the body. There are two main types of kidney failure: acute and chronic. Here’s how each type can impact the body:
- Acute Kidney Failure:
- Acute kidney failure typically occurs suddenly and is often reversible if identified and treated promptly. It can result from conditions such as severe dehydration, infection, medication toxicity, or trauma.
- Symptoms can include decreased urine output, fluid retention, electrolyte imbalances, fatigue, and confusion.
- Treatment may involve addressing the underlying cause, providing supportive care, and potentially dialysis in severe cases.
- Chronic Kidney Disease (CKD):
- Chronic kidney disease is a long-term, progressive condition where the kidneys gradually lose their ability to function. It can result from conditions like diabetes, hypertension, or certain genetic disorders.
- Over time, CKD can lead to a buildup of waste products and fluid in the body, causing symptoms such as fatigue, oedema (swelling), high blood pressure, and anaemia.
- Advanced CKD may require long-term management, including dietary changes, medication, and, in some cases, kidney transplant or dialysis.
The consequences of kidney failure on the body are significant and include:
- Fluid and Electrolyte Imbalance:
- The kidneys are responsible for maintaining the balance of fluids and electrolytes in the body. Kidney failure can lead to fluid retention, oedema, and electrolyte imbalances, which can affect various organ systems.
- When the kidneys fail to adequately filter waste products from the blood, a condition called uremia occurs. Symptoms include nausea, vomiting, loss of appetite, fatigue, and mental confusion.
- Hypertension (High Blood Pressure):
- The kidneys play a crucial role in blood pressure regulation. Kidney failure can lead to uncontrolled high blood pressure, increasing the risk of heart disease, stroke, and other complications.
- The kidneys produce erythropoietin, a hormone that stimulates red blood cell production. In kidney failure, erythropoietin production decreases, leading to anaemia and a reduced oxygen-carrying capacity in the blood.
- Bone and Mineral Disorders:
- Kidney failure can disrupt calcium and phosphorus balance, leading to bone problems, such as weakened bones and an increased risk of fractures.
- Cardiovascular Complications:
- Kidney disease is associated with an increased risk of heart disease and heart-related complications, including heart failure.
- Neurological and Cognitive Effects:
- Uremia can affect the brain, leading to symptoms like confusion, difficulty concentrating, and memory problems.
- Kidney failure can weaken the immune system, making the individual more susceptible to infections.
- Gastrointestinal Problems:
- Nausea, vomiting, and gastrointestinal symptoms are common in individuals with kidney failure.
- Increased Risk of Infections and Sepsis:
- The weakened immune system and the buildup of waste products in the body can increase the risk of infections, which can sometimes progress to sepsis, a life-threatening condition.
It’s important to manage kidney health through regular check-ups, a healthy lifestyle, and the management of underlying conditions. If kidney failure occurs, medical intervention and potential kidney replacement therapies, like transplant or dialysis, may be necessary to maintain the body’s functions and overall well-being.
List of diseases of the kidneys
There are various kidney diseases and conditions that can affect the structure and function of the kidneys. Some common kidney diseases and disorders include:
- Chronic Kidney Disease (CKD): A long-term condition where the kidneys gradually lose their ability to function. It can result from conditions like diabetes, high blood pressure, or certain genetic disorders.
- Acute Kidney Injury (AKI): Sudden loss of kidney function, often due to factors like severe dehydration, infection, medication toxicity, or trauma.
- Polycystic Kidney Disease (PKD): A genetic disorder where cysts form in the kidneys, leading to their enlargement and potentially reduced function.
- Glomerulonephritis: Inflammation of the glomeruli, the filtering units in the kidneys. It can be acute or chronic and may be caused by infections, autoimmune conditions, or other factors.
- Nephrotic Syndrome: A group of symptoms (proteinuria, oedema, hypoalbuminemia, and hyperlipidemia) indicating kidney damage. It can result from various underlying causes.
- Kidney Stones: Hard deposits of minerals and salts that can form in the kidneys and cause severe pain when they move into the urinary tract.
- Hydronephrosis: The swelling of one or both kidneys due to the backup of urine caused by an obstruction or other factors.
- Interstitial Nephritis: Inflammation of the kidney’s tubules and surrounding structures. It can be caused by medications, infections, or autoimmune conditions.
- Renal Cell Carcinoma: The most common type of kidney cancer, which originates in the cells of the renal tubules.
- Wilms Tumor (Nephroblastoma): A rare kidney cancer that primarily affects children.
- Alport Syndrome: A genetic disorder that affects the glomeruli, leading to kidney disease, hearing loss, and eye abnormalities.
- Renal Artery Stenosis: The narrowing of the renal arteries, which can lead to reduced blood flow to the kidneys and high blood pressure.
- Renal Osteodystrophy: A group of bone disorders that result from chronic kidney disease, leading to imbalances in calcium and phosphorus metabolism.
- IgA Nephropathy (Berger’s Disease): An immune system disorder that affects the glomeruli and can lead to kidney damage.
- Haemolytic Uremic Syndrome (HUS): A condition that can lead to kidney failure, often caused by an infection with E. coli bacteria.
- Fabry Disease: A genetic disorder that can lead to the buildup of a certain type of fat in the body’s cells, including those in the kidneys.
- Amyloidosis: A condition in which abnormal proteins (amyloids) build up in various tissues, including the kidneys.
- Minimal Change Disease: A type of nephrotic syndrome that primarily affects children and often responds well to treatment.
These are just a few examples of kidney diseases and conditions. Many factors, including genetics, lifestyle, and underlying medical conditions, can contribute to kidney problems. Early detection, appropriate medical care, and lifestyle management are key to preventing or managing these conditions. If you suspect you have a kidney-related issue, it’s essential to consult a healthcare professional for a proper diagnosis and treatment.
Foods and substances we consume that are toxic to the kidneys
The kidneys play a crucial role in filtering waste products and toxins from the blood, so it’s important to be aware of substances and foods that can be toxic to the kidneys when consumed in excessive amounts or over an extended period of time. Here are some common foods and substances that can potentially harm the kidneys:
It’s essential to consume these substances in moderation and, when necessary, under the guidance of a healthcare professional. People with existing kidney conditions or those at risk of kidney problems should be especially cautious about their dietary and lifestyle choices. Staying hydrated, eating a balanced diet, and maintaining a healthy lifestyle can help protect kidney health.
What lifestyle choices supports the kidneys
Maintaining a healthy lifestyle is crucial for supporting kidney health and preventing kidney disease. Here are some lifestyle choices and habits that can help protect and support your kidneys:
- Limit Sodium: Reduce your intake of high-sodium and processed foods to help maintain healthy blood pressure and prevent kidney strain.
- Control Protein: Excessive protein intake can put added stress on the kidneys. If you consume flesh ‘protein’ in moderation.
- Manage Phosphorus: Limit high-phosphorus foods like carbonated drinks and processed foods, particularly if you have kidney disease.
- Watch Potassium: If you have kidney issues, managing potassium intake may be necessary, as high potassium levels can be harmful to the kidneys.
By making these lifestyle choices, you can reduce your risk of kidney disease and promote overall health.
Kidney disease symptoms
Kidney disease, especially in its early stages, often does not cause noticeable symptoms. Symptoms tend to become more apparent as kidney function declines. Common symptoms and signs of kidney disease may include:
- Changes in Urination:
- Frequent Urination: You may need to urinate more frequently, especially at night.
- Urgent Need to Urinate: A strong, sudden urge to urinate, often followed by little output.
- Difficulty Urinating: You may have trouble initiating or maintaining a urine stream.
- Blood in Urine (Haematuria): Urine may appear pink, red, or brown due to the presence of blood.
- Foamy Urine: Excessive protein in the urine can create a foamy appearance.
- Swelling (Oedema): Oedema, especially in the legs, ankles, and around the eyes, can occur due to fluid retention.
- Fatigue: Kidney disease can lead to anaemia, causing fatigue and weakness.
- Shortness of Breath: Excess fluid in the body can accumulate in the lungs, leading to shortness of breath.
- Itching and Skin Rash: The buildup of waste products in the body can cause skin irritation.
- Loss of Appetite: Nausea and a metallic taste in the mouth can lead to a reduced appetite.
- Nausea and Vomiting: Uremia, a buildup of waste products in the blood, can cause nausea and vomiting.
- Unexplained Weight Loss: Kidney disease can lead to muscle wasting and weight loss.
- High Blood Pressure: Kidney disease can contribute to or exacerbate hypertension (high blood pressure).
- Muscle Cramps and Twitches: Electrolyte imbalances can result in muscle cramps and twitches.
- Back Pain: Pain in the back, just below the ribcage, is common with kidney infections and some kidney conditions.
- Painful Urination: Pain or a burning sensation when urinating may indicate a urinary tract infection.
- Changes in Urine Output: A significant decrease or increase in urine output can be a concern.
- Metallic Taste in the Mouth: A persistent metallic or ammonia-like taste in the mouth can be a symptom of kidney dysfunction.
- Difficulty Concentrating and Mental Confusion: Uremia can affect brain function, leading to difficulty concentrating and confusion.
It’s important to note that kidney disease can be caused by various underlying conditions, such as diabetes, high blood pressure, and kidney infections. Additionally, many symptoms of kidney disease are nonspecific and can be related to other health issues.
A detailed list of foods that help the kidneys
A kidney-friendly diet can help support kidney health and manage certain kidney conditions. Here is a detailed list of foods that can be beneficial for the kidneys:
- Berries: Blueberries, strawberries, and raspberries are rich in antioxidants that may help protect kidney cells from damage.
- Red Bell Peppers: These are low in potassium and a good source of vitamins A and C.
- Cabbage: A cruciferous vegetable that is low in potassium and a source of vitamin K and fiber.
- Onions: A flavourful addition to dishes, onions are low in potassium and high in antioxidants.
- Apples: High in fiber and antioxidants, apples can be a healthy snack for kidney health.
- Cherries: Rich in antioxidants, cherries may help reduce inflammation.
- Olive Oil: A healthy source of monounsaturated fats.
- Asparagus: A vegetable that is high in fibre and low in potassium.
- Pears: A fruit that is low in potassium and high in fibre.
- Basil: A flavourful herb that can be used to season food without adding extra sodium.
- Red Grapes: Contain antioxidants and may have anti-inflammatory properties.
- Watermelon: A hydrating and low-potassium fruit.
- Cucumber: A hydrating and low-potassium vegetable.
- Cilantro: A flavourful herb that can add variety to kidney-friendly recipes.
It’s important to remember that the dietary needs of individuals with kidney issues may vary based on their specific condition, so it’s advisable to consult with a healthcare provider or a registered dietitian for personalised dietary recommendations. For those with advanced kidney disease, it may be necessary to further restrict certain nutrients like potassium, phosphorus, and protein.
List of herbs for the kidneys
Herbs have been used for centuries in traditional medicine to support kidney health and function. While the efficacy of these herbs is often based on traditional knowledge and anecdotal evidence, some scientific research suggests they may have benefits for the kidneys. Here’s a list of herbs that are commonly used for kidney health, along with their potential effects:
- Dandelion (Taraxacum officinale):
- Diuretic: Dandelion leaves are known for their diuretic properties, which can help increase urine production and promote the excretion of waste products, potentially supporting kidney health.
- Nettle (Urtica dioica):
- Diuretic: Nettle is believed to have mild diuretic properties, which can assist in removing excess fluids and waste from the body.
- Cranberry (Vaccinium macrocarpon):
- Urinary Tract Health: Cranberry has been traditionally used to support urinary tract health and may help prevent urinary tract infections (UTIs).
- Horsetail (Equisetum arvense):
- Diuretic: Horsetail has diuretic properties and may promote increased urine production.
- Astragalus (Astragalus membranaceus):
- Immune Support: Astragalus is used in traditional Chinese medicine to strengthen the immune system and may indirectly support kidney health.
- Marshmallow Root (Althaea officinalis):
- Anti-Inflammatory: Marshmallow root has anti-inflammatory properties and may help reduce kidney inflammation.
- Ginger (Zingiber officinale):
- Anti-Inflammatory: Ginger has anti-inflammatory properties that may benefit the kidneys by reducing inflammation.
- Parsley (Petroselinum crispum):
- Diuretic: Parsley is often used as a diuretic to promote increased urine output.
- Corn Silk (Zea mays):
- Diuretic: Corn silk is traditionally used as a mild diuretic and is believed to help with kidney stones.
- Juniper (Juniperus communis):
- Diuretic: Juniper is known for its diuretic properties, which can increase urine output and potentially help with kidney function.
- Goldenrod (Solidago spp.):
- Diuretic: Goldenrod is traditionally used as a diuretic to increase urine production.
- Buchu (Agathosma betulina):
- Diuretic: Buchu is a diuretic herb that has been used for urinary tract health.
It’s important to note that while these herbs may offer potential benefits for kidney health, they should be used with caution and under the guidance of a healthcare professional or a trained herbalist. Some herbs may interact with medications or have contraindications in certain medical conditions. Additionally, the effectiveness of herbal remedies can vary from person to person.
Research papers done on the kidneys
Research papers on the kidneys cover a wide range of topics, from kidney function and diseases to treatment options and advancements in kidney-related science. Here is a list of research papers, but please note that this list is not exhaustive. New research papers are constantly being published, so I recommend using academic databases like PubMed to find the latest research on kidney-related topics. Here are a few:
- Title: “Chronic Kidney Disease: Global Dimension and Perspectives”
Authors: Vivekanand Jha, Guillermo Garcia-Garcia, Kunitoshi Iseki, Zuo Li, Saraladevi Naicker, Brett Plattner, Rajiv Saran, Angela Yee-Moon Wang, Chih-Wei Yang
- Title: “The Role of the Kidney in Drug Elimination: Transport, Metabolism and the Impact of Kidney Disease on Drug Clearance”
Authors: J O Miners, X Yang, K M Knights, L Zhang
Publication: Clinical Pharmacology & Therapeutics (June 2017)
- Title: “Global, regional, and national burden of chronic kidney disease, 1990–2017: a systematic analysis for the Global Burden of Disease Study 2017”
Authors: GBD Chronic Kidney Disease Collaboration
Publication: The Lancet (2020). https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30045-3/fulltext
- Title: “Cardiovascular Disease in Chronic Kidney Disease”
Authors: Joachim Jankowski, Jürgen Floege, Danilo Fliser, Michael Böhm and Nikolaus Marx
Publication: AHA Journals (2021): https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.120.050686
- Title: “KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease”
Publication: 2012: https://kdigo.org/wp-content/uploads/2017/02/KDIGO_2012_CKD_GL.pdf
- Title: “Chronic Kidney Disease: The Gut-Kidney Connection?”
Authors: Jeffrey Bland, PhD, FACN, FACB, Associate Editor
Publication: Integrative Medicine Vol. 16, No. 2 (2017)
- Title: “Role of the gut microbiome in chronic diseases: a narrative review”
Author: Amrita Vijay 1 ✉ and Ana M. Valdes 1,2
Publication: European Journal of Clinical Nutrition (2022) 76:489–501; https://doi.org/10.1038/s41430-021-00991-6
- Title: “Wound Healing Complications in Kidney Transplant Recipients Receiving Everolimus”
Author: Priscilla Ueno, Claudia Felipe, Alexandra Ferreira, Marina Cristelli, Laila Viana, Juliana Mansur, Geovana Basso, Pedro Hannun, Wilson Aguiar, Helio Tedesco Silva Jr, Jose Medina-Pestana
Publication: Transplantation 101(4):p 844-850, (2017).
- Title: “Kidney Stones: Pathophysiology, Diagnosis and Management”
Authors: Priscilla Cunningham, Helen Noble, Abdul-Kadhum Al-Modhefer, Ian Walsh
Publication: Published Online:11 Nov 2016https://doi.org/10.12968/bjon.2016.25.20.1112).
-Joseph Loscalzo, Anthony Fauci, Dennis Kasper, Stephen Hauser, Dan Longo, J. Larry Jameson. “Harrison’s Principles of Internal Medicine”
“National Kidney Foundation (NKF)”: The NKF’s website provides a wealth of information on kidney health, kidney diseases, and related topics.
PubMed: A free database of biomedical and life sciences literature. You can search for research papers, clinical studies, and articles on kidney-related topics.
The Lancet: A reputable medical journal with articles on various aspects of kidney health and research.
Clinical Journal of the American Society of Nephrology (CJASN): A leading journal in the field of nephrology, with research articles and reviews on kidney-related topics.
The New England Journal of Medicine (NEJM): A prominent medical journal that covers research and clinical findings related to kidney diseases and treatment.
World Kidney Day (WKD): The official website for World Kidney Day offers resources, educational materials, and information on kidney health.
American Journal of Kidney Diseases (AJKD): Another authoritative source for research and clinical articles related to kidney diseases and nephrology.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK): The NIDDK, part of the National Institutes of Health (NIH), provides resources, research information, and publications related to kidney health.
Mayo Clinic: The Mayo Clinic’s website offers a wealth of information on various health topics, including kidney diseases and conditions.
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