4.6 Disorders of Human Urinary System

Introduction

The urinary system can be affected by various disorders that impair its function. These disorders can lead to kidney damage and, if untreated, kidney failure. This topic introduces the common disorders of the human urinary system, including their causes and effects.

Definition

Disorders of the human urinary system are conditions that affect the normal functioning of the kidneys, ureters, bladder, or urethra. They can lead to renal diseases and renal failure.

Main Idea

There are many types of illnesses that lead to renal diseases and renal failure. Urinary tract infections are common, particularly in females. The most common causes of kidney damage are:

• Diabetes
• High blood pressure
• Infections
• Kidney stones
• Glomerular blockage

Core Concept

Common Disorders of the Urinary System

Detailed Explanation

1. Urinary Tract Infections (UTIs)

What they are: Infections of the urinary tract, including the bladder, urethra, and kidneys.

Who is affected: Common particularly in females.

Causes:

• Bacteria (most commonly Escherichia coli).
• Poor hygiene.
• Holding urine for long periods.
• Dehydration.

Symptoms:

• Burning sensation during urination.
• Frequent urge to urinate.
• Cloudy or bloody urine.
• Pelvic pain.

Simple explanation: UTIs are infections caused by bacteria entering the urinary tract. They are more common in women because the urethra is shorter.

2. Kidney Stones

What they are: Stones may develop in any part of the urinary system. Kidney stones are usually composed of uric acid crystals or calcium oxalate.

Causes:

• Presence of high level of calcium in the blood because of other diseases.
• Presence of higher level of oxalate in the blood results in the formation of calcium oxalate stones.
• A decrease in water intake.
• Age and family history.

Symptoms:

• Severe pain in the kidney, abdomen, pelvis, and legs.
• Nausea and vomiting.

Treatment:

• About 90% of all kidney stones can pass through the urinary system by drinking plenty of water.
• The kidney stone may be removed by surgery.
• There is a non-surgical method of stone removal called lithotripsy.
• Lithotripsy is a technique to break up stones that form in the kidney and ureter by shock waves targeted from outside the body.

Simple explanation: Kidney stones are hard crystals that form in the kidney. They can cause severe pain. Drinking water helps them pass. If not, surgery or lithotripsy may be needed.

3. Kidney Failure

What it is: If one kidney fails to function, the person can still lead a normal life with another kidney. If both the kidneys fail to work, it is fatal.

Definition: A general term for declined kidney function is called kidney failure.

What happens:

• The rise in urea causes an increase in blood pressure and anaemia, etc.
• If kidney failure is not treated, death will result within a couple of weeks.

Types:

Causes of kidney failure:

• Diabetes: The most common cause of kidney failure.
• High blood pressure: The second most common cause of kidney failure.
• Autoimmune diseases: Such as lupus.
• Genetic diseases: Such as polycystic kidney disease.
• Urinary tract problems: Such as kidney stones.
• Medications: Some drugs, such as lithium.
• Dehydration: Losing too much body fluid.
• Kidney trauma: An injury to the kidney from an outside force.
• Processed foods: A 2022 study found that eating a lot of processed foods can increase the risk of kidney disease.

Simple explanation: Kidney failure is when the kidneys stop working properly. It can be acute (sudden) or chronic (over time). Diabetes and high blood pressure are the most common causes.

4. Glomerular Blockage

What it is: Blockage of the glomerulus, the filtering unit of the kidney.

Causes:

• Inflammation of the glomerulus (glomerulonephritis).
• Deposition of immune complexes.
• Infections.

Effect:

• Reduced filtration rate.
• Waste products accumulate in the blood.

Simple explanation: Glomerular blockage is when the filtering units of the kidney become blocked, reducing their ability to filter blood.

Intermediate Level

Common disorders of the urinary system:

Key points:

• UTIs are common in females.
• Kidney stones are usually composed of uric acid or calcium oxalate.
• Lithotripsy is a non-surgical method to break stones.
• Kidney failure can be acute or chronic.
• Diabetes and high blood pressure are the leading causes of kidney failure.

Important Points

• - There are many types of illnesses that lead to renal diseases and renal failure.
• - Urinary tract infections are common particularly in females.
• - The most common causes of kidney damage are diabetes, high blood pressure, infections, kidney stones, and glomerular blockage.
• - Stones may develop in any part of the urinary system.
• - Kidney stones are usually composed of uric acid crystals or calcium oxalate.
• - The causes of kidney stones are: high level of calcium in the blood, higher level of oxalate in the blood, decrease in water intake, age and family history.
• - About 90% of all kidney stones can pass through the urinary system by drinking plenty of water.
• - The kidney stone may be removed by surgery.
• - Lithotripsy is a technique to break up stones by shock waves targeted from outside the body.
• - If one kidney fails to function, the person can still lead a normal life with another kidney.
• - If both the kidneys fail to work, it is fatal.
• - A general term for declined kidney function is called kidney failure.
• - Kidney failure can be acute (sudden) or chronic (over time).
• - The most common cause of kidney failure is diabetes.
• - The second most common cause of kidney failure is high blood pressure.

Remember

• - UTIs = urinary tract infections, common in females
• - Kidney stones = uric acid or calcium oxalate crystals
• - Causes of kidney stones = high calcium, high oxalate, low water intake
• - Lithotripsy = breaks stones by shock waves
• - Kidney failure = decline in kidney function
• - Types of kidney failure = acute (AKI) and chronic (CKD)
• - Causes of kidney failure = diabetes, high blood pressure, infections, stones
• - Diabetes = most common cause of kidney failure
• - High blood pressure = second most common cause

Common Mistakes

• 1. Confusing kidney stones and kidney failure.
• - Kidney stones = solid crystals in the kidney.
• - Kidney failure = decline in kidney function.
• 2. Thinking UTIs only affect females.
• - UTIs are more common in females but can affect males too.
• 3. Believing all kidney stones require surgery.
• - About 90% of kidney stones pass by drinking plenty of water.
• 4. Forgetting the role of lithotripsy.
• - Lithotripsy is a non-surgical method to break kidney stones using shock waves.
• 5. Thinking kidney failure is always fatal.
• - If one kidney fails, the other can compensate. If both fail, it is fatal without treatment.
• 6. Mixing up acute and chronic kidney failure.
• - Acute = sudden, often reversible.
• - Chronic = over time, permanent.
• 7. Believing kidney failure has no treatment.
• - Dialysis and kidney transplant are treatment options.

Quick Revision

60-Second Revision

• UTIs = urinary tract infections; common in females; bacteria; antibiotics
• Kidney stones = uric acid or calcium oxalate; high calcium, high oxalate, low water intake; lithotripsy
• Kidney failure = decline in kidney function; acute (AKI) or chronic (CKD)
• Causes of kidney failure = diabetes (most common), high blood pressure (second most common), infections, stones
• Treatment = dialysis, kidney transplant
• Warning: Do not confuse kidney stones (crystals) with kidney failure (decline in function).