Excretory System Diseases Study guide


What do your lungs, liver, sweat glands, and kidneys all have in common? Each and every one is part of your excretory system! And we’re sure there’s nothing you’d rather be doing right now than learning about excretion, right? If you’re not too hot on that subject, you’re actually in luck. Because though we’ll be briefly overviewing the system itself, we’re going to be focusing primarily on some of the diseases that affect it. Even more fun, right? Let’s get started.

The Excretory System

The Excretory System includes the skin, liver, large intestine, lungs, and urinary tract. It’s main purpose is to remove waste from your body, including excess water, nitrogen, salts, toxins, medications, and drugs. Today we’ll be focusing on the urinary part of the system, which is composed of four parts: the kidneys, ureters, bladder, and urethra.

The Urinary System acts as a filter, eliminating waste from your body through urine. To do so, blood enters your Kidneys through a bunch of tiny blood vessels where it is filtered to separate waste from vitamins, minerals, nutrients and proteins. The good stuff is returned to your bloodstream and the waste products are transferred to your urine, which then travels from the kidneys to the Bladder through your Ureters (of which you have two–one for each kidney). The bladder stores your urine until you use the bathroom, where it finally leaves your body through your Urethra.

The most important part of the urinary system is the kidneys, which is why they’re the ones most typically affected by excretory diseases. Let’s go over five common examples of these diseases below: kidney stones, chronic kidney disease, urinary tract infections, kidney infections, and glomerulonephritis.

Kidney Stones

Kidney Stones are little crystals made of minerals and salts that form inside your kidneys and must eventually be passed down the ureter, into the bladder, through the ureters, and finally out of the urethra all on their own (in other words, you pee them out).

Kidney stones usually have no symptoms until they move into the ureter where they block the flow of urine, causing the kidneys to swell and the ureter to spasm (you can see this blockage in the 3D model represented by the yellow blobs).

When kidney stones reach the ureter, ‘no symptoms’ is quickly replaced by some immensely painful ones. These can include pain in your side, back, lower abdomen, or groin that comes and waves and changes in intensity. They can also make it hurt or burn when urinating, and make you feel like you need to urinate more often.

Though painful, kidney stones are usually not that dangerous. But if complications occur like a urinary tract infection, surgery may be required to remove them. Overall, would not recommend.

Chronic Kidney Disease

Chronic Kidney Disease is the gradual loss of kidney function, which seems pretty simple in those terms. It’s actually pretty complex though when you consider the multitude of things that can bring it about. Chronic kidney disease occurs when another disease or condition impairs kidney function, making the organs worsen over several months to a year (ish).

Potential causes include diabetes (both type 1 and type 2), high blood pressure, recurrent kidney infection, polycystic kidney disease, prolonged obstruction of the urinary tract (from something like an enlarged prostate or the kidney stones we just talked about), interstitial nephritis, and more.

Symptoms tend to develop over time, and they include nausea, vomiting, appetite loss, fatigue, sleep problems, muscle cramps, dry or itchy skin, and chest pain (all of which can be confused with a host of other illnesses and conditions). If you catch it quickly enough, chronic kidney disease can be controlled by treating the cause. But because it’s not particularly easy to diagnose, it can often lead to end-stage kidney failure, which is fatal without dialysis or a kidney transplant.

Chronic kidney disease affects 1 in 7 adults in the US. It’s even more common for people with pre-existing conditions, with 1 in 3 diabetics and 1 in 5 people with high blood pressure developing kidney disease.

Urinary Tract Infections (UTI)

Urinary Tract Infections, sometimes called Cystitis, are infections that occur in your kidneys, ureters, bladder, or urethra–pretty much any part of your urinary system. They are caused by bacteria that enter the urinary tract through the urethra, multiplying rapidly when they reach the bladder (see the urethra as it connects to the bladder below). UTI’s are fairly common and generally just painful and annoying when they’re isolated to the bladder and urethra (which they tend to be). They can be treated pretty quickly and easily with antibiotics.

Symptoms include a burning sensation when urinating, a persistent urge to urinate (insult to injury), passing small and frequent amounts of urine, pelvic pain, and urine that appears cloudy, red, bright pink, or coca-cola colored (sorry if we ruined coke for you there, but it’s better you know than not).

Though usually not that dangerous, the bacteria that causes UTIs has a tendency to climb higher and higher in your urinary tract and can eventually reach the kidneys, leading to a kidney infection that can have some serious consequences (which is why it’s important to treat a UTI as soon as possible).

Kidney Infections

On the note of UTIs, let’s talk about one of the things they can cause–kidney infections. A Kidney Infection, also known as Pyelonephritis, is a type of urinary tract infection that reaches one or both of your kidneys.

Symptoms include fever, chills, frequent urination, a persistent urge to urinate, burning when urinating, nausea and vomiting, abdominal pain, opus or blood in your urine, and mild to severe back, side, or groin pain. In other words, it’s not fun!

If you think you have a kidney infection, go get it checked out immediately (we can’t stress this enough). If not treated, it can lead to permanent kidney damage or a life-threatening infection called blood poisoning (which is exactly as scary as it sounds) if the bacteria spreads to your bloodstream


Glomerulonephritis, pronounced glow-mer-u-low-nuh-fry-tis (even we had to look that up) is the inflammation of the Glomeruli –tiny little capillaries in your kidneys whose job is to filter and remove excess fluid, electrolytes, and waste from your blood and transfer them to your urine. There are two types of this disease–chronic and acute.

  • Acute Glomerulonephritis develops suddenly and rapidly. It can sometimes get better on its own, but if it doesn’t, it can lead to acute kidney failure, chronic kidney disease, high blood pressure, or nephrotic syndrome if you don’t get it treated quickly and correctly. Early symptoms include puffiness of the face in the morning, blood in urine, or urinating less frequently than usual.

  • Chronic Glomerulonephritis develops silently over several years with no symptoms, often leading to complete kidney failure. Early signs can include blood in urine, high blood pressure, swelling of the ankles or face, frequent nighttime urination, or foamy urine.



There are tons of conditions that can cause glomerulonephritis (which is almost as hard to spell as it is to say). They include bacterial infections like strep throat and staph, viral infections like HIV and hepatitis B and C, vasculitis in the forms of polyarteritis or granulomatosis, and immune diseases like lupus, Goodpasture’s syndrome, and Berger’s disease. Early diagnosis is key, so keep an eye out for the signs and symptoms that can indicate the onset of this disease.

✅ Conclusion

It’s pretty clear that excretory diseases are no joke. Your urinary tract, and especially your kidneys, are super important parts of your body and they should be taken care of. Make sure you’re drinking your water, watching your blood pressure, limiting alcohol and caffeine, using the bathroom often as needed, and taking note of underlying conditions that can cause excretory diseases. We hope you learned something today about a few of the diseases that can affect your excretory system today, and encourage you to take a look at the practice FAQs below to check your understanding.


1. Name three common diseases of the excretory system.

Common diseases of the excretory system include kidney stones, chronic kidney disease, urinary tract infections, kidney infections, and glomerulonephritis, among others.

2. What are the four parts of the urinary system?

The kidneys, ureters, bladder, and urethra.

3. Name three of the six waste products that are removed from your body by the excretory system.

Excess water, salts, nitrogen, toxins, medications, or drugs.

4. What kind of infection can lead to a kidney infection?

A urinary tract infection.

5. Can kidney stones lead to chronic kidney disease?

Yes. Because chronic kidney disease can be caused by prolonged obstruction of the urinary tract, kidney stones lodged in your ureter can instigate its onset.

6. Name two organs outside of the urinary system which are involved in excretion.

The skin, large intestine, liver, or lungs.

7. The inflammation of what structure in the kidneys causes glomerulonephritis?

The glomeruli.

Bonus: pronounce glomerulonephritis in one try. ;).

We hope you enjoyed studying this lesson and learned something cool about the Excretory System Diseases! Join our Discord community to get any questions you may have answered and to engage with other students just like you! Don’t forget to download our App to experience our fun, VR classrooms – we promise, it makes studying much more fun! 😎

Continue your learning journey

Learn more about Kidneys

Learn more about other organs: Digestive System Organs & Respiratory System Organs


  1. Disorders of Excretory System- Causes, Symptoms, Treatments and Prevention. https://www.embibe.com/exams/disorders-of-excretory-system/amp/. Accessed 25 Nov, 2021.

  2. Excretory System Diseases. https://flexbooks.ck12.org/cbook/ck-12-middle-school-life-science-2.0/section/11.39/primary/lesson/excretory-system-problems-ms-ls/. Accessed 25 Nov, 2021.

  3. Disorders of the Excretory System. https://www.toppr.com/guides/biology/excretory-products/disorders-of-the-excretory-system/. Accessed 25 Nov, 2021.


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