I remember a patient, Mr. Henderson, coming in once, looking worried. He’d always been pretty regular, you know? But for the past day or so, he just… wasn’t peeing. Or hardly at all. He felt bloated, a bit off, and increasingly anxious. That’s a big red flag for us doctors. When your body isn’t making urine, or very little of it, we call that anuria.
It’s one of those things we take very seriously, and right away. Think of it: your kidneys are your body’s amazing filters. They work day and night to clean out waste products and extra fluid, packaging them up as urine. If that process stops, or slows to a trickle, those wastes and fluids start to build up. And that can get dangerous, fast. Normally, an adult makes over about half a litre (or a pint, around 17 ounces) of urine a day. With anuria, we’re talking less than 100 millilitres (about 3.3 ounces) a day, or even none at all. It’s a true medical emergency.
What is Anuria, Exactly?
So, anuria isn’t just “peeing less.” It’s the most severe form of what we call oliguria (which means low urine output). When we say anuria, we mean your kidneys are either not producing urine, or something is blocking it from getting out.
Why does this happen? Well, it’s not always straightforward. There are a few main ways things can go wrong.
Signs You Might Be Experiencing Anuria (Beyond Not Peeing)
The most obvious sign, of course, is that you’re not peeing much, or at all. But because anuria is often linked to other underlying issues, you might also notice:
- Swelling, especially in your legs, ankles, or feet. We call this edema.
- Feeling unusually weak or tired.
- Dizziness or lightheadedness.
- A feeling like you’re about to faint (that’s presyncope).
- Sometimes, if an infection is involved, you might have a fever.
- If it’s a blockage, you might feel pain in your lower back or abdomen.
If you’re noticing you can’t pee or are peeing very little, and you have any of these other symptoms, please don’t wait. It’s time to get checked out immediately.
What Causes Anuria?
Okay, let’s talk about why this might be happening. I tend to think of the causes in a few buckets:
Problems Before the Kidneys (Prerenal Causes)
This is when your kidneys aren’t getting enough blood or fluid to do their job. Think of it like a factory not getting its raw materials. This can happen due to:
- Extreme dehydration: Not drinking enough, or losing a lot of fluids from vomiting or diarrhea.
- Significant blood loss.
- A severe bacterial infection spreading through your body (sepsis).
- Hypovolemic shock: A dangerous drop in blood volume.
- Acute heart failure or worsening congestive heart failure: When the heart can’t pump blood effectively.
- Liver failure.
Problems Within the Kidneys (Renal Causes)
Here, the kidneys themselves are damaged or not filtering properly.
- Shock (from any cause) can damage kidney tissue.
- Infections directly affecting the kidneys.
- Certain medications: This is a big one we watch for. Drugs like NSAIDs (ibuprofen, naproxen), some antibiotics, ACE inhibitors and ARBs (blood pressure meds), and certain chemotherapy drugs can sometimes harm the kidneys.
- Chemical intoxication: Inhaling things like gasoline or certain solvents.
- Autoimmune diseases: Conditions where your body’s immune system mistakenly attacks your kidneys.
Problems After the Kidneys (Postrenal Causes)
This is when urine is being made, but it can’t get out of your body due to a blockage.
- Bladder outlet obstruction: Something blocking the exit from your bladder.
- Kidney stones: Especially if they block the ureters (the tubes from kidneys to bladder) on both sides, or in someone with only one working kidney.
- An enlarged prostate gland (we call this benign prostatic hyperplasia, or BPH) in men.
- Certain cancers, like gynecological cancers or lymphoma, that can press on the urinary tract.
One of the common scenarios we see leading to anuria is something called Acute Kidney Injury (AKI), which used to be called acute kidney failure. It’s a sudden drop in kidney function.
How We Figure Out What’s Going On: Diagnosing Anuria
When you come in saying you’re not peeing, we’ll start by talking. I’ll want to know:
- What have you been drinking, and how much?
- When did you last pee normally?
- Have you had trouble peeing before?
- Any swelling, blood in your urine (hematuria), or unusual tiredness (fatigue)?
Then, we’ll likely need some tests to get a clearer picture of your anuria. These often include:
- Kidney function tests: These are usually blood tests (checking things like creatinine and BUN) and urine tests (a urinalysis) if you are producing even a tiny bit of urine.
- Imaging tests: An ultrasound of your kidneys and bladder is often the first step to look for blockages or structural problems. Sometimes a CT scan or MRI might be needed for more detail.
- Occasionally, a kidney biopsy (where a tiny piece of kidney tissue is taken for examination by a pathologist – a doctor who specializes in looking at tissues under a microscope) might be needed if we suspect a specific kidney disease.
- A kidney (renal) scan can show us how well blood is flowing to your kidneys and how they’re functioning.
Getting Things Flowing Again: Anuria Treatment
First things first: you can’t treat anuria at home. This needs medical attention, and quickly.
The treatment for anuria really depends on what’s causing it. Our first job is often to deal with any immediate life-threatening issue.
- If it’s something like severe heart failure, sepsis, or shock, we’ll focus on treating that underlying condition.
- If your kidneys are severely damaged, you might need dialysis. This is a treatment that does the job of your kidneys by cleaning your blood. In the long term, a kidney transplant might be an option for some.
- If there’s a blockage, we need to relieve it. This might involve:
- Placing a catheter (a thin tube) to drain urine from your bladder. This could be a Foley catheter (through the urethra) or sometimes a suprapubic catheter (directly into the bladder through the lower belly).
- Using ureteral stents, which are tiny tubes placed inside the ureters to hold them open.
- If you’re dehydrated, we’ll get fluids into you, either by having you drink or through an IV (intravenous) line directly into a vein.
We’ll always discuss all the options and what makes the most sense for your specific situation.
What to Expect and How to Prevent Anuria
The outlook really hinges on what’s causing the anuria and how quickly we can start treatment. Some causes are easier to fix than others. That’s why getting seen fast is so important.
If you have ongoing conditions like diabetes or heart failure, it’s crucial to follow your doctor’s advice carefully. This includes:
- Watching what you eat and drink.
- Keeping an eye on your weight.
- Knowing the signs of fluid retention or swelling.
- Taking your medications exactly as prescribed.
And if you’re sick with something that causes vomiting or diarrhea, make sure you’re drinking plenty of fluids to avoid dehydration.
Take-Home Message: Key Points About Anuria
Here’s what I really want you to remember about anuria:
- Anuria means you’re producing very little (less than 100 mL/day) or no urine.
- It’s a serious medical emergency. Don’t wait to seek help.
- Causes can range from dehydration and infections to medication side effects, blockages, or serious conditions like heart or kidney failure.
- Diagnosis involves a careful history, physical exam, and tests like blood work, urine tests (if possible), and imaging.
- Treatment targets the underlying cause and might include fluids, medications, procedures to relieve blockages, or dialysis.
- Managing chronic conditions well and staying hydrated can help prevent some causes of anuria.
When to Call Your Doctor
If you have a condition that affects your kidneys or heart, call your doctor right away if you notice you’re not peeing as much as usual, especially if you’re drinking fluids. Also, pay attention to any changes in your urine, like if it becomes much darker.
You’re not alone in this. We’re here to help figure things out and get you the care you need.
