Why Is My Cat Peeing a Lot？3 Serious Causes & Signs

Key Takeaways: Cat Peeing a Lot

• It is a Major Medical Sign: A sudden increase in urine volume (Polyuria) is almost always a sign of internal disease, not a behavioral quirk.

• The Big Three Causes: Kidney Disease (CKD), Diabetes, and Hyperthyroidism are the most common culprits.

• Do Not Be Fooled: A cat can pee a lot while acting normal. Do not wait for them to look sick; the urine change is the early warning.

• Volume vs. Frequency: There is a big difference between peeing large amounts (Systemic Disease) vs. peeing frequently in small drops (UTI/Blockage).

• Emergency Flags: If they stop eating, vomit, or become lethargic, seek immediate veterinary care.

Is It Volume or Frequency? (Read This First)

 

 

Before you assume your cat has kidney failure, look closely at the litter box. “Peeing a lot” can mean two very different things medically, and distinguishing them is key to diagnosis.

Symptom	What It Looks Like	Potential Causes
High Volume (Polyuria)	Giant clumps (tennis ball size); “Flooding” the box; Peeing large puddles at once.	Kidney Disease, Diabetes, Hyperthyroidism.
High Frequency (Pollakiuria)	Going to the box every 10 mins; Squeezing out tiny drops; Straining.	UTI, Bladder Stones, Cystitis, Blockage.

• Note: If your cat is straining and producing no urine, go to the ER immediately. This is a fatal urinary blockage.

• This article focuses on HIGH VOLUME (Polyuria).

 

 

Why Is My Cat Peeing So Much?(The Big Three)

 

When a cat’s body produces an excessive amount of urine, it’s because an internal process is out of balance. This is almost always linked with “polydipsia,” or excessive thirst. They are peeing a lot because they are drinking a lot—or they are drinking a lot because they are peeing a lot. It’s a cycle driven by disease.

Here are the most common physiological reasons:

• Chronic Kidney Disease (CKD): This is a very common cause, especially in older cats. Healthy kidneys concentrate urine, reabsorbing water back into the body. Diseased kidneys lose this ability. They can’t stop water from being flushed out, so the cat produces huge volumes of dilute, pale urine. They drink more and more to fight off the resulting dehydration.
• Diabetes Mellitus: In diabetic cats, there is too much glucose (sugar) in the blood. The kidneys try to filter this sugar out, and water follows the glucose into the urine, leading to a high volume of pee. You may also notice your cat has a ravenous appetite but is losing weight.
• Hyperthyroidism: An overactive thyroid gland (common in senior cats) speeds up the entire body, including the metabolism and blood flow to the kidneys. This increases urine production and also makes the cat intensely thirsty. Other signs include weight loss, hyperactivity, and a rough-looking coat.
• Urinary Tract Infection (UTI) / Bladder Crystals: While often causing frequent, small urinations, a severe infection or irritation can sometimes lead to a general loss of bladder control or increased urgency, which may be perceived as “peeing a lot.”
• Liver Issues: Liver disease can interfere with the body’s water regulation, leading to increased thirst and urination.
• Medication-Related Causes: Drugs like corticosteroids (steroids) or diuretics (often for heart conditions) are designed to increase urination.

The Acting Normal Trap:My cat is peeing a lot but acting normal. Should I worry?

 

YES. This is the most dangerous trap for owners. Cats are masters of disguise. In the early stages of Kidney Disease or Diabetes, the only symptom is increased thirst and urination. They will still eat, play, and cuddle.

• The Reality: By the time a cat starts “acting sick” (vomiting, hiding, refusing food), roughly 75% of kidney function may already be lost. The increased urine is the sickness. Do not wait for them to crash.

Special Scenarios: Kittens & Female Cats

 

Why Is My Kitten Peeing a Lot?

Unlike senior cats, kittens rarely get the “Big Three.” If a kitten is peeing large volumes:

• Diet: Kittens on a wet-food-only diet naturally pee more than kibble-fed cats. This is healthy.

• Congenital Issues: Rare conditions like kidney dysplasia.

• Worms: Heavy parasitic burdens can sometimes affect nutrient and fluid absorption.

Female Cat Has Large Volume of Urine?

If you have an unspayed female cat, excessive urination and thirst can be a sign of Pyometra (a life-threatening uterus infection).

• Watch for: Vaginal discharge, a swollen belly, or fever. This requires emergency surgery.

Cat Peeing a Lot and Not Eating

This combination is a medical emergency. A cat peeing a lot and not eating is a sign that the underlying disease has progressed to a critical, systemic stage.

• Advanced Kidney Disease: When the kidneys fail, toxins (like urea) build up in the bloodstream. This condition, called uremia, causes severe nausea, vomiting, and a complete loss of appetite.
• Severe Diabetes (DKA): Unmanaged diabetes can lead to Diabetic Ketoacidosis (DKA), a life-threatening complication where the body, starved for energy, starts burning fat and produces toxic byproducts called ketones. This causes vomiting, lethargy, and a loss of appetite.
• Urinary Infection: A severe kidney or bladder infection can cause fever, pain, and nausea, making the cat refuse food.

If your cat is showing both of these symptoms, they need to see a veterinarian immediately.

Cat Peeing a Lot but Not Drinking

This symptom is confusing. You see a cat peeing a lot but not drinking from their water bowl. How is this possible?

There are two main explanations:

• They ARE Drinking—From Food: This is the most common and benign reason. If you recently switched your cat to a wet-food diet, they are getting the vast majority of their hydration from their meals. They may rarely, if ever, visit the water bowl. Their increased urine output is healthy and normal in this context.
• They Are Medically Unable: This is the serious scenario. The cat’s kidneys have completely lost the ability to concentrate urine and are just passively flushing water out. The cat should be desperately thirsty but may be too sick, nauseous, or lethargic (from kidney failure or another disease) to get up and drink. This is an advanced, critical stage of illness.

Observe your cat’s total moisture intake. If they are on dry food and truly not drinking but still peeing a lot, it is an emergency.

Emergency Red Flags: When to Rush to the Vet？

 

If your cat is peeing a lot AND shows any of these signs, the disease has progressed to a critical stage:

• Not Eating: Suggests nausea from kidney toxins (uremia) or diabetic crisis (ketoacidosis).

• Vomiting: A sign of severe systemic illness.

• Extreme Lethargy: The cat is too weak to move.

• Peeing a Lot But NOT Drinking: This suggests the kidneys are failing to hold any water, and the cat is too sick to drink. This leads to rapid, fatal dehydration.

How to Monitor & What to Expect at the Vet？

 

You cannot treat this at home, but your data helps the vet.

What to Track at Home:

1. Clump Check: Take a photo of the scooped litter to show the clump size.

2. Water Audit: Fill the water bowl to a marked line and see how much is gone in 24 hours.

At the Vet Clinic: Your vet will run a Senior Blood Panel and a Urinalysis.

• Urinalysis is non-negotiable: It checks “Specific Gravity” (how concentrated the pee is).

  • High Gravity: Dehydration but working kidneys.

  • Low Gravity (Dilute): Kidney failure or hormonal disease.

Frequently Asked Questions

Q: Can stress cause cats to pee large amounts?

A: Usually, no. Stress typically causes frequency (peeing often in small amounts) or inappropriate urination (peeing on the bed). It rarely causes the production of large volumes of urine.

Q: Did switching to wet food make my cat pee more?

A: Yes! And this is good. Wet food is ~78% water. A cat eating wet food will naturally produce more urine than a cat on dry kibble. If the cat is healthy and the urine is pale yellow (not clear like water), this is normal.

Q: Can I just treat this with home remedies?

A: No. Diseases like Diabetes and Hyperthyroidism require medication (Insulin or Methimazole). Kidney disease requires prescription diets. Home remedies cannot fix organ failure.

Conclusion