A healthy cat typically uses the litter box about twice a day for urination. If your cat is visiting the box noticeably more than that, something has changed, and the cause matters. The first step is figuring out whether your cat is producing large volumes of urine each time or making frequent trips with little to show for it, because these two patterns point to very different problems.
Large Volumes vs. Frequent Small Amounts
When cat owners say their cat is “using the bathroom a lot,” they usually mean one of two things, and the distinction is critical. Either the cat is producing large floods of urine on each trip (polyuria), or the cat is making many trips to the box but only passing small amounts, sometimes with visible straining (pollakiuria). Watching your cat’s behavior in and around the litter box for a day or two can help you tell the difference.
Large volumes of urine paired with increased water drinking typically signals a systemic problem: the body is pulling too much water through the kidneys. Frequent small amounts with straining, blood-tinged urine, or crying in the box points to a problem in the bladder or urethra itself. Both need veterinary attention, but the urgency and the likely diagnosis are different.
Conditions That Cause High Urine Volume
The three most common medical reasons a cat starts producing large volumes of urine are chronic kidney disease, diabetes, and hyperthyroidism. All three are especially common in middle-aged and older cats.
In chronic kidney disease, the kidneys gradually lose the ability to concentrate urine. Instead of producing small amounts of concentrated waste, they let large volumes of dilute urine pass through. Cats compensate by drinking more water, so you may notice the water bowl emptying faster than usual. Dilute urine can actually be one of the earliest detectable signs of kidney decline, sometimes showing up before a cat looks sick in any other way.
Diabetes works differently. When blood sugar rises above the kidneys’ filtering threshold, excess glucose spills into the urine and drags water along with it. The result is the same from your perspective: a cat that drinks constantly and floods the litter box. Diabetic cats often lose weight despite eating well, which can be a helpful clue.
Hyperthyroidism, caused by an overactive thyroid gland, speeds up metabolism across the board. It disrupts the kidneys’ normal concentrating ability by changing blood flow patterns within the kidney. Cats with this condition tend to be restless, vocalize more, eat ravenously, and still lose weight. Increased urination is often just one piece of a larger picture of a cat that seems “revved up.”
Bladder Inflammation and Urinary Tract Problems
If your cat is making repeated trips to the box, squatting and straining, producing only drops of urine (sometimes with blood), and possibly crying or meowing, the problem is more likely in the lower urinary tract. This cluster of symptoms falls under feline lower urinary tract disease, or FLUTD, which can have several overlapping causes including infection, inflammation, crystals in the urine, and stress.
The most common form in younger and middle-aged cats is feline idiopathic cystitis, essentially bladder inflammation triggered largely by stress. The bladder wall becomes irritated and sends constant urgency signals even when there’s barely any urine to pass. Possible stress triggers include a recent move, a new pet or person in the household, changes in feeding schedule, or conflict between cats in a multi-cat home. Overweight indoor cats with limited exercise and low water intake are at higher risk.
Actual bacterial urinary tract infections are less common in cats than in dogs, but they do occur, particularly in older cats or those with kidney disease or diabetes. The symptoms look similar to cystitis: frequent attempts, small amounts, sometimes blood.
When Frequent Trips Are an Emergency
One scenario requires immediate veterinary care: urinary obstruction. This happens primarily in male cats because their urethra is narrower. A blocked cat will repeatedly visit the litter box, strain hard, and produce little or no urine. Early signs include vocalization while trying to urinate, small drops of bloody urine, and urinating outside the box. If the blockage isn’t relieved, the cat may vomit, stop eating, become lethargic, and eventually collapse.
If you can gently feel a large, firm, ball-shaped structure in the lower part of your cat’s abdomen, that’s a dangerously full bladder. A complete urinary blockage can become life-threatening within 24 to 48 hours as toxins build up in the bloodstream. This is a true emergency, day or night.
Behavioral Causes to Rule Out
Not every change in bathroom behavior is medical. Cats sometimes increase their visits to the box, or start going outside the box, for behavioral reasons. The pattern helps you tell the difference.
Urine marking is a communication behavior. A marking cat sprays small amounts on vertical surfaces (walls, furniture legs, doorframes) or deposits small puddles in socially significant areas, but continues using the litter box normally for regular urination and defecation. Marking often surfaces when there’s tension between cats in the household. You won’t see straining, blood, or changes in water intake.
Litter box aversion is different again. A cat avoiding the box deposits full-sized amounts of urine or feces on horizontal surfaces, often targeting a specific type of surface like a particular carpet. The cat stops using the box altogether or uses it much less. Common triggers include a dirty box, a new litter brand the cat dislikes, a box in a noisy or high-traffic area, or a painful association if the cat once experienced discomfort while using it.
The key distinction: behavioral issues don’t come with increased thirst, weight changes, or signs of physical discomfort. If your cat is drinking more water than usual or showing any sign of straining, the cause is almost certainly medical.
What to Expect at the Vet
A veterinarian will typically start with a urinalysis, which evaluates how concentrated the urine is, whether there’s glucose, blood, bacteria, or crystals present. Dilute urine points toward kidney disease, diabetes, or hyperthyroidism. Concentrated urine with blood and inflammatory cells suggests a bladder problem.
Blood work usually follows to check kidney values, blood sugar, and thyroid hormone levels. Together, these two tests can identify or rule out the most common causes relatively quickly. If you can, bring a fresh urine sample to the appointment (your vet can tell you how to collect one) since it speeds up the process.
Before your visit, spend a day or two noting specifics: how many times your cat visits the box, whether the clumps are large or small, whether you see straining or blood, how much water your cat is drinking, and any recent changes in the household. For reference, a cat drinking more than about 45 milliliters of water per kilogram of body weight per day is drinking above normal. For an average 10-pound cat, that’s roughly one cup. These details help your vet narrow down the cause faster.