Why is my older cat weeing so much more than usual?

In older cats this is commonly linked to hyperthyroidism, kidney disease or diabetes, all of which become more common with age and typically come with increased thirst alongside the increased urination. A vet can run blood and urine tests to identify which, if any, is behind it.

Is it normal for a cat to drink and wee more as they age?

A gradual, mild increase can happen with age, but a noticeable or sudden increase in either drinking or weeing is not something to assume is simply ageing. It is common enough to have an underlying, treatable cause that a vet check is always worthwhile.

How urgent is it if my cat is weeing a lot but seems otherwise fine?

It still warrants a vet appointment reasonably soon rather than being left indefinitely, since conditions like diabetes and kidney disease can be well established before a cat shows other obvious signs of being unwell. Catching it earlier generally makes ongoing management considerably easier.

Cat weeing a lot

A cat weeing noticeably more than usual, especially if they also seem to be drinking more, is a symptom that genuinely needs a vet appointment rather than watching and waiting. Increased urination in cats is often linked to conditions like diabetes, kidney disease or an overactive thyroid, particularly in older cats, and catching the underlying cause early generally makes a real difference to how well it can be managed.

Usually not urgent

This is common and often manageable at home — but see a vet if it persists, gets worse, or comes with other changes.

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What increased urination commonly looks like

Owners usually notice it first through the litter tray — larger or more frequent wet patches, needing to change or clean the tray more often than usual, or a cat asking to go outside to toilet more frequently than before. It is often paired with drinking noticeably more water than usual, which is easy to miss if you don't top up the water bowl at a fixed level to compare against.

Some cats also start weeing outside the litter tray as the volume increases beyond what they are used to managing, which can look like a behavioural issue at first glance but is worth considering alongside a physical cause, particularly in a cat with no previous history of toileting problems.

Common underlying causes

In older cats, an overactive thyroid gland (hyperthyroidism), chronic kidney disease and diabetes are among the more common causes of a genuine increase in urination, each affecting how the body processes fluid and waste in different ways. All three become more common with age and often present with increased thirst alongside the increased weeing.

In younger cats, a urinary tract infection or other bladder issue is a more likely explanation, sometimes alongside straining, blood in the urine, or clear discomfort while toileting rather than simply weeing more. Stress can also affect litter box behaviour, but a genuine increase in the actual volume of urine produced points more toward a physical cause than a behavioural one.

Red flags that need attention now

Weight loss despite a normal or increased appetite, noticeably increased thirst, lethargy, vomiting, or a cat who seems generally unwell alongside the change in urination are all signs that point toward one of the more significant underlying conditions rather than something minor. Blood visible in the urine or obvious straining and discomfort also need prompt attention.

Any of these alongside increased urination in an older cat especially should move this from a routine, book-when-convenient appointment to one arranged as soon as reasonably possible.

When to see a vet

Book an appointment as soon as you notice a genuine, sustained increase in how much your cat is weeing, particularly if it comes with increased thirst or any of the red flags above. A vet will typically want to run blood and urine tests to identify the underlying cause, since diabetes, kidney disease and hyperthyroidism are managed quite differently from one another despite looking similar at first.

While a clean, easily monitored litter tray and a reliable water source are sensible things to have in place either way, they are tools for keeping an eye on your cat while you arrange that appointment, not a substitute for it.

What helps while you wait for the appointment

A single, uncluttered litter tray that is easy to check daily makes it far simpler to notice a genuine change in volume rather than relying on memory, and it also gives your vet more useful information if they ask how the toileting has changed over the past week or two. Some owners find it helpful to briefly note how often the tray needs changing in the days before the appointment.

Make sure fresh water is always available and easy to reach, since a cat drinking more will need somewhere accessible to do it, and a sudden restriction on water is never the right response to increased thirst — that thirst is very likely the body's own response to what is going on internally, and interfering with it can do more harm than good. None of this changes the underlying condition, but it keeps your cat comfortable and gives the vet a clearer picture once you are seen.

What can help

Things we stock that owners commonly use alongside a vet’s advice — not a substitute for it.

304 Stainless Steel Pet Water Fountain 3.2L

A 3.2L 304 stainless steel fountain that automatically circulates water through a gooseneck spout to keep it fresh. A visible side window shows the water level, so cats and dogs always have clean water.

£36.99

Sensor Cat Water Fountain 2.5L

A 2.5L cat fountain that flows when your cat approaches, keeping water fresh and tempting. A clear level window shows when to refill, and the generous tank meets one cat's needs for several days.

From£43.99

Automatic Cat Water Fountain

A clear automatic pet water fountain with a tap-style spout that circulates fresh, filtered water to encourage your cat to drink. The near-silent pump and large transparent tank let you check water levels at a glance.

£44.99

Common questions

Why is my older cat weeing so much more than usual?: In older cats this is commonly linked to hyperthyroidism, kidney disease or diabetes, all of which become more common with age and typically come with increased thirst alongside the increased urination. A vet can run blood and urine tests to identify which, if any, is behind it.
Is it normal for a cat to drink and wee more as they age?: A gradual, mild increase can happen with age, but a noticeable or sudden increase in either drinking or weeing is not something to assume is simply ageing. It is common enough to have an underlying, treatable cause that a vet check is always worthwhile.
Can stress make a cat wee more?: Stress can affect litter box behaviour and where a cat chooses to toilet, but a genuine increase in the actual volume of urine produced points more toward a physical cause, such as a urinary or hormonal condition, than stress alone.
How urgent is it if my cat is weeing a lot but seems otherwise fine?: It still warrants a vet appointment reasonably soon rather than being left indefinitely, since conditions like diabetes and kidney disease can be well established before a cat shows other obvious signs of being unwell. Catching it earlier generally makes ongoing management considerably easier.

Sources

Written against guidance published by UK veterinary and welfare organisations. Always confirm specifics with your own vet.

Written by Matt Garnett, who runs Giddy Pets and is a lifelong pet owner — not a vet. This is general information, not veterinary advice, and it cannot replace an examination by the vet who knows your animal. How we write these guides.