Why Is My Cat Drinking and Peeing More Than Usual?

A cat drinking and peeing a lot may be responding to differences in food moisture, environment or medication, but a persistent increase in both thirst and urine volume can also occur with medical conditions such as chronic kidney disease, diabetes and hyperthyroidism. These symptoms are often called polydipsia, meaning increased drinking, and polyuria, meaning increased urine production. They are observations, not diagnoses.

An equally important distinction is how the cat is urinating. Large litter clumps suggest increased urine volume, while repeated litter-box visits with straining and only drops or no urine can indicate lower urinary tract disease or obstruction. A blocked urethra is a true emergency, and male cats are at greater risk because their urethra is longer and narrower.

Direct Answer

If your cat is genuinely drinking more and producing more urine than usual, arrange veterinary assessment rather than assuming the change is harmless. Kidney disease, diabetes, hyperthyroidism, medication effects and other systemic problems are among the possibilities. If your cat repeatedly strains to urinate but produces little or no urine, seek immediate veterinary care, especially for a male cat.

Increased Thirst Versus Normal Variation

Start by asking whether there has been a real change from your cat’s normal pattern.

A cat may appear to drink more because:

a new bowl is easier to observe
the cat has switched to drier food
you recently began measuring the water
another pet previously shared the same bowl
household routines have changed

Water comes from both drinking and food. Cornell notes that a cat eating moisture-rich wet food may drink noticeably less from a bowl than one eating dry food because part of its daily water intake already comes from the diet.

A persistent increase that cannot be explained by feeding or measurement changes is more useful medically than a single unusually long drink.

Food Moisture

Food type can make a large difference to what you see at the water bowl.

Cornell reports that canned foods typically contain roughly 70 to 80 percent water, while cats fed dry diets obtain more of their water through drinking. A switch from wet to dry food can therefore make bowl drinking increase without necessarily meaning the cat’s total water intake has become abnormal.

When monitoring thirst, record both:

how much the cat drinks
whether the diet is wet, dry or mixed

Use Pawnium’s How Much Water Should a Cat Drink? guide for the detailed hydration discussion rather than diagnosing excessive thirst from bowl volume alone.

Hot Weather

Cats need water for normal body functions, including temperature regulation. During hot weather, access to fresh water becomes particularly important, and Cornell specifically recommends ensuring that cats always have water available during warm conditions.

A modest change in drinking during hotter conditions can therefore have environmental context.

However, do not use weather as the explanation for a persistent major increase in drinking and urination, especially when weight, appetite, activity or urine output are also changing.

Activity

Changes in activity can also change day-to-day water use.

A cat that is spending more time playing, roaming or being active may not drink exactly the same amount every day. Water intake is influenced by intake and losses rather than being a perfectly fixed number.

Activity becomes less convincing as the sole explanation when:

thirst remains markedly increased
litter clumps are consistently much larger
weight is falling
vomiting occurs
appetite changes

In those situations, veterinary investigation is more appropriate than assuming the cat is simply more active.

Medication

Medication history matters.

Some drugs can increase thirst or urine production. Cornell specifically lists diuretics among medications that can increase water loss, while Merck notes that systemic glucocorticoids can cause polyuria and polydipsia through effects on water regulation.

Record:

medication name
when it was started
any recent dose change
when increased drinking began

Do not stop prescribed medication on your own. Contact the prescribing veterinarian if the timing suggests a connection.

Kidney Disease

Chronic kidney disease is one important reason a veterinarian may investigate when a cat begins producing larger amounts of urine.

As kidney function declines, the kidneys may become less able to concentrate urine effectively. The cat then loses more water in the urine and may drink more to compensate. Weight loss, reduced appetite, vomiting or lethargy may develop as disease progresses.

This pattern is particularly relevant when a senior cat is drinking more water, but increased thirst in an older cat should not simply be blamed on age. Cornell specifically warns against treating changes in senior cats as inevitable ageing and lists kidney disease, diabetes and hyperthyroidism among conditions that can increase urine production.

Thirst alone cannot diagnose kidney disease.

Diabetes

Diabetes mellitus can cause both increased urination and increased thirst.

Cornell explains that when excess glucose spills into the urine, it draws additional water with it. This can result in increased urine volume, water loss and compensatory thirst. Weight loss despite a good or increased appetite is another common pattern.

However:

increased thirst + increased urination does not diagnose diabetes.

The 2026 AAHA feline diabetes guidelines require evidence of sustained abnormal glucose regulation rather than diagnosis from symptoms alone. Veterinary assessment commonly includes history, examination, blood testing and urinalysis.

Hyperthyroidism

Hyperthyroidism is another condition veterinarians may consider, especially in middle-aged and older cats.

Possible signs include:

weight loss
increased appetite
increased thirst
increased urination
vomiting
diarrhoea
increased activity

Cornell describes these as possible clinical signs, but diagnosis relies on veterinary examination and thyroid-hormone testing.

Do not assume that an older thirsty cat has hyperthyroidism.

The same general pattern overlaps with other diseases.

Other Metabolic or Systemic Conditions

Kidney disease, diabetes and hyperthyroidism are important possibilities, but they are not the only explanations.

Other disorders affecting hormones, electrolytes or the body’s ability to concentrate urine can also produce excessive thirst and urination. For example, Merck lists polyuria and polydipsia among possible findings with hypercalcaemia, hyperaldosteronism and hypercortisolism, although these conditions differ greatly in frequency and clinical presentation.

This is why the symptom pair should trigger investigation rather than an attempt to select one diagnosis from an online list.

Increased Drinking With Weight Loss

Thirst plus unexplained weight loss deserves veterinary assessment.

Possible conditions associated with this combination include:

diabetes
chronic kidney disease
hyperthyroidism

but the symptoms cannot tell you which, if any, is present.

If weight is clearly declining, link to Pawnium’s Why Is My Cat Losing Weight but Still Eating? guide and start recording actual body weight rather than relying only on appearance.

Do not simply increase food while ignoring persistent weight loss and increased thirst.

Increased Drinking With Hunger

Increased thirst together with increased appetite is another useful pattern to report.

Diabetes can cause weight loss despite good appetite together with increased thirst and urination. Hyperthyroidism can also produce increased appetite, weight loss, thirst and increased urination.

Use Pawnium’s Why Is My Cat Always Hungry? guide to document the appetite pattern.

The combination still does not establish either diagnosis.

Increased Drinking With Vomiting

Vomiting can occur alongside several diseases that also affect thirst.

Chronic kidney disease may eventually cause nausea or vomiting, while hyperthyroidism can also include vomiting. In diabetic cats, vomiting together with marked illness and dehydration can signal a more complicated clinical situation that requires veterinary assessment.

Use Pawnium’s Cat Vomit Color Chart to record what the vomit looks like, but do not attempt to diagnose the cause from colour.

Repeated vomiting plus excessive thirst, weakness or appetite loss should not be managed as a hydration issue alone.

Increased Urine Volume

A cat urinating large amounts is producing more total urine than before.

At home, you may notice:

larger litter clumps
heavier litter
more urine in non-clumping litter
the box becoming saturated faster

Kidney disease and diabetes can both increase urine volume through different mechanisms. Hyperthyroidism may also be associated with increased urination.

A large urine volume often goes together with increased drinking because the body is replacing water that is being lost.

Frequent Small Urinations

Frequent litter-box visits are not the same thing as producing a large amount of urine.

Lower urinary tract disease may cause:

repeated attempts to urinate
straining
crying during urination
blood in urine
urinating outside the box
genital licking

A cat may visit the box repeatedly while producing only tiny amounts.

That pattern needs to be distinguished from polyuria because the urgency can be very different.

Difference Between Volume and Frequency

Think about these two patterns separately:

Large Volume

The cat may:

produce noticeably larger clumps
empty a full bladder normally
drink substantially more

This pattern is compatible with increased urine production and may lead a veterinarian to investigate kidney, metabolic or endocrine causes.

Frequent Small Attempts

The cat may:

enter and leave the box repeatedly
squat for a long time
produce tiny spots or no urine
vocalise
lick the genital region
appear distressed

This fits a lower urinary tract pattern and can become an emergency if the urethra is obstructed.

Do not describe repeated straining with only drops of urine as simply “peeing more.”

Male-Cat Urinary Emergencies

Male cats deserve particular caution when they repeatedly attempt to urinate.

Because the male urethra is longer and narrower, male and neutered male cats have a greater risk of urethral obstruction. A blocked cat may make frequent attempts to urinate but produce little or no urine and become increasingly distressed.

Seek Immediate Veterinary Care

If a male cat:

repeatedly strains
makes repeated litter-box visits
produces little or no urine
cries or appears painful
becomes increasingly distressed

treat this as an emergency.

Cornell describes urethral obstruction as an absolute medical emergency requiring immediate treatment.

Do not wait to finish a urine tracker.

Measuring Water Intake

If your veterinarian asks you to quantify drinking, measure rather than guess.

A practical approach is:

Measure how much fresh water you put into the bowl.
Use the same bowl and measurement method.
Measure what remains later.
Record water added during the day.
Note spills or fountain losses.
Record whether wet food is being fed.

Remember that bowl measurements do not capture water contained in food. Cornell notes that wet food can supply a substantial proportion of a cat’s daily water intake.

Use the separate Pawnium How Much Water Should a Cat Drink? guide for normal hydration estimates.

Tracking Litter Clumps

Clumping litter can provide a rough home trend when the same:

litter
box
scoop
cleaning routine

are used consistently.

Record both:

number of clumps + approximate size

A shift from several ordinary clumps to consistently much larger clumps may be useful information for your veterinarian.

But litter clumps are not a precise urine-volume measurement, so they should not replace veterinary testing.

Multi-Cat Household Limitations

Monitoring becomes more difficult when several cats share bowls and litter boxes.

You may not know:

which cat drank the water
which cat produced a large clump
whether one cat is urinating outside the box
whether food moisture differs between cats

Cornell also notes that competition between cats can affect access to water.

If practical and not stressful, temporary separate monitoring may help identify which cat’s drinking or urination has changed.

Do not delay veterinary assessment simply because perfect measurements are impossible.

What Owners Should Record

A useful history includes:

When the change began
Estimated water intake
Wet, dry or mixed food
Number of urine clumps
Approximate clump size
Appetite
Weight
Vomiting
Stool changes
Medication
Activity
Behaviour
Straining
Blood in urine
Urination outside the litter box

Veterinary investigation of diabetes, kidney disease and lower urinary tract problems relies on history combined with examination and appropriate laboratory testing rather than symptoms alone.

Why Water Should Not Be Restricted

Never restrict water because your cat is drinking too much.

When increased thirst is compensating for increased urinary water loss, restricting access can interfere with the cat’s ability to maintain hydration. Cornell emphasises providing cats with ready access to fresh water and specifically notes that conditions such as kidney disease and diabetes can increase water losses.

Do not attempt a home “water deprivation test.”

If a veterinarian needs to investigate abnormal urine concentration or water balance, that belongs under professional supervision.

When Veterinary Testing Is Needed

Arrange veterinary examination when:

increased drinking persists
urine clumps become consistently much larger
weight is falling
appetite changes
vomiting develops
urination changes noticeably
a senior cat develops new thirst
medication timing may be relevant
the cat is urinating outside the box
the cause is not obvious from a short-lived environmental change

Depending on the history, a veterinarian may use blood chemistry, a complete blood count, urinalysis and other targeted testing. Diabetes evaluation requires evidence of sustained abnormal glucose regulation, while thyroid testing and kidney assessment may be added when the pattern warrants them.

Urgent Urinary Warning Signs

Seek urgent veterinary care if your cat:

repeatedly strains but produces little or no urine
cannot urinate
repeatedly enters the litter box without producing a normal amount
cries while attempting to urinate
becomes increasingly distressed
has urinary signs followed by weakness or marked deterioration

These signs are particularly concerning in male cats because urethral obstruction can prevent urine from leaving the bladder and rapidly lead to dangerous fluid and electrolyte disturbances.

Large urine clumps and repeated empty straining are not the same problem.

Learning that distinction is one of the most useful things an owner can do when monitoring urinary changes.

FAQs

Why is my cat suddenly drinking lots of water?

A sudden increase may have environmental, dietary or medication context, but persistent excessive drinking can occur with conditions such as kidney disease, diabetes and hyperthyroidism. Measure the change if practical and arrange veterinary assessment when it continues or occurs with weight, appetite or urinary changes.

Why is my senior cat drinking more water?

Do not assume increased thirst is normal ageing. Kidney disease, diabetes and hyperthyroidism become relevant considerations in older cats and can increase drinking or urine production. Veterinary examination is appropriate for a new persistent change.

Does drinking and peeing more mean my cat has diabetes?

No. Diabetes is one possibility, but kidney disease, hyperthyroidism, medications and other disorders can produce overlapping signs. Diabetes requires diagnostic evidence of sustained abnormal glucose regulation.

What is the difference between peeing more and trying to pee more often?

Peeing more means a larger total urine volume, often noticed as bigger litter clumps. Trying more often may involve repeated squatting with tiny amounts or no urine. The latter can occur with lower urinary tract disease and may represent urethral obstruction.

Should I limit my cat’s water if it is drinking too much?

No. Do not restrict access to water. Increased drinking may be compensating for water being lost through increased urination, and cats should continue to have fresh water available while the cause is investigated.

When is a cat’s urination an emergency?

Repeated straining with little or no urine is an emergency, particularly in male cats. Urethral obstruction can rapidly become life-threatening and requires immediate veterinary treatment.