Cat Tips

The Silent Health Risk Many Cat Parents Miss

Your cat may look perfectly fine while a hidden health threat quietly strains their eyes, kidneys, brain, and heart. Here is what every cat parent should know.

Reviewed by Dr. Elizabeth Hardoon

May 22, 2026 • 5 min read

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STORY AT-A-GLANCE

Feline hypertension often develops quietly. Many cats show no obvious signs until high blood pressure has already begun damaging the eyes, kidneys, brain, or heart
Older cats face the highest risk, especially those with chronic kidney disease or hyperthyroidism, the two conditions most commonly linked to rising blood pressure
Warning signs may include sudden blindness, dilated pupils, vomiting, weight loss, increased thirst, and unusual vocalizing or restlessness
Blood pressure checks are simple and painless, but stress during vet visits can skew readings, which is why some cats need repeat measurements
With prompt treatment, ongoing monitoring, and management of the underlying disease, many cats live comfortably for years after a hypertension diagnosis

Most cat parents know how to watch for limping, diarrhea, or trouble breathing. Those are the kinds of problems that signal something is wrong and prompt a visit to the vet. But one of the most dangerous health conditions affecting older cats does not show obvious signs. Instead, it develops quietly and causes no dramatic disruptions to your cat’s daily routine. That invisible threat is feline hypertension, and it is far more common in cats than most pet parents realize.

The Hidden Danger of Feline Hypertension

Hypertension is simply high blood pressure, Which means the blood moving through your cat’s arteries puts high pressure on the surrounding artery walls. This high pressure over time can cause smaller blood vessels with thinner walls to burst or rupture and cause bleeding. The bleeding may be miniscule but eventually can lead to organ damage. Organs most subject to damage include the eyes and kidneys which both rely on their many small blood vessels for normal function, as well as the brain and heart.

When symptoms do show up, they can appear to happen suddenly and often reflect the organs already under strain. These may include:^1,2

Sudden blindness
Bumping into furniture or missing jumps
Fixed or dilated pupils
Blood in the eye
Disorientation or seeming confused
Restlessness or increased vocalizing
Stumbling, poor balance, or back leg weakness
Vomiting
Decreased appetite
Weight loss
Lethargy
Increased thirst
Larger urine clumps in the litter box
Seizures in more severe cases

The eye changes are often the most dramatic because the tiny blood vessels in the retina are especially fragile, and if those vessels rupture the retina can detach and cause sudden blindness. In some cats’ blindness is the first clear sign that anything is wrong.

Which Cats Are Most at Risk and Why

Age is the single biggest risk factor. Feline hypertension is primarily a disease of senior and geriatric cats, and the older your cat gets, the more vigilant you need to be.

Chronic kidney disease (CKD) is the most common underlying condition, present in up to 74% of cats diagnosed with hypertension.³ As a cat ages, the kidneys gradually accumulate scar tissue and shrink. Filtering blood becomes harder, pressure backs up into the arteries, and hypertension follows. Roughly 60% of cats in late-stage kidney failure have it,⁴ but importantly, cats in the initial stages of CKD can develop high blood pressure too, long before kidney disease is obvious.

Hyperthyroidism, another common condition in older cats, affects about a quarter of hypertensive cats. When the thyroid gland overproduces hormones, the heart compensates by pumping harder and faster, and blood pressure climbs as a result. The good news here is that hyperthyroidism is curable, and controlling it often brings blood pressure back down without additional medication.⁵

A handful of other conditions also carry an elevated risk, including diabetes mellitus and Cushing's disease as well as rare diseases such as hyperaldosteronism and pheochromocytoma. Certain medications, particularly prednisolone and phenylpropanolamine may contribute to hypertension, so it is worth mentioning any current medications to your vet when blood pressure is being assessed.⁶

How High Blood Pressure Is Diagnosed in Cats

Getting your cat's blood pressure measured is simpler than you might expect. A small cuff is placed on their leg and inflated while the monitor takes the reading. The procedure is painless and for a calm cat, takes just a few minutes. The reading works the same way as a human blood pressure measurement, with the key number being systolic blood pressure (the top number). Here is a quick reference for what those numbers mean:⁷

Normal — Under 150 mmHg
Prehypertension — 151 to 180 mmHg
Hypertension — 181 to 200 mmHg
Severe hypertension — Over 200 mmHg

One important caveat: Many cats are stressed at the vet, which temporarily elevates their blood pressure, a phenomenon called “white coat syndrome.” If your cat's reading falls in the borderline range, your vet will likely wait, let them settle, and recheck their levels rather than jumping straight to medication.⁸

For cats that are genuinely difficult to calm in a clinic setting, a mobile vet who can take readings at home may give more accurate results. The International Society of Feline Medicine recommends the following blood pressure screening schedule:⁹

Healthy senior cats (7 to 10 years) — Every 12 months
Healthy geriatric cats (11+) — Every six to 12 months
Cats with CKD, hyperthyroidism, or signs of organ damage — At diagnosis, then every three to six months

Managing Hypertension — How to Help Your Cat Thrive

A hypertension diagnosis is serious, but it does not mean your cat’s good years are over. With steady care and the right plan, many cats continue to live comfortably for years. If your cat’s blood pressure is only mildly elevated and no organ damage is present, your veterinarian may focus first on treating the underlying condition and will continue to monitor your pet’s blood pressure. Here are some additional ways to manage feline hypertension:

Feed them a healthy diet — A species-appropriate, low-glycemic diet helps keep your cat at a healthy weight. Raw or fresh foods are best. Excess weight puts added strain on the cardiovascular system and may make high blood pressure harder to control.^10,11 For overweight cats, portion-controlled meals and daily movement help too.
Consider targeted supplementation — Omega-3 fat, particularly from high-quality krill oil, has been shown to help improve heart health in cats.¹² Olive leaf extract is another option worth discussing with a vet, as it has been linked to reductions in both blood pressure and blood sugar levels.¹³ There are also various herbal supplements that can be used to stabilize blood pressure. Work with your holistic vet to see what formulas would be best for your cat.
Keep their environment stable — Because stress can drive blood pressure even higher, your cat will do best with a routine that feels steady and predictable. Regular feeding times, fewer disruptions, and a calm, enriching environment help reduce added strain on a cat already dealing with hypertension.
Reduce your cat’s anxiety — Calming cat safe essential oils, pheromone sprays and diffusers can help reduce your cat’s overall anxiety and in turn help with their blood pressure. Some cats will also respond to acupuncture treatments which can help with anxiety as well as the underlying cause of hypertension.

Hypertension is a condition that is managed over time, not one that is fixed in a single visit. Follow-up blood pressure checks, along with necessary lab work will show whether the plan is working and if it needs to be adjusted. With some minor changes and adjustments, your cat can maintain an excellent quality of life, even with hypertension.