High blood pressure (hypertension) in cats is usually a silent disease that quietly damages the eyes, kidneys, heart, and brain. The first sign many owners notice is sudden blindness from a detached retina. Because it's so often secondary to other illnesses like kidney disease or hyperthyroidism, blood pressure checks are a key part of senior cat care.
Last reviewed: June 2026
What Is Hypertension in Cats?
Hypertension is persistently elevated blood pressure that strains and damages delicate "target organs"—the eyes, kidneys, heart, and brain. In cats it is most often "secondary," meaning it arises as a consequence of another disease rather than on its own. The two most common underlying culprits are chronic kidney disease and hyperthyroidism, both common in older cats.
The danger of feline hypertension is that it usually produces no obvious symptoms until it causes sudden, sometimes irreversible organ damage. As outlined in the AAFP Senior Care Guidelines, 2021, routine blood pressure measurement is recommended for senior cats precisely because the disease is so silent. Because kidney disease is the most common driver, blood pressure assessment is also built into chronic kidney disease management (IRIS CKD Staging Guidelines, 2023).
What Are the Signs of High Blood Pressure in Cats?
Most hypertensive cats show no signs until a target organ is damaged, and the most dramatic presentation is sudden blindness. Owners often discover the problem when a cat bumps into furniture or has widely dilated, unresponsive pupils.
Signs to watch for include:
- Sudden blindness or dilated, fixed pupils
- Bleeding inside the eye or a reddish appearance
- Disorientation, circling, or behavior changes (brain involvement)
- Seizures in severe cases
- Increased thirst and urination (often from underlying kidney disease)
- Weight loss or restlessness (often from underlying hyperthyroidism)
Sudden blindness from retinal detachment is one of the most common ways feline hypertension is discovered, and if caught very early, vision can sometimes be partially restored with prompt blood pressure control.
Why Does It Happen?
Feline hypertension is most often secondary to chronic kidney disease or hyperthyroidism, the two diseases that most commonly affect older cats. Less often, conditions such as diabetes, heart disease, or hormonal tumors raise blood pressure. A smaller number of cats have "idiopathic" hypertension with no detectable underlying cause. As described in Ettinger's Textbook of Veterinary Internal Medicine, the kidneys play a central role both as a cause and a victim of high blood pressure, creating a damaging feedback loop.
Because the disease clusters with other senior-cat illnesses, any cat diagnosed with kidney disease or hyperthyroidism should have its blood pressure monitored.
How Is It Diagnosed and Treated?
Diagnosis requires measuring blood pressure with a cat-appropriate cuff, usually repeated to account for stress ("white-coat" effect), along with an eye exam to check for retinal damage. Vets also screen for underlying kidney, thyroid, and heart disease.
Treatment focuses on lowering pressure and protecting the organs:
- Amlodipine, a calcium-channel blocker, is the mainstay oral medication and works well in most cats
- Treating the underlying disease, such as controlling hyperthyroidism or managing kidney disease
- Regular blood pressure rechecks to fine-tune the dose
- Ophthalmic care if the retina has detached
With medication, blood pressure can usually be brought into a safe range, halting further organ damage. Cats caught before severe damage have an excellent outlook, while those with established blindness or kidney injury have a more guarded prognosis.
When to See a Vet
Call your vet today if:
- Your senior cat bumps into things or seems to have lost vision
- Your cat has known kidney disease or hyperthyroidism and seems "off"
- You notice increased thirst, disorientation, or behavior changes
Go to the ER immediately if:
- Your cat suddenly goes blind or has widely dilated, unresponsive pupils
- You see bleeding inside the eye
- Your cat has a seizure or sudden severe disorientation
- Your cat collapses or becomes unresponsive
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Frequently Asked Questions
What are the signs of high blood pressure in cats?
Most cats show no signs until organ damage occurs, and the most striking sign is sudden blindness from a detached retina—dilated pupils that don't respond to light. Other clues include disorientation, circling, seizures, or signs of the underlying disease such as increased thirst from kidney disease. Because it's so silent, screening senior cats is essential.
Can a cat recover vision after hypertensive blindness?
Sometimes. If retinal detachment is caught very early and blood pressure is lowered quickly, partial vision can occasionally be restored. Unfortunately, in many cases the blindness is permanent by the time it's noticed. This is why prompt blood pressure control and early detection through senior screening are so important for preserving sight.
How much does it cost to diagnose and treat cat hypertension?
A blood pressure measurement and exam typically run $50–150, with bloodwork to find an underlying cause adding $100–300 and an eye exam another $50–150. Amlodipine medication costs roughly $15–40 per month, plus periodic recheck visits. Catching and controlling it early is far cheaper than managing irreversible blindness or kidney failure.
Is high blood pressure in cats curable?
If the hypertension is secondary to a treatable condition like hyperthyroidism, resolving that disease can sometimes normalize blood pressure. More often, cats need lifelong medication such as amlodipine to keep pressure controlled, especially when chronic kidney disease is the driver. With consistent treatment and monitoring, the condition is very manageable even if not strictly "cured."
Which cats should be screened for high blood pressure?
Senior cats—generally those over 7 to 9 years—and any cat with chronic kidney disease, hyperthyroidism, diabetes, or heart disease should have blood pressure checked routinely. Because hypertension causes no early symptoms, these regular screenings during wellness visits are the main way the disease is caught before it damages the eyes or kidneys.
Still Not Sure if Your Cat Needs a Vet?
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