High Blood Pressure in Cats: Signs, Causes, and Treatment

Feline hypertension is persistently elevated blood pressure in a cat.  

Blood pressure fluctuates as the heart contracts and relaxes, and hypertension typically refers to abnormally high systolic blood pressure (the pressure in the arteries when the heart contracts and pumps blood).  

Persistent high blood pressure can damage organs, including the eyes, kidneys, heart, and brain. 

High blood pressure in cats can develop for several reasons. Most often, it’s secondary to an underlying health condition. 

The two most common causes of hypertension in cats are chronic kidney disease (CKD) and hyperthyroidism. 

• CKD: Damaged kidneys are less able to regulate the body’s fluid balance and blood pressure, which can cause blood pressure to rise. At least 60% of cats with hypertension also have evidence of CKD. 
• Hyperthyroidism: Excess thyroid hormone increases heart rate and the amount of blood the heart pumps, which can raise blood pressure. About 10–20% of cats diagnosed with hyperthyroidism also have hypertension.  

Other possible causes include diabetes mellitus, certain adrenal gland conditions, and some medications, such as corticosteroids and those that stimulate the nervous system. 

Less commonly, cats have primary (idiopathic) hypertension, meaning no underlying cause can be identified after other potential causes have been ruled out. 

Age is another important risk factor. High blood pressure is more common in older cats because conditions associated with hypertension, such as CKD and hyperthyroidism, become more common with age. 

Many cats with high blood pressure don’t show signs, and when symptoms are present, they are often subtle.  

In some cases, cats don’t appear sick until hypertension has caused damage to one or more organs.  

Possible signs include: 

• Sudden vision loss or blindness 
• Dilated pupils or pupils that respond poorly to light 
• Bumping into objects or difficulty navigating familiar spaces 
• Changes in behavior, such as confusion, restlessness, or disorientation 
• Weakness or difficulty walking 
• Seizures or other neurologic changes 
• Increased thirst or urination 
• Reduced appetite or weight loss 
• Vomiting 
• Nosebleeds 

Because cat high blood pressure may cause no obvious signs, routine blood pressure checks are particularly important for older cats and those with conditions such as CKD and hyperthyroidism. 

Persistent high blood pressure in cats can damage several organs, particularly those with small, delicate blood vessels. These are often called target organs and include: 

• Eyes: High blood pressure can damage blood vessels in the retina, potentially causing retinal bleeding, retinal detachment, and sudden or permanent vision loss. 
• Brain and nervous system: Hypertension can cause bleeding or swelling in the brain, potentially resulting in disorientation, weakness, difficulty walking, seizures, or other neurologic changes. 
• Kidneys: High blood pressure can damage the tiny blood vessels and filtering structures in the kidneys, contributing to or worsening CKD. This can create a harmful cycle in which kidney disease and hypertension make each other worse. 
• Heart: The heart may have to work harder to pump blood against increased pressure. Over time, this can cause thickening of the heart muscle and other cardiovascular changes.  

Because hypertension can quietly damage multiple organs, early detection and treatment are key to protecting a cat’s health and preventing potentially serious complications. 

High blood pressure in cats is diagnosed by measuring arterial blood pressure, usually with a cuff placed around the cat’s leg or the base of their tail. Systolic blood pressure—the pressure in the arteries when the heart contracts—is the measurement typically used to check for feline hypertension. 

A single high reading doesn’t necessarily mean a cat has hypertension. Veterinary visits can be stressful, and anxiety or excitement may temporarily increase blood pressure. For this reason, your veterinarian may allow your cat time to become comfortable, take several readings during the same visit, disregard unusually high or low values, and repeat measurements at a later visit if needed. 

Veterinarians commonly interpret systolic blood pressure using risk categories, such as: 

• Less than 140 mmHg: Normal; minimal risk of target-organ damage 
• 140–159 mmHg: Mild risk; monitoring may be recommended depending on the cat’s overall health 
• 160–179 mmHg: Moderate risk of target-organ damage; further evaluation and treatment may be warranted 
• 180 mmHg or higher: Severe risk of target-organ damage and generally warrants prompt veterinary attention 

These ranges are guidelines rather than a diagnosis. Your veterinarian will take repeated blood pressure measurements and assess the results along with your cat’s clinical signs; medical history; underlying diseases; and any damage to organs, such as the eyes, kidneys, heart, and brain.  

Treatment for hypertension in cats typically focuses on lowering blood pressure to reduce the risk of damage to important organs. The approach depends on how high the cat’s blood pressure is, whether they have organ damage, and whether an underlying condition is contributing to hypertension.  

Treatment may include: 

• Antihypertensive medication: Veterinarians commonly prescribe medications to lower blood pressure. The calcium channel blocker amlodipine is often used as a first-line treatment for cats. The dose may be adjusted based on follow-up blood pressure measurements and your cat’s response to treatment. 
• Treating underlying disease: When hypertension is associated with a condition such as CKD or hyperthyroidism, managing the condition is an important part of treatment. Controlling the underlying disease may help improve blood pressure, although many cats still require blood pressure medication. 
• Ongoing monitoring: Blood pressure should be checked regularly to assess whether treatment is working and whether medication adjustments are needed. Monitoring also helps veterinarians watch for signs of organ damage and ensure blood pressure doesn’t drop too low. 

Not all cases of high blood pressure in cats can be prevented, particularly when hypertension develops because of age-related factors or an underlying health condition. However, regular veterinary care can help identify and manage conditions such as CKD and hyperthyroidism before they lead to serious complications. 

Prevention and early detection focus on: 

• Routine veterinary exams 
• Regular blood pressure checks for senior cats and cats with conditions associated with hypertension 
• Early diagnosis and management of underlying diseases 
• Following prescribed treatments and monitoring recommendations 
• Watching for changes in vision, behavior, appetite, thirst, urination, and activity level 

Because feline hypertension can be present without obvious signs, regular blood pressure monitoring is the best way to detect the condition early and reduce the risk of permanent organ damage. 

A cat’s blood pressure is usually measured with a small cuff placed around a front or hind leg or the base of the cat’s tail. Multiple readings may be taken because stress can temporarily raise blood pressure. 

Yes. High blood pressure in older cats is common, particularly in cats with conditions such as CKD or hyperthyroidism. 

Yes. Severe hypertension can damage the blood vessels in the retina, causing retinal bleeding or detachment and potentially leading to sudden or permanent blindness. 

High blood pressure in cats can often be successfully managed with medication and treatment of underlying conditions, but lifelong treatment may be necessary. Regular blood pressure monitoring helps ensure treatment remains effective.