Hypotension is defined as abnormally low blood pressure. While Chronic Kidney Disease (CKD) is famously associated with high blood pressure (Hypertension), hypotension is a distinct and ominous sign usually seen in the end stages of the disease or during an acute "uremic crisis."
In the CKD patient, blood pressure is maintained by hydration and heart function. When a cat stops eating and drinking due to nausea, they become severely dehydrated. With less fluid volume in the veins, pressure drops. If the pressure falls below a critical threshold (typically a systolic pressure under 80-90 mmHg), the kidneys stop receiving enough blood to function at all. This lack of perfusion causes the kidneys to shut down completely (Acute Kidney Injury), accelerating the toxins in the blood. Clinical signs include cold extremities (paws and ears), pale gums, profound weakness, and a weak pulse. It is an immediate emergency requiring intravenous fluid therapy to "fill the tank" and restore blood flow to the vital organs before permanent damage occurs.
Disclaimer: This content is for educational purposes only and does not constitute veterinary medical advice. Always consult with your primary care veterinarian or a veterinary internal medicine specialist regarding your cat’s specific condition.