Low blood pressure can cause chills, and the connection is straightforward: when blood pressure drops, your body diverts blood away from your skin and extremities to protect vital organs like the brain, heart, and kidneys. With less warm blood flowing near the surface, your skin turns cold and clammy, and you feel chilled. Blood pressure below 90/60 mmHg is generally considered low, and chills become more likely the further it falls.
Why Low Blood Pressure Makes You Feel Cold
Your body has a built-in triage system. When blood volume or blood pressure drops, the nervous system tightens blood vessels near the skin, muscles, and gut to keep blood flowing to the organs that matter most. This is why people with significant drops in blood pressure often have cold, pale, or clammy skin even in a warm room. The sensation of feeling cold or having chills is a direct result of that reduced blood flow to the surface.
This response kicks in early. Even a 10% reduction in circulating blood volume can trigger it, well before blood pressure readings look dramatically low on a monitor. Your body starts redistributing blood as a precaution, which means you may feel chilled before you notice other symptoms like dizziness or lightheadedness.
Common Causes Behind Both Symptoms
Dehydration and Fluid Loss
Dehydration is one of the most frequent reasons blood pressure and body temperature regulation go off track at the same time. When you lose fluid through sweating, vomiting, diarrhea, or simply not drinking enough, your total blood volume shrinks. The heart has less to pump, pressure falls, and the body clamps down on surface blood flow. Classic signs include a rapid heart rate, cold and clammy skin, dry mouth, decreased skin elasticity, and reduced urination. This can range from mild (feeling a bit chilly and lightheaded after skipping water on a hot day) to severe hypovolemic shock, which is a medical emergency.
Sepsis
Infections that spread to the bloodstream can cause a dangerous combination of chills and dropping blood pressure. In sepsis, the immune system releases inflammatory chemicals that cause blood vessels to widen dramatically, which tanks blood pressure. Early on, people often experience shaking chills (sometimes called rigors), weakness, and a high or sometimes low body temperature. As sepsis progresses, the heart beats rapidly, breathing speeds up, confusion sets in, and blood pressure continues to fall. This combination of chills with fever or confusion and low blood pressure is a red flag that needs immediate medical attention.
Severe Allergic Reactions
Anaphylaxis causes a sudden, sharp drop in both blood pressure and body temperature. Research from Duke Health has identified why: during a severe allergic reaction, sensory nerves involved in temperature regulation send the brain a false signal that the body is overheating. The brain responds by shutting down heat production in fat tissue, causing hypothermia. Simultaneously, blood pressure plummets. This is why people in anaphylactic shock often feel intensely cold, become pale, and may lose consciousness.
Orthostatic Hypotension
If you feel chilled or lightheaded when you stand up quickly, orthostatic hypotension may be involved. When you go from lying down to standing, blood pools in your legs. Normally, your heart rate and blood vessel tone adjust within seconds. When that system doesn’t work properly, often due to mild dehydration or nervous system dysfunction, blood pressure drops sharply on standing. You might feel cold, dizzy, or faint for a few moments before your body catches up.
Blood Pressure Medications
Certain medications that lower blood pressure can cause cold extremities as a side effect. Beta-blockers are the most common culprit. In studies of patients with high blood pressure, about 5% of those taking beta-blockers reported cold extremities, compared to lower rates in untreated patients or those on other medications. If you’ve noticed feeling colder since starting a blood pressure medication, that’s a recognized side effect worth mentioning to your prescriber.
Chills With Low Blood Pressure vs. Low Blood Sugar
Low blood sugar (hypoglycemia) can produce symptoms that overlap significantly with low blood pressure: shakiness, dizziness, weakness, a fast heartbeat, and pale skin. The key differences are that low blood sugar typically causes intense hunger, sweating, and difficulty concentrating, while low blood pressure more often causes cold or clammy skin, lightheadedness when standing, and a weak (rather than just fast) pulse. Both can cause confusion when severe. If you’re not sure which is happening, eating or drinking something with sugar is a reasonable first step, since it addresses blood sugar quickly and the fluid intake helps blood pressure too.
What to Do When It Happens
For mild episodes where you feel chilly and a bit lightheaded, the most effective immediate step is drinking water, and specifically cold water. Rapidly drinking about 16 ounces (two glasses) of cold water expands blood volume and triggers a nervous system response that can raise systolic blood pressure by more than 20 mmHg for about two hours. That’s a meaningful boost.
Beyond hydration, several practical strategies help:
- Increase salt and fluids. Aim for five to eight glasses of water per day. Salty broth or soup works well during an acute episode.
- Use muscle contractions. If you feel symptoms while standing, cross your legs and squeeze your thigh muscles, rise up on your toes repeatedly, or bend at the waist. These movements push blood back toward your core and can raise blood pressure within seconds.
- Elevate the head of your bed. Raising it about 4 inches reduces nighttime fluid loss and helps stabilize blood pressure the next morning.
- Wear an abdominal binder. Compression around the abdomen reduces blood pooling and helps maintain pressure when upright.
When Chills and Low Blood Pressure Signal an Emergency
Most episodes of mild low blood pressure with chills resolve with fluids and rest. But certain combinations of symptoms indicate shock, which requires emergency care. Watch for cold skin paired with rapid, shallow breathing and a weak but fast pulse. Loss of consciousness, confusion, or a bluish tint to the skin are also emergency signs. Chills with high fever, rapid heart rate, and falling blood pressure suggest possible sepsis. Any sudden episode following exposure to a known allergen, insect sting, or new medication could indicate anaphylaxis. In all of these situations, call emergency services immediately rather than trying to manage symptoms at home.