Why Do I Have the Chills?
The honest verdict
This is usually not an allergy
Chills are rarely caused by an allergy. The most common cause is an infection — viral (cold, flu, COVID-19) or bacterial (urinary tract infection, pneumonia) — where chills signal that the body is raising its temperature to fight the pathogen. Cold exposure, intense exercise, hypoglycemia, and emotional stress can also trigger chills. True allergic reactions do not typically produce chills; however, in rare cases, a severe allergic reaction (anaphylaxis) can cause chills along with hives, swelling, and trouble breathing — this is a medical emergency.
This is a general research summary, not a diagnosis. It can't tell you what's causing your symptom — a clinician can.
Check this first
When chills is an emergency
Most of the time this can be handled calmly. But a few signs mean you shouldn't wait. Match what you're seeing to the right level of care below. Because this symptom can involve the nerves or the whole body, it's worth getting a clinician's eyes on it rather than self-treating.
If any emergency sign below is present, call 911 or go to the ER now.
- Emergency
Chills with stiff neck, severe headache, and sensitivity to light — go to the ER (possible meningitis).
Call 911 or go to the ER now
- Emergency
Chills with confusion, difficulty breathing, chest pain, or rapid heart rate — call 911 (possible sepsis or pneumonia).
Call 911 or go to the ER now
- Emergency
Chills with hives, swelling of the face/lips/tongue, or trouble breathing — call 911 (possible anaphylaxis).
Call 911 or go to the ER now
- Urgent
Chills with high fever (over 103°F / 39.4°C) in an adult, or any fever in an infant under 3 months — seek medical care.
Get seen today — urgent care or same-day visit
- See a doctor
Chills that persist for more than a few days, recur frequently, or are accompanied by unexplained weight loss or night sweats — see a clinician.
Book a routine visit with a clinician
When in doubt, err toward getting seen. These tiers are a general guide, not a substitute for a clinician's judgment about your specific situation.
Key facts
Chills are the body's way of generating heat through muscle contractions (shivering) to raise core temperature when fighting an infection.
Sepsis, a life-threatening response to infection, often presents with chills, fever, confusion, and rapid breathing — it requires immediate emergency care.
Anaphylaxis affects up to 2% of the population and can include chills, but the hallmark signs are hives, swelling, and trouble breathing — not chills alone.
What's causing it
The same symptom can come from very different places. Here are the usual suspects for Full body — the sensation of coldness and shivering, often accompanied by goosebumps and teeth chattering, tagged by mechanism and how common each one is — so you can see where an allergy actually fits.
Viral infection (cold, flu, COVID-19)
Chills are a classic sign that the body is fighting a viral infection. The hypothalamus raises the body's set point temperature, causing shivering and chills until the new temperature is reached. Other symptoms often include fever, sore throat, cough, and body aches.
Bacterial infection (pneumonia, UTI, strep throat)
Bacterial infections frequently cause chills, often with high fever. Pneumonia may bring chills with cough and chest pain; a UTI may cause chills with burning urination; strep throat causes chills with severe sore throat. These require medical treatment, often antibiotics.
Cold exposure or hypothermia
Being in a cold environment without adequate clothing or shelter causes the body to shiver to generate heat. Prolonged exposure can lead to hypothermia (dangerously low body temperature), which requires immediate warming and medical attention.
Intense exercise or physical exertion
After prolonged or intense exercise, especially in cold weather, the body can experience chills as core temperature drops rapidly. Dehydration and electrolyte imbalances can contribute. Rest, hydration, and warming usually resolve it.
Hypoglycemia (low blood sugar)
Low blood sugar can cause chills, shakiness, sweating, and confusion. This is most common in people with diabetes taking insulin or certain medications, but can also occur after prolonged fasting or heavy alcohol use. Eating a fast-acting carbohydrate usually resolves it.
Severe allergic reaction (anaphylaxis) — rare
In rare cases, a severe allergic reaction (anaphylaxis) can cause chills along with hives, swelling of the face or throat, trouble breathing, rapid heart rate, and dizziness. Anaphylaxis is a life-threatening emergency that requires immediate epinephrine and 911. Chills alone are not a sign of an allergic reaction.
Is this an allergy? Usually, no
It's a common assumption, so it's worth being clear about — and pointing you toward what's more likely going on.
Chills are usually not an allergy. True allergic reactions — including food allergies, drug allergies, and insect sting allergies — typically cause hives, itching, swelling, and trouble breathing, not chills. In rare cases, a severe allergic reaction (anaphylaxis) can cause chills along with other symptoms, but chills alone are not a sign of allergy. If you experience chills with hives, facial swelling, or difficulty breathing after eating a food, taking a medication, or getting stung, treat it as a potential anaphylactic emergency and call 911.
Because an allergy is unlikely to be the driver, the most useful next step is a clinician who can look at the actual cause — not an allergy test.
Relief you can try at home
If your symptom is mild and you have no red-flag signs, these gentle steps often help. They soothe — they don't replace figuring out the cause.
- 1
Take your temperature
Use a reliable thermometer to check if you have a fever. Chills often precede or accompany a rising fever. Knowing your temperature helps you decide whether home care or medical attention is needed.
- 2
Rest and stay warm
Cover yourself with a blanket or wear warm layers. Avoid overheating — if you start sweating, remove layers to prevent dehydration. Rest allows your immune system to fight the underlying cause.
- 3
Stay hydrated
Drink water, clear broth, or electrolyte drinks. Chills and fever increase fluid loss. Sip slowly if you feel nauseous. Dehydration can worsen chills and make it harder for the body to regulate temperature.
- 4
Use fever-reducing medication if appropriate
If you have a fever and are uncomfortable, acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) can help lower fever and reduce chills. Follow label directions and do not give aspirin to children or teenagers. These treat symptoms, not the underlying cause.
Stop any step that makes things worse. If the symptom isn't easing within a few days, check in with a clinician.
When to see a doctor
See a clinician if chills are accompanied by a high fever (over 103°F / 39.4°C), last more than a few days, or recur frequently. Seek emergency care for chills with stiff neck and severe headache (possible meningitis), confusion or difficulty breathing (possible sepsis), or hives and swelling (possible anaphylaxis). Chills with unexplained weight loss, night sweats, or persistent fatigue also warrant medical evaluation to rule out chronic infection or other conditions.
❓Frequently Asked Questions
No — typical allergies (hay fever, dust mite allergy, pet dander) do not cause chills. Allergic rhinitis causes sneezing, runny nose, and itchy eyes, but not chills. If you have chills without a fever, the cause is more likely cold exposure, intense exercise, low blood sugar, or anxiety. In very rare cases, a severe allergic reaction (anaphylaxis) can cause chills, but it will also produce hives, swelling, or breathing trouble.
Fever is an elevated body temperature (usually over 100.4°F / 38°C), while chills are the sensation of coldness with shivering. Chills often occur as the body's temperature is rising to reach a fever set point. You can have chills without a fever (from cold exposure or anxiety), and you can have a fever without chills. They are related but distinct symptoms.
Go to the ER if chills are accompanied by a stiff neck and severe headache (possible meningitis), confusion or difficulty breathing (possible sepsis), chest pain, a high fever that does not respond to medication, or signs of an allergic reaction (hives, swelling, trouble breathing). Chills in an infant under 3 months with any fever also require emergency care.
Yes — intense stress, anxiety, or panic attacks can trigger chills. The body's fight-or-flight response releases adrenaline, which can cause shivering, goosebumps, and a sensation of coldness. These chills typically resolve once the stressful situation passes or with calming techniques like deep breathing. Unlike infection-related chills, they are not accompanied by fever.
Chills without fever can result from cold exposure, intense exercise, low blood sugar, anxiety, or certain medications. Some infections, especially early in their course, may cause chills before a fever develops. If chills without fever persist or recur, see a clinician to rule out underlying conditions like anemia, thyroid issues, or chronic infection.
Medically reviewed by
Dr. Chet TharpeMD
Last reviewed July 2026
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Read moreThe best next step is a real clinician
This symptom is usually not driven by an allergy, so an allergy test won't give you the answer. A primary care doctor or the right specialist can examine what's actually going on and guide you from there.
Curex focuses on at-home allergy testing and immunotherapy, which isn't the right fit for this symptom — and never a substitute for medical care.
This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. It cannot tell you what is causing your chills or whether it is an allergy. If you have any emergency sign — trouble breathing, fast-spreading swelling, sudden weakness or confusion, or severe pain — call 911 or go to the nearest emergency room. For anything that is new, worsening, or persistent, see a licensed healthcare provider. Curex focuses on at-home allergy testing and immunotherapy, which is not the appropriate care for this symptom and never a substitute for a clinician.