Read below about chills, including causes, treatment options and remedies. Or get a personalized analysis of your chills from our A.I. health assistant. At Buoy, we build tools that help you know what’s wrong right now and how to get the right care.

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Chills Symptoms

It's always nice to chill out...unless it is 20 degrees and the clothes you put on in the morning just aren't warm enough. The polar vortex has you shivering, chilled to the bone. If it is cold enough, you might get frostbite. Stay cold enough for long enough and hypothermia will set in. Hypothermia can cause confusion and exhaustion, until you can no longer make rational decisions (like getting yourself to a warmer environment).

Maybe it is the peak of summer. Despite the heat, you are sheltered in bed, wrapped in layers of thick blankets, cold, clammy and trembling with chills. You feel your temperature increasing. The continued trembling increases your temperature until you have a fever. Suddenly, you feel warm and flushed, your heart rate increases, and you find yourself breathing a little faster. Your lack of appetite, joint and muscles aches confirm your suspicion – you have some kind of virus or other infection.

Chills are a normal response to environmental or physical conditions. Chills are also a normal physical response to strong emotions - one that sends a chill down your spine.

Chills Causes Overview

Infection:

  • Whether viral or bacterial, any infection causing fever is also likely to cause symptoms of chills [1]. Chills, in the setting of infection, are part of your body's immune response. The shivering associated with chills requires a lot of energy as your muscles rapidly contract and relax. This energy creates heat, which in turn increases your body temperature until you have a fever. Fever helps to clear the infection.

Hypothyroidism:

  • Alters the way your body regulates temperature [2, 3, 4]. The sluggish metabolism of hypothyroidism can leave you chilled even when everyone around you is comfortably warm.

Hypothermia:

  • Hypothermia is important to recognize in its early stages, when it is most reversible [4]. As your body temperature falls below 35 degrees Celsius (95 degrees Fahrenheit) chill-related shivering helps the body warm up. However, once your body temperature dips below 32 degrees Celsius (90 degrees Fahrenheit), shivering stops. If you are shivering from the cold, and continuing to get colder and colder, but then the shivering stops, you are headed into danger.

Hypothermia is usually caused by being cold and/or wet, but can also be caused by:

  • Adrenal insufficiency
  • Neuromuscular diseases
  • Malnutrition
  • Hypoglycemia (low blood sugar)
  • Alcohol abuse
  • Some medications, including anti-anxiety drugs, anti-depressants, anti-psychotics, opiates and beta blockers (which are used to treat high blood pressure and some heart conditions) [4].

Post-operative:

  • Chills are common after surgery [5]. Most operating rooms are cold, most likely you have a body cavity open to room air, room temperature IV fluids are pumped into your veins, and you've been given general anesthesia which impairs your ability to regulate your body temperature. Under this combination of circumstances, shivering (chills) can occur.

Drug/alcohol withdraw:

  • We might joke about delirium tremens, but if it is you experiencing them, you will realize they are no laughing matter. Delirium tremens can occur during withdraw from alcohol, barbiturates or benzodiazepines [6]. In addition to chills, you might also experience hallucinations, an irregular heart rate and even seizures. This can lead to a medical emergency requiring immediate medical attention

Emotional chills:

  • Emotional chills can be the result of anything that triggers the softer side of your heart and soul - an experience that subjects you to fear, brings you joy, prompts you to wonder in profound ways, causes sadness or presents a shocking loss [7]. Such experiences can alter the firing of your brain's neurotransmitters, and can manifest in your body – sometimes as chills.

A.I. Health Assistant Causes for Chills

The list below shows results from the use of our A.I. Health Assistant by Buoy users who experienced chills. This list does not constitute medical advice.

  1. 1.Bacterial Pneumonia

    Bacterial pneumonia is the infection of the lungs with bacteria (as opposed to a fungus or a virus).

    1-3 weeks

    Rarity:
    Common
    Top Symptoms:
    fatigue, cough, headache, loss of appetite, shortness of breath
    Symptoms that always occur with bacterial pneumonia:
    cough
    Urgency:
    In-person visit
  2. 2.Kidney Infection (Pyelonephritis)

    Pyelonephritis is the medical term for a kidney infection. This can arise as a result of a bladder infection that travels upstream. A kidney infection is usually bacterial in nature, and can cause pain on the side of the stomach, high fever, nausea, and blood in the urine.

    Course of antibiotics for 7-14 days, but symptoms should begin to improve after 48 hours.

    Rarity:
    Uncommon
    Top Symptoms:
    abdominal pain (stomach ache), nausea, pelvis pain, back pain, vomiting
    Symptoms that never occur with kidney infection (pyelonephritis):
    mid back pain from an injury
    Urgency:
    Hospital emergency room
  3. 3.Viral Pneumonia

    Viral pneumonia is inflammation (irritation and swelling) of the lungs due to infection with a virus. Community-acquired pneumonia is the most common type, which is usually acquired in public areas such as at work, school, or grocery store.

    Symptoms begin to improve within a few days.

    Rarity:
    Uncommon
    Top Symptoms:
    fatigue, headache, cough, shortness of breath, loss of appetite
    Urgency:
    Primary care doctor
  4. 4.Sepsis

    Sepsis is a serious illness that is caused by the body's reaction to an infection and cause system-wide inflammation.

    Uncertain

    Rarity:
    Rare
    Top Symptoms:
    being severely ill, shortness of breath, fever, feeling confused and not making sense while talking, abnormally high heartrate
    Symptoms that always occur with sepsis:
    being severely ill
    Urgency:
    Emergency medical service
  5. 5.Influenza

    Influenza, or Flu, is an infection of the airway caused by the flu virus, which passes through the air and enters the body through the nose or mouth. The symptoms are similar to those of a cold, but the flu is usually more serious.

    Most recover within 1 week but cough and malaise can persist for 2 weeks.

    Rarity:
    Common
    Top Symptoms:
    fatigue, headache, loss of appetite, cough, muscle aches
    Symptoms that never occur with influenza:
    headache resulting from a head injury
    Urgency:
    Phone call or in-person visit

    Chills Checker

    Take a quiz to find out why you’re having chills.

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  6. 6.Viral (Rotavirus) Infection

    Rotavirus is a virus that causes an infection of the gut, known as gastroenteritis. Symptoms include diarrhea, vomiting and fever. When the diarrhea and/or vomiting is severe, dehydration can occur. Symptoms of dehydration include a dry mouth, dizziness, urinating less frequently and dark urine.

    Symptoms resolve on their own within a few days.

    Rarity:
    Ultra rare
    Top Symptoms:
    diarrhea, vomiting or nausea, nausea, fatigue, abdominal pain (stomach ache), headache
    Symptoms that always occur with viral (rotavirus) infection:
    diarrhea, vomiting or nausea
    Symptoms that never occur with viral (rotavirus) infection:
    constipation, tarry stool
    Urgency:
    Self-treatment
  7. 7.Viral (Norovirus) Infection

    Noroviruses are a group of related viruses that leads to nausea, vomiting, diarrhea, and cramps. These viruses cause gastroenteritis, an inflammation of the stomach and intestines. When the diarrhea and/or vomiting is severe, dehydration can occur. Symptoms of dehydration include a dry mouth, dizziness, urinating less frequently and dark urine.

    Usually resolves within 2-3 days.

    Rarity:
    Common
    Top Symptoms:
    diarrhea, vomiting or nausea, fatigue, nausea, abdominal pain (stomach ache), headache
    Symptoms that always occur with viral (norovirus) infection:
    diarrhea, vomiting or nausea
    Symptoms that never occur with viral (norovirus) infection:
    severe abdominal pain, throbbing headache, severe headache, tarry stool, vaginal bleeding, alertness level change
    Urgency:
    Self-treatment
  8. 8.Symptoms of Menopause

    Menopause is the point in life where your period stops. This happens when the ovaries stop making hormones that keep your cycle going. The transition into menopause is called peri-menopause and can include symptoms like hot flashes, shortening of menstrual cycle and mood fluctuations.

    Hot flashes typically peak approximately 1 year after the final period and last 4-10 years. Most women stop having hot flashes 4 years after they start, but 10% of women may have hot flashes up to 12 years after their last period.

    Rarity:
    Common
    Top Symptoms:
    fatigue, delay in or irregular periods, vaginal discharge, anxiety, trouble sleeping
    Symptoms that always occur with symptoms of menopause:
    delay in or irregular periods
    Urgency:
    Self-treatment
  9. 9.Tuberculosis

    Tuberculosis (TB) is a disease caused by bacteria called Mycobacterium tuberculosis, which most commonly affects the lungs, although it can also affect other organs in the body. The bacteria can lie dormant in the body for a long time (even years), until they start causing symptoms such as cough, fever, loss of appetite, and night sweats.

    >6 months treatment with antibiotics.

    Rarity:
    Rare
    Top Symptoms:
    fatigue, cough, shortness of breath, rib pain, dry cough
    Urgency:
    In-person visit
  10. 10.Mild Hypothermia

    Hypothermia is defined as a body core temperature lower than 95 degrees Fahrenheit or 35 degrees Celcius.

    With treatment, symptoms resolve within days.

    Rarity:
    Ultra rare
    Top Symptoms:
    fatigue, coldness, pale skin, turning blue or purple from coldness, shivering
    Urgency:
    Hospital emergency room

Chills Treatments and Relief

Seek medical care if you have chills and:

  • a fever that does not get better after taking acetaminophen or a non-steroidal anti-inflammatory medication such as ibuprofen [1].
  • you become confused or can't think straight.
  • frost bite. With progressive cold injury, your reddened skin becomes purplish or blue, then finally black. You might feel a prickly sensation at first, but then eventually lose feeling all together [9].

Our bodies have remarkable mechanisms to regulate our body temperature, but only within a narrow body temperature range [1]. We lose heat due to evaporation (such as sweating), and as our bodies lose heat to the surrounding, cooler air. We lose heat when we are in contact with cooler objects. Our bodies can only do so much before our muscles tire, our blood sugar levels drop and our adrenalin is exhausted.

Most of the time, chills can be reduced with warming [1, 4]. Limit the amount of time you spend outdoors on a cold day. Wet clothing should be removed and dry clothing put on as soon as possible. Layer blankets over yourself, and sip warm (non-alcoholic) drinks by the fire.

FAQs About Chills

Here are some frequently asked questions about chills.

Are the chills a sign of fever?

Chills very frequently accompany a fever as the body tries to warm itself to reach the set temperature necessary to help fight whatever virus or bacteria has invaded the body [1]. Chills, however, may happen in conjunction with a fever but may also be the product of different types of viruses, bacteria, and pathogens (e.g. malaria) [8, 9, 10]or different procedures like blood transfusion, or different drugs like anesthetic drugs [5].

Are the chills normal during pregnancy?

Isolated chills (chills that do not recur and are not accompanied by any other symptoms) are normal [1]. Repeated chills may be a sign of an infection and warrant a visit to your physician. By themselves and in small isolated bouts, chills are not worrisome. If you are worried, it is reasonable to contact your provider.

Are the chills a sign of a more serious condition?

Most commonly, chills are a sign of a cold surrounding environment. They may also happen during a fever from a bacterial or viral infection. Rarely, they can be associated with more dangerous or rare conditions. Malaria [11], for example, is known for causing chills, as well as transfusion of mismatched blood [11] and different types of cancers like mast cell leukemia [12] or mastocytosis [13]. Again, these are rare diseases and there is a high probability that chills are caused by a common viral illness like a cold or a flu.

When should you see a doctor for the chills?

If more than a week has passed and you are not getting better, you should see a physician [1]. If an infant has chills, he or she should be seen by a physician immediately. If you have chills accompanied by a fever >100.4 degrees Fahrenheit, you should see a doctor. Chills are common, but are abnormal, so if they are not occuring as part of a routine illness like a known cold or infection it is best to seek medical evaluation.

Questions Your Doctor May Ask About Chills

  • Q.Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
  • Q.Are you experiencing a headache?
  • Q.Have you experienced any nausea?
  • Q.Have you lost your appetite recently?

If you've answered yes to one or more of these questions, try our chills symptom checker to find out more.

Chills Quiz

Chills Symptom Checker Statistics

  • People who have experienced chills have also experienced:

    • 12% Fever
    • 6% Abdominal Pain (Stomach Ache)
    • 6% Headache
  • People who have experienced chills were most often matched with:

    • 40% Kidney Infection (Pyelonephritis)
    • 33% Bacterial Pneumonia
    • 26% Viral Pneumonia
  • Source: Aggregated and anonymized results from visits to the Buoy AI health assistant (check it out by clicking on “Take Quiz”).

A.I. Health Assistant

Take a quiz to find out why you’re having chills

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References

  1. Vorvick LJ. Chills. U.S. National Library of Medicine: MedlinePlus. Updated January 26, 2017. MedlinePlus Link.
  2. Hypothyroidism (Underactive). American Thyroid Association. American Thyroid Association Link.
  3. Hypothyroidism. Johns Hopkins Medicine. Johns Hopkins Medicine Link.
  4. Kraft S. Everything You Need to Know About Hypothermia. Medical News Today. Updated August 17, 2018. MNT Link.
  5. Eydi M, Golzari SEJ, Aghamohammadi D, Kolahdouzan K, Safari S, Ostadi Z. Postoperative Management of Shivering: A Comparison of Pethidine vs. Ketamine. Anesthesiology and Pain Medicine. 2014;4(2):e15499. NCBI Link.
  6. Sachdeva A, Choudhary M, Chandra M. Alcohol Withdrawal Syndrome: Benzodiazepines and Beyond. Journal of Clinical & Diagnostic Research. 2015;9(9):VE01-VE07. NCBI Link.
  7. Grewe O, Kopiez R, Altenmuller E. Chills as an Indicator of Individual Emotional Peaks. Annals of the New York Academy of Sciences. 2009;1169:351-354. NCBI Link.
  8. Pneumonia Symptoms, Causes, and Risk Factors. American Lung Association. Updated October 15, 2018. American Lung Association Link.
  9. Frostbite. U.S. National Library of Medicine: MedlinePlus. Updated April 17, 2018. MedlinePlus Link.
  10. Malaria. Centers for Disease Control and Prevention. Updated October 9, 2018. CDC Link.
  11. Gersten T. Transfusion Reaction - Hemolytic. U.S. National Library of Medicine: MedlinePlus. Updated February 1, 2017. MedlinePlus Link.
  12. Leukemia Symptoms. Cancer Treatment Centers of America. Updated October 9, 2015. Cancer Treatment Centers of America Link.
  13. Systemic Mastocytosis. Genetic and Rare Diseases Information Center. Updated September 6, 2016. GARD Link.