Chills & Shivering With and Without Fever Explained
It's always nice to chill out — that is, unless it's 20 degrees outside and you're shivering in your thin sweater. Or, maybe you find yourself shivering in the peak of summer. Despite the heat, you are sheltered in bed, wrapped in layers of thick blankets — cold, clammy and trembling with chills.
Common characteristics and accompanying symptoms of chills
If you're experiencing chills, it's also likely to experience:
- Feeling warm, hot, or flushed
- As if you have a fever
- Trembling: This may be frequent or infrequent. Continued trembling has a purpose. It increases your body's temperature until you have a fever.
- Faster heart rate
- Lack of appetite
- Join and muscle aches
Chills are also a normal response to environmental or physical conditions. Chills are also a normal physical response to strong emotions, such as those that send a chill down your spine.
What Causes Chills?
Whether viral or bacterial, any infection causing fever is also likely to cause symptoms of chills . 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 [2-4]. The sluggish metabolism of hypothyroidism can leave you chilled even when everyone around you is comfortably warm.
Hypothermia is important to recognize in its early stages, when it is most reversible . 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
- 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) 
Chills are common after surgery . 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.
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 . 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 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 . Such experiences can alter the firing of your brain's neurotransmitters, and can manifest in your body sometimes as chills.
10 Possible Chills Conditions
The list below shows results from the use of our quiz by Buoy users who experienced chills. This list does not constitute medical advice and may not accurately represent what you have.
Bacterial pneumonia is an infection of the lungs caused by one of several different bacteria, often Streptococcus pneumoniae. Pneumonia is often contracted in hospitals or nursing homes.
Symptoms include fatigue, fever, chills, painful and difficult breathing, and cough that brings up mucus. Elderly patients may have low body temperature and confusion.
Pneumonia can be a medical emergency for very young children or those over age 65, as well as anyone with a weakened immune system or a chronic heart or lung condition. Emergency room is only needed for severe cases or for those with immune deficiency.
Diagnosis is made through blood tests and chest x-ray.
With bacterial pneumonia, the treatment is antibiotics. Be sure to finish all the medication, even if you start to feel better. Hospitalization may be necessary for higher-risk cases.
Some types of bacterial pneumonia can be prevented through vaccination. Flu shots help, too, by preventing another illness from taking hold. Keep the immune system healthy through good diet and sleep habits, not smoking, and frequent handwashing.
Top Symptoms: fatigue, cough, headache, loss of appetite, shortness of breath
Symptoms that always occur with bacterial pneumonia: cough
Urgency: In-person visit
Kidney infection (pyelonephritis)
A kidney infection, or pyelonephritis, is actually a type of urinary tract infection (UTI) that begins in the urethra or bladder and spreads to the kidneys.
The infection is caused by bacteria that either travel into the urethra or spread from an infection elsewhere in the body.
Women, especially pregnant women, are most susceptible. Anyone who has had a urinary tract blockage, or uses a catheter, or has a weakened immune system is also at risk for a kidney infection.
Symptoms include fever; chills; back and abdominal pain; and frequent, painful urination. If there is also nausea and vomiting and discolored, foul-smelling urine, take the patient to the emergency room or call 9-1-1.
Left untreated, pyelonephritis can cause permanent damage to the kidneys. Bacteria can also enter the bloodstream and cause a life-threatening infection elsewhere in the body.
Diagnosis is made through urine test, blood test, and sometimes imaging such as ultrasound, CT scan, or x-ray.
Treatment includes antibiotics and sometimes hospitalization.
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
Viral pneumonia, also called "viral walking pneumonia," is an infection of the lung tissue with influenza ("flu") or other viruses.
These viruses spread through the air when an infected person coughs or sneezes.
Those with weakened immune systems are most susceptible, such as young children, the elderly, and anyone receiving chemotherapy or organ transplant medications.
Symptoms may be mild at first. Most common are cough showing mucus or blood; high fever with shaking chills; shortness of breath; headache; fatigue; and sharp chest pain on deep breathing or coughing.
Medical care is needed right away. If not treated, viral pneumonia can lead to respiratory and organ failure.
Diagnosis is made through chest x-ray. A blood draw or nasal swab may be done for further testing.
Antibiotics do not work against viruses and will not help viral pneumonia. Treatment involves antiviral drugs, corticosteroids, oxygen, pain/fever reducers such as ibuprofen, and fluids. IV (intravenous) fluids may be needed to prevent dehydration.
Prevention consists of flu shots as well as frequent and thorough handwashing.
Top Symptoms: fatigue, headache, cough, shortness of breath, loss of appetite
Urgency: Primary care doctor
Sepsis is a serious illness that is caused by the body's reaction to an infection and cause system-wide inflammation.
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
Influenza, or "flu," is a contagious respiratory illness caused by viruses. It is spread through the air by coughing, sneezing, or even talking.
Anyone can get the flu, but those who are very young, over 65, and/or have pre-existing medical conditions are most at risk for complications.
Symptoms include fever, chills, cough, sore throat, body aches, and extreme fatigue. The symptoms may appear very suddenly.
Flu can bring on secondary bacterial infections in the lungs or ears. Dehydration is a great concern because the patient rarely wants to eat or drink.
Diagnosis is usually made by symptoms. There are tests that use a swab taken from the nose or throat, but they are not always accurate or necessary.
Treatment consists mainly of good supportive care, which means providing the patient with rest, fluids, and pain-relieving medication such as ibuprofen. Do not give aspirin to children.
Antibiotics cannot help with the flu, since antibiotics only work against bacteria. There are anti-viral medications that a doctor may prescribe.
The best prevention is an annual flu shot.
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
Viral (rotavirus) infection
Rotavirus infection is a contagious gastrointestinal virus that most often affects babies, toddlers, and young children. It causes severe watery diarrhea, sometimes with vomiting and fever.
Adults may also be infected, though usually with milder symptoms.
Rotavirus spreads very quickly when any trace of stool from an infected child contaminates food or drink, or gets onto any surface. If another child consumes the food or drink, or touches the surface and then their mouth, the child will become infected.
Rotavirus in adults does not usually need a trip to the ER unless the degree of dehydration is severe but dehydration can set in quickly in children and is a medical emergency. A child can die if not treated immediately. Take the child to an emergency room or call 9-1-1.
Treatment consists of drinking fluids or IV fluids in severe cases and supportive care, usually in a hospital. Antibiotics will not help rotavirus because they only work against bacteria.
The best way prevention is frequent and thorough handwashing, as well as washing toys and surfaces when possible. There is now a vaccine that will either prevent rotavirus infection or greatly lessen the symptoms if the child still gets the virus.
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
Viral (norovirus) infection
If you ever heard of an entire cruise ship of people coming down with the same “stomach bug,” chances are that was norovirus. Fortunately, norovirus usually goes away on its own after a few days, but is pretty unpleasant and can spread extremely easily. The ...
Symptoms of menopause
Menopause is the name for the natural process by which the menstrual cycle (period) stops happening in a woman. Usually, the process is gradual (takes months or years) and occurs from the age of 45 to 55 years. Menopause is officially diagnosed once a woman stops having a period for 12 months continuously. A woman with menopause will notice a decrease in the number and regularity of her periods until they completely stop. In addition, she may notice a number of symptoms that occur as a result of decreased estrogen levels, such as hot flashes, changes in mood, sleep problems, vaginal dryness, changes in libido, and changes in sexual function. Certain medications exist that can decrease these symptoms.
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
Tuberculosis, or TB, is a lung infection caused by the bacteria Mycobacterium tuberculosis. In some cases, it can affect other organs such as the brain or kidneys.
The disease spreads when an infected person exhales, speaks, or coughs and someone else inhales the bacteria. Tuberculosis is not transmitted any other way. Some patients carry TB without ever showing symptoms, though the disease may become active if something happens to weaken the immune system.
Most susceptible are those with weakened immune systems; infected with HIV; living or working in homeless shelters, correctional facilities, or nursing homes; and children under age 5.
Symptoms include severe cough that may bring up sputum and/or blood; chest pain; weakness; weight loss; fever; chills, and night sweats.
Diagnosis is made through skin tests, blood tests, sputum tests, and chest x-ray.
Treatment involves a course of specialized antibiotics under close medical supervision, along with rest and supportive care.
There is a vaccine for tuberculosis, but it is not entirely effective and not routinely given in the United States.
Top Symptoms: fatigue, cough, shortness of breath, rib pain, dry cough
Urgency: In-person visit
Hypothermia is defined as a body core temperature lower than 95 degrees Fahrenheit or 35 degrees Celcius.
Rarity: Ultra rare
Top Symptoms: fatigue, coldness, pale skin, turning blue or purple from coldness, shivering
Urgency: Hospital emergency room
When to Seek Treatment for Chills With or Without Fever
Our bodies have remarkable mechanisms to regulate our body temperature, but only within a narrow body temperature range . 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.
When you should see a doctor or emergency care for chills
Seek medical care if you have chills and:
- Fever: Especially one that does not get better after taking acetaminophen (Tylenol) or a non-steroidal anti-inflammatory medication such as ibuprofen (Advil, Motrin) .
- 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 .
At-home treatment for chills
Most of the time, chills can be reduced with warming [1,4].
- Limit the amount of time you spend outdoors on a cold day
- Wear dry clothing: Wet clothing should be removed and dry clothing put on as soon as possible.
- Warm yourself comfortably: Layer blankets over yourself and sip warm (non-alcoholic) drinks by a fire or heater.
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 . 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 .
Are the chills normal during pregnancy?
Isolated chills (chills that do not recur and are not accompanied by any other symptoms) are normal . 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 , for example, is known for causing chills, as well as transfusion of mismatched blood  and different types of cancers like mast cell leukemia  or mastocytosis . 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 . 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
To diagnose this condition, your doctor would likely ask the following questions:
- Have you been feeling more tired than usual, lethargic or fatigued despite sleeping a normal amount?
- Are you experiencing a headache?
- Have you experienced any nausea?
- Have you lost your appetite recently?
The above questions are also covered by our A.I. Health Assistant.
If you've answered yes to one or more of these questions
Take a quiz to find out what might be causing your chills
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”).
Chills Symptom Checker
Take a quiz to find out what might be causing your chills
- Vorvick LJ. Chills. U.S. National Library of Medicine: MedlinePlus. Updated January 26, 2017. MedlinePlus Link.
- Hypothyroidism (Underactive). American Thyroid Association. American Thyroid Association Link.
- Hypothyroidism. Johns Hopkins Medicine. Johns Hopkins Medicine Link.
- Kraft S. Everything You Need to Know About Hypothermia. Medical News Today. Updated August 17, 2018. MNT Link.
- 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.
- Sachdeva A, Choudhary M, Chandra M. Alcohol Withdrawal Syndrome: Benzodiazepines and Beyond. Journal of Clinical & Diagnostic Research. 2015;9(9):VE01-VE07. NCBI Link.
- 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.
- Pneumonia Symptoms, Causes, and Risk Factors. American Lung Association. Updated October 15, 2018. American Lung Association Link.
- Frostbite. U.S. National Library of Medicine: MedlinePlus. Updated April 17, 2018. MedlinePlus Link.
- Malaria. Centers for Disease Control and Prevention. Updated October 9, 2018. CDC Link.
- Gersten T. Transfusion Reaction - Hemolytic. U.S. National Library of Medicine: MedlinePlus. Updated February 1, 2017. MedlinePlus Link.
- Leukemia Symptoms. Cancer Treatment Centers of America. Updated October 9, 2015. Cancer Treatment Centers of America Link.
- Systemic Mastocytosis. Genetic and Rare Diseases Information Center. Updated September 6, 2016. GARD Link.
Disclaimer: The article does not replace an evaluation by a physician. Information on this page is provided as an information resource only, and is not to be used or relied on for any diagnostic or treatment purposes.