Chills: Symptoms, Causes and Treatment

Chills are a common yet often misunderstood physical sensation that can signal a variety of underlying processes in the body. Whether you’ve experienced them as shivers running down your spine during a fever or as uncontrollable shaking when you catch a cold, chills are an important symptom that can indicate illness, infection, or even a body’s response to certain medications. This article provides a comprehensive look at chills—their symptoms, causes, and the best evidence-based approaches to treatment—so you can better understand this intriguing bodily response.

Symptoms of Chills

Chills are much more than just feeling cold. They can range from mild shivering to severe, uncontrollable tremors that may leave you feeling exhausted. Recognizing the spectrum of symptoms can help you identify when chills are just a temporary nuisance or when they might signal a more serious health issue.

Shivering and Muscle Tremors

The hallmark symptom of chills is shivering—those involuntary muscle contractions the body uses to generate heat. These tremors can be subtle or severe, sometimes described as "shaking chills" when the intensity increases. Shivering typically occurs as the body attempts to raise its core temperature in response to internal cues, most often during the onset of an infection or exposure to cold environments 1 4.

Sensation of Cold

Many people describe chills as a profound feeling of coldness that is not necessarily related to the surrounding temperature. This paradoxical sensation often precedes a rise in body temperature (fever) and can make you feel cold even when bundled up or in a warm room 1.

Fever and Chills

Chills commonly occur alongside fever. As the immune system responds to infection, it raises the body’s temperature set-point, triggering shivering to generate extra heat. This is why chills are a classic sign at the onset of many infections 1 4.

Malaise and Fatigue

Severe chills can be exhausting and may leave you feeling fatigued and generally unwell—what doctors refer to as malaise. This sense of discomfort can linger after the chills subside, especially when they are associated with illnesses like the common cold or influenza 3.

Causes of Chills

Chills do not occur in isolation—they are usually prompted by a range of physiological and environmental triggers. Understanding these causes can help you determine when chills are harmless and when they might require medical attention.

Infection and Immune Response

The most frequent cause of chills is infection. When bacteria or viruses invade the body—especially the bloodstream—the immune system responds by releasing chemicals that raise the hypothalamic set-point for body temperature. The chill phase occurs as your body works to align its actual temperature with this new, higher set-point, resulting in shivering and a sensation of cold 1. Notably, the presence of bacteria in the blood alone does not immediately trigger chills; there is often a lag period after the microbial invasion before chills set in 1.

Examples:

• Common cold: Chills often mark the onset of illness.
• Influenza: High fevers and chills are typical.
• Serious infections: Sepsis and meningitis may present with severe chills and fever.

Chills Induced by Medications

Certain medications can provoke chills as a side effect, especially when administered intravenously. For example, amphotericin B, used to treat fungal infections, is notorious for causing intense shaking chills in some patients. This is thought to be due to the body’s response to the medication itself rather than an infectious process 4.

Environmental Causes

Exposure to cold environments can also trigger chills. In these scenarios, the body attempts to generate more heat through shivering to maintain a stable core temperature. Unlike infection-induced chills, these are usually resolved by simply warming up 1.

Systemic Illnesses and Other Triggers

Chills can also be a sign of systemic illnesses unrelated to infection, such as autoimmune diseases or certain cancers. In these cases, the chills are often due to widespread inflammation or the release of pyrogens (fever-inducing substances) 1 3 6.

Treatment of Chills

Managing chills requires a careful approach that addresses both the sensation itself and the underlying cause. While the chills can be uncomfortable, effective treatment depends on whether they are due to infection, medication, or environmental factors.

Symptomatic Relief

The mainstay of chills treatment is symptomatic relief—making the patient comfortable while the body deals with the underlying cause.

Antipyretics

Medications like acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to lower fever and reduce discomfort associated with chills. NSAIDs have demonstrated particular benefit in reducing pain symptoms (headache, muscle aches) and malaise, though their ability to reduce chills is variable 3. They do not, however, significantly impact the total duration of illnesses like the common cold 3 6.

Warming Measures

For chills induced by cold environments, simple measures—such as wearing warm clothing, using blankets, or increasing ambient temperature—are usually sufficient 1.

Addressing Underlying Causes

Treating Infections

If chills are due to a bacterial or viral infection, treating the infection is crucial. For viral illnesses like the common cold, no cure exists, but supportive care and symptomatic treatments are recommended 6.

Zinc for the Common Cold

There is evidence that zinc lozenges can reduce the duration of symptoms associated with the common cold, potentially shortening the period during which chills and other symptoms are experienced 2 6. However, the optimal dosage and long-term safety require further research 2 6.

Meperidine for Severe Chills

For patients experiencing severe, drug-induced shaking chills (such as those receiving amphotericin B), the opioid meperidine has been shown to stop chills rapidly and effectively. In controlled studies, meperidine worked faster and more reliably than placebo, with minimal side effects 4. This approach is reserved for specific medical circumstances and should only be used under medical supervision.

When to Seek Medical Attention

While most chills are benign, certain situations warrant immediate medical attention:

• Chills with very high fever (>39°C/102°F)
• Chills accompanied by confusion, chest pain, or shortness of breath
• Chills in immunocompromised individuals
• Chills that persist without an obvious cause

Conclusion

Chills are a multifaceted symptom with a range of causes, from the common cold to serious infections and medication reactions. Understanding their symptoms, causes, and evidence-based treatment options empowers you to respond appropriately when chills strike.

Key Points:

• Chills often present as shivering, a feeling of cold, and may accompany fever and malaise 1 3 4.
• Most commonly, chills are triggered by the body’s immune response to infection, but they can also result from medications or environmental exposures 1 4.
• Symptomatic treatment—including antipyretics, NSAIDs, and warming measures—offers relief, while addressing the underlying cause remains essential 3 4 6.
• Zinc lozenges may help shorten the duration of cold-related chills, while meperidine is effective for severe, medication-induced chills 2 4.
• Seek prompt medical attention for chills associated with severe symptoms or in vulnerable populations.

By recognizing and appropriately managing chills, you can better navigate this common but important bodily signal and support your health through both mild and serious illnesses.