A fever with chills often indicates that the body is fighting an infection or responding to an underlying condition. In many cases, the fever is caused by a mild viral infection that goes away with rest and supportive care. However, the same symptoms can also occur with infections or other conditions that may not go away on their own and require timely medical attention. Knowing what may be causing the fever and chills is important for accurate medical evaluation and appropriate treatment. To help, in this blog, we'll explore the common causes of fever with chills, their associated symptoms, treatment, and when to seek medical care.

What Causes Shivers during Fever?

Fever occurs when the body's internal temperature rises above its usual range and often develops as part of the body's immune response to an infection. During this period, the body's temperature regulation centre may raise the internal temperature set point ; to reach this new set point, the body produces heat through rapid muscle contractions, which cause shivering. As a result, a patient may feel cold and experience chills even when their body’s temperature is elevated.

Common Causes of Fever With Chills

Fever with chills can develop due to several infections and medical conditions. The most common causes include:

1. Viral Infections

Viral infections are among the most common causes of fever with chills. Common examples include influenza, COVID-19 and other respiratory viral infections. Viral gastroenteritis and other viral illnesses can also cause fever.

Most uncomplicated viral infections improve with rest, adequate fluids and supportive care. However, persistent or worsening fever may require medical evaluation.

2. Bacterial Infections

Several bacterial infections can cause fever with chills. These may include pneumonia, urinary tract infections, kidney infections, bacterial gastroenteritis and bloodstream infections. The type of infection depends on the part of the body affected.

Some bacterial infections require antibiotic treatment. The choice of antibiotic depends on the suspected or confirmed infection and should be determined by a doctor.

3. Urinary Tract and Kidney Infections

Urinary tract infections can cause fever and chills, particularly when the infection spreads to the kidneys. Pyelonephritis, a bacterial infection of the kidneys, can cause more pronounced fever and chills and requires timely medical treatment.

4. Gastrointestinal Infections

Foodborne illnesses and other gastrointestinal infections can cause fever with chills. These infections may result from bacteria, viruses or parasites and can affect the digestive system.

5. Malaria and Other Mosquito-Borne Infections

Mosquito-borne infections are another possible cause of fever with chills, particularly in areas where these diseases are prevalent. Malaria, dengue and chikungunya can cause fever, although their patterns and severity can vary.

Malaria, in particular, may cause episodes of chills followed by fever and sweating.

6. Other Causes

Not every case of fever with chills results from an infection. Inflammatory conditions, heat-related illness, certain medicines and other medical conditions can also cause an elevated body temperature.

Identifying the underlying cause is important because treatment varies depending on whether the fever results from a viral infection, bacterial infection, mosquito-borne disease or another condition.

Symptoms That May Occur With Fever and Chills

The symptoms can vary depending on the underlying cause. Common symptoms include:

• Shivering or feeling unusually cold

• Sweating

• Headache

• Muscle and body aches

• Weakness or tiredness

• Reduced appetite

• Dehydration

• Cough or sore throat

• Nausea or vomiting

• Diarrhoea

• Pain while urinating

The combination of symptoms can help a doctor determine whether you need further tests or treatment.

Diagnosis of Fever With Chills

A doctor will usually begin the diagnosis by asking about the patient's symptoms, their duration and any recent exposure to infections. The doctor may also check the patient's temperature, blood pressure, heart rate, breathing and other vital signs. Based on the assessment, the doctor may recommend diagnostic tests such as:

• Blood tests: A complete blood count (CBC) and other blood tests can provide information about the body's response to an illness or infection.

• Blood cultures: These tests may be recommended when there is a suspicion of bacteria or other microorganisms in the bloodstream.

• Urine tests: These can help identify urinary tract infections and other urinary conditions that may cause fever.

• Chest X-ray: This may be recommended when symptoms suggest a lung infection, such as pneumonia.

• Targeted infection tests: Depending on the symptoms and suspected cause, tests may be recommended for conditions such as malaria or specific viral infections.

Note: Not every test may be necessary. The treating doctor will recommend investigations based on the suspected cause and the patient's symptoms.

Treatment for Fever With Chills

Treatment depends on the underlying cause. Mild fever can often be managed with supportive care while the body recovers.

Stay Hydrated

Drink plenty of fluids to replace the water lost through fever and sweating. Water, soups and other suitable fluids can help maintain hydration.

Get Adequate Rest

Rest gives your body time to recover. Avoid strenuous physical activity while you have a fever or feel weak.

Wear Comfortable Clothing

Avoid wrapping yourself in excessive layers even when you experience chills. Comfortable clothing and a suitable room temperature can help you remain comfortable while your body regulates its temperature.

Take Medicines Only as Advised

Paracetamol or ibuprofen may help reduce fever and discomfort in suitable patients. However, the choice and dose depend on factors such as age, medical history and other medicines you take.

Do not start antibiotics on your own. Antibiotics treat certain bacterial infections and do not work against viral infections.

Treat the Underlying Cause

If a doctor identifies an infection or another medical condition as the cause, treatment will focus on that condition. Depending on the diagnosis, this may include prescription medicines, fluids or other appropriate treatment.

When Should You See a Doctor for Fever With Chills?

You should consult a doctor if the fever:

• Does not improve or continues to worsen despite home care

• Keeps returning

• Remains high

• Occurs with persistent vomiting or diarrhoea

• Is accompanied by pain while urinating

• Occurs with severe weakness or dehydration

• Is accompanied by breathing difficulty or chest discomfort

• Occurs with a rash or severe headache

Adults with a temperature of around 39.4°C (103°F) or higher should seek medical advice, particularly if the fever is accompanied by other concerning symptoms.

Seek Emergency Medical Care for Severe Symptoms

Seek emergency medical care if fever with chills occurs with:

• Difficulty breathing

• Chest pain

• Confusion or unusual behaviour

• Severe headache or stiff neck

• Persistent vomiting

• Seizures

• Severe abdominal pain

• A concerning or non-fading rash

• Significant dehydration

These symptoms can indicate a potentially serious condition and require prompt medical assessment 

Fever With Chills in Children and Infants

Parents should pay particular attention to fever in young children. Infants younger than three months with a temperature of 100.4°F (38°C) or higher require prompt medical assessment, as fever at this age can indicate a serious infection.

For older children, medical attention may be necessary if the fever persists, the child appears unusually sleepy or unwell, develops breathing difficulties, experiences repeated vomiting or shows other concerning symptoms.

Preventing Infections That Can Cause Fever and Chills

Not all causes of fever with chills are preventable, but several everyday measures can reduce the risk of common infections:

• Practise good hand hygiene: Wash hands regularly with soap and water, particularly before eating and after using the toilet.

• Follow food and water safety: Consume properly cooked food and safe drinking water to reduce the risk of gastrointestinal infections.

• Stay up to date with vaccinations: Recommended vaccines can help prevent infections that commonly cause fever.

• Prevent mosquito bites: Use insect repellent, wear appropriate clothing and use mosquito nets in areas where malaria and other mosquito-borne infections occur.

• Take travel precautions: Follow appropriate health advice when travelling to areas where certain infections are more common.

Get the Right Medical Care for Fever With Chills

Fever with chills can have many causes, so the right approach starts with identifying the underlying condition. At Ujala Cygnus Hospitals, our internal medicine specialists evaluate each patient based on their individual symptoms and medical history. Our specialists recommend appropriate diagnostic tests, such as blood tests, a chest X-ray and other investigations, to identify the cause of fever and determine the right course of treatment. For severe or rapidly worsening symptoms, we have emergency medical care to provide prompt assessment and treatment. To book a consultation with an Internal Medicine specialist at Ujala Cygnus Hospitals, call 9146691466.