How Long Should a Fever Last?

You’re feeling under the weather. You may feel hot or cold. You may even have the shivers, a headache, or other aches and pains. Chances are, you have a fever. In some cases, a fever may be caused by a simple virus, like a cold or the flu. In others, it may be a sign of a more serious infection. In this article, we’ll discuss what constitutes a fever and how long a fever should last. We’ll review the stages of a fever and how to treat and relieve your fever symptoms at home.

What is a Fever?

A fever occurs when your body temperature increases above its usual range. While a fever isn’t a disease, it’s usually a sign that your immune system is fighting against harmful germs—like viruses or bacteria. Sometimes, a fever may be triggered by other factors, including medications, vaccinations, or inflammatory conditions. While a fever can be uncomfortable, it’s a sign that your immune system is kicking into high gear to help protect you against infection and speed up the healing process. The increase in temperature can create an environment less hospitable for pathogens while also helping to boost the production of white blood cells, which are essential for fighting off infections.

What is Considered a Fever?

“Normal” body temperature is typically around 98.6°F, but it can vary from person to person. It can also be higher during physical activity or in women during their menstrual cycle. There’s no one-size-fits-all definition for what counts as a fever, however, most healthcare providers consider a fever a temperature of 100.4°F or higher when measured orally.

Common Fever Causes

• Bacterial infections, like strep throat or pneumonia
• Viral infections, including the flu or COVID-19
• Gastrointestinal infections, like the stomach flu or salmonella
• Urinary tract infections (UTIs)
• Skin infections
• A reaction to certain medications, including antibiotics, anticonvulsants, and other drugs
• Certain vaccinations, like diphtheria, tetanus, hepatitis A or B, HPV, flu, and COVID-19
• Autoimmune disorders, including rheumatoid arthritis, lupus, and others
• Cancer

How Long Should a Fever Last?

A fever typically lasts no more than three to four days if it’s caused by an infection. If it lasts longer, if you have recurring fevers, or if you have a fever with difficulty breathing, you should contact your healthcare provider to determine the underlying cause of your fever.

A fever has three main fever stages: onset/invasion, steady, and decline.

1. Onset/Invasion Stage

This is when your body temperature starts to rise. It can happen either gradually or suddenly as your immune system responds to infection or other causes.

1. Steady Stage

In this phase, your fever reaches its peak temperature and remains elevated and stable for a period of time. Your body may maintain this high temperature to fight off infection.

1. Decline Stage

During this phase, your body temperature begins to return to normal. Like the onset stage, this can occur gradually or suddenly as your immune system successfully fights the infection or trigger.

There are also five main types of fever:

• Intermittent: Your body temperature fluctuates between normal and feverish levels, often returning to normal for periods of time.
• Remittent: Your temperature fluctuates more than two degrees, typically between morning and evening, but never fully returns to normal.
• Continuous: Your body temperature remains high, with variations of less than two degrees, staying consistently elevated without returning to normal.
• Hectic: This pattern involves wild and unpredictable temperature swings throughout the day.
• Relapsing: A fever that spikes again after a period of normal temperatures, often returning every few days or weeks.

While you have a fever, you might also experience physical changes, such as shivering or sweating, as your body works to regulate temperature.

How to Relieve Your Fever Symptoms at Home

There are several ways to find relief from your fever symptoms at home, including:

• Take over-the-counter (OTC) fever and pain relievers like acetaminophen or ibuprofen
• Stay hydrated by drinking plenty of fluids, such as water, diluted juices, broths, soups, ice pops, and sports drinks, to replenish electrolytes
• Rest
• Wear lightweight clothing
• Use a light blanket
• Avoid cold baths and showers, which can make shivering worse
• Sponge off with lukewarm water
• Eat healthy food and eat slowly
• Maintain a comfortable room temperature

When to Seek Medical Care for A Fever

Fevers are the body’s natural response to illness, but certain situations require medical attention to ensure your safety. Knowing when to seek help can make a significant difference in preventing complications. 

High Fever

Adults with a fever of 103°F (39.4°C) or higher lasting more than three days should seek medical attention, as it may indicate a serious condition. For children, a fever of 102°F or higher warrants contacting a healthcare provider, especially if accompanied by other symptoms.

Prolonged or Recurring Fever

If a fever lasts more than 48–72 hours without improvement, it could signal an underlying issue that needs evaluation. Similarly, fevers that come and go for over a week should be addressed by a medical professional to rule out chronic or systemic conditions.

Additional Symptoms with Fever

Certain symptoms accompanying a fever can indicate severe underlying conditions. Neurological signs such as a severe headache, rash, stiff neck, or confusion require immediate attention. 

Underlying Health Conditions

Individuals with pre-existing medical conditions face a higher risk of complications from a fever. For chronic illnesses, those who have recently completed treatments, or who are on immune-suppressant medications, should be especially vigilant and consult a healthcare provider promptly if a fever develops.

Recent Travel or Exposure

Fevers that arise after international travel may be linked to exposure to illnesses requiring specific treatments. Additionally, contact with someone who has tested positive for COVID-19 is a critical reason to consult a healthcare provider, as it may signal a potential infection.

Environmental Triggers

Fever following exposure to extreme heat or hot environments may indicate a heat-related illness, which requires immediate medical attention to prevent further complications.

Primary Care Fever Treatment at AllCare

At AllCare, our compassionate urgent care and primary care physicians provide comprehensive care for treating fever and their underlying illnesses. We also offer convenient flu testing, COVID-19 testing, sore throat treatment, and more. If you are experiencing any symptoms of a fever, schedule an appointment with AllCare today to determine the cause of your fever and get prompt, professional treatment.