The 99.8 Fever – What You Need to Know About Low Grade Fevers

The symptoms of illness are vast and various – from generalized weakness, to coughs and a runny nose. But even with a combination of these symptoms, many of us won’t assume sickness. It’s only when we develop a fever that acknowledging the presence of a viral or bacterial infection becomes undeniable.

But what happens if you develop a fever that isn’t quite as pronounced?

99.8 is a low grade fever.

Many will agree that a low grade fever is a difficult symptom to understand, simply because it doesn’t seem to warrant the same aggressive treatment that a full on fever requires. The usual question is whether to treat a low grade fever as is or to wait for a moderate fever to develop before trying anything.

So what’s the right course of treatment for something that doesn’t seem like such a cause for alarm? Find out everything you need to know about low grade fevers, what they mean, and what you can do about them with this detailed guide.

What is a Low Grade Fever?

There’s a bit of a gray area when it comes to assessing fevers. This comes from the fact that temperature can be taken from different parts of the body. Because of the slight variations in the readings you might collect among these different areas, what might be a fever in some sites might not be a fever in others.

To better explain this concept, I’ve put together a simple table to define the borders between fevers depending on where the temperature reading is taken:

Site Low Grade Fever Moderate Fever High Fever
Adult Child Adult Child Adult Child
Axillary 98.6-99.8 99.5-100.4 100.5-101.3 100.5-103.5 ≥101.2 ≥103.5
Temporal 99-100.4 99-100.4 100.4-101.3 100.5-103 ≥101.2 ≥103
Rectal 99-100.4 100-100.4 101.5-102.2 100.5-103 ≥102.2 ≥103
Oral 98.6-100.4 99.5-100.4 100.5-101.3 100.5-103.5 ≥101.2 ≥103.5
Ear 99-100.4 100-100.4 100.4-101.3 100.5-103 ≥101.2 ≥103.5

Keep in mind that when your child reaches the age of 36 months or three years, you should start using the adult fever readings as your basis for determining the presence of a fever. The values shown in the table for children’s fevers apply only to individuals less than three years of age.

Based on the chart above, a low grade fever is a temperature that’s between normal body temperature and a moderate fever. While it might not be as uncomfortable or as pronounced as a moderate or high fever, a low fever can be indicative of specific conditions and infections, giving you a signal as to what you should do about the subtle rise in body temperature.

What Typically Causes a Low Grade Fever?

To better understand how low grade fevers come about, it’s best to first understand what a fever is in general. Basically, a fever is an increase in body temperature, triggered by some sort of infection, illness, or disease. The rise in temperature helps kill off any foreign bodies in our system because certain types of bacteria and viruses can’t survive in warm environments.

In this light, we can assume that a low grade fever indicates the beginning of our system’s defense against potential threats. But what does it mean if a low grade fever never progresses into a moderate or high fever? More so, what does it mean when a low grade fever remains the same over an extended period of time?

Other Possible Causes of a Low Grade Fever

More often than not, a low grade fever indicates either a bacterial or viral infection. However, if your condition doesn’t resolve with OTCs or antibiotics, it’s possible that there’s something else causing the slight increase in temperature.

The second most likely cause for a persistent low grade fever in adults is a reaction to a medication. Some drugs are formulated to slightly increase a user’s body temperature as a side effect of its primary purpose. A common drug known to induce a fever is penicillin.

Strain and sprain have also been known to cause slight fevers. When a part of your body is overworked or injured, you may feel a slightly increased temperature over the affected area. This is your body’s attempt to repair the injury by encouraging more blood to flow through the involved region. Resolving the sprain or strain with rest, pain management medications, and modalities like hot and cold compress should resolve the fever as well.

While they’re not as common, there are a number of other, more serious causes for a prolonged low grade fever. These include, but are not limited to:

  • Arthritis
  • Vasculitis
  • Cancer
  • Acute hepatitis
  • Heat stroke
  • Immunization rejection
  • Stroke
  • Pulmonary embolism
  • Myocardial infarction

It’s important to keep in mind that a fever could indicate a variety of conditions – some easily resolved, and others more complicated and dangerous. With that, it’s ideal that you consult your trusted physician to get a solid diagnosis.

When Should You Worry About a Low Grade Fever?

Generally, a low grade fever shouldn’t be a cause for alarm especially if it’s not accompanied by any other symptoms. If this is the case for you, then simple steps like getting more rest, staying hydrated, and taking over-the-counter fever reducers should be more than enough to help resolve your situation. That said, you don’t need to wait for a low grade fever to develop into a moderate fever before you take action. In fact, doctors recommend that you act as soon as you detect the heightened temperature to help manage the symptoms earlier on.

However, if you’ve been experiencing a low grade fever for several days without resolve and it comes hand in hand with a variety of other symptoms, then it might be time to seek prompt medical care and consultation.

What symptoms should you keep an eye out for in combination with your low grade fever?

  • Chills
  • Generalized weakness
  • Vomiting
  • Bloody stool
  • Altered consciousness
  • Sore throat
  • Shortness of breath
  • Body pain
  • Diarrhea or constipation
  • Loss of appetite
  • Skin color changes
  • Rashes
  • Seizures

If your low grade fever comes in combination with one or a number of these symptoms, it’s strongly recommended that you seek professional medical advice as soon as possible. This is especially true if your fever doesn’t resolve with the use of OTC medications, and remains consistent over a period of 2-3 days.

Treating a Low Grade Fever

While a low grade fever might not be as uncomfortable as a moderate or high fever, it can cause reduced productivity and energy levels. Adding the fact that it could easily develop into a higher temperature later on, it’s ideal that you respond to a low fever before it gets out of hand. Fortunately, low fevers are fairly easy to treat especially if they’re caused by nothing more than a viral infection. In some cases, you might not even need to take medication as low fevers can be treated with simple changes in your lifestyle and level of activity.

Here are a few simple treatment methods you can use to address a low fever:

  • Avoid engaging in physically demanding activities.
  • Stay hydrated. Pumping your system with fluids during the wake of a fever can prevent a lot of complications associated with both viral and bacterial infections.
  • Take more vitamin C. This micronutrient has been known to help boost our immune system to combat common illnesses.
  • Try an OTC fever reducer. Medications like ibuprofen have been known to work wonders when it comes to reducing a temperature, and also provide the added benefit of pain management.
  • Eat healthy. Supply your body with the vitamins and minerals it needs to stay strong during an infection.
  • Avoid anything too sweet. Sugars can easily induce a sore throat when you have a fever.
  • Avoid exposing yourself to too much cold. Take quick, warm showers and make sure to dry yourself completely immediately after.

In Closing

A low fever might seem like a simple issue, but it does serve an important purpose when it comes to determining your current level of health and wellness. So when you start to detect an increase in your temperature, act fast! If your low grade fever persists despite treatment, then make sure to seek out the advice of a licensed medical professional to get a head start on proper treatment.


  1. Scott Morris says

    Hey Teresa,
    Did you ever get this fever issue resolved?

  2. I have had a low grade fever for months. Doctors have tested for so many things and everything is normal. I’m so severely depressed and weak

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