How to diagnose a fever at home
Most fevers require no treatment, though some home remedies can ease symptoms. Anyone with a very high fever should see a doctor for a full diagnosis.
Here, learn more about how to tell if a person has a fever.
Checking for a fever without a thermometer
Many people can tell when they are feverish, and some describe it as a feeling of warmth.
There is no completely accurate way to spot a fever without a thermometer. However, certain techniques can give a person a good idea of whether they have a fever.
These methods include:
Touching the forehead
A person likely cannot tell whether they have a fever by touching their own forehead.
Touching a person's forehead with the back of a hand is a common method of telling whether they have a fever. If the person has a fever, their forehead may feel very hot.
This can be highly inaccurate, but it may provide some general information.
However, a person with a fever who touches their own forehead may not feel anything unusual, so it is important to ask someone else for help.
A person may also be able to check for a fever by resting their cheek against the person's forehead.
Pinching the hand
Dehydration can be one sign of a fever. To check for dehydration, a person can pinch the skin on the back of their hand, then let the skin go and watch it carefully.
If they are well hydrated, their skin will fall back into place very quickly. If the skin moves slowly, the person may be dehydrated.
However, this method can be inaccurate because dehydration does not always indicate a fever.
Looking for flushing in the cheeks
Checking in a mirror for any signs of flushed cheeks can help a person tell whether they have a fever.
The cheeks may be reddish or purple, or they may simply have more color than usual if a person has a fever.
Checking urine color
Urine color may also help indicate whether someone has a fever.
Fevers dehydrate the body, which can prevent it from making as much urine as usual. This leads to more concentrated urine, which may be dark yellow or orange.
Looking for other symptoms
Other signs and symptoms of a fever can include:
- a headache
- soreness and aching
- weak muscles
- sore eyes
- general fatigue
- a loss of appetite
- difficulty concentrating
- swollen lymph nodes
Checking for a fever with a thermometer
Checking for a fever is straightforward when a person has a thermometer. There are a few different types of thermometer:
Different types of thermometers include oral, ear, and rectal thermometers.
Oral thermometers take the temperature in the mouth. Most modern oral thermometers are digital. They usually beep when they complete a reading, which makes them very easy to use.
Oral thermometers are easier for adults, as they require a person to close their mouth and keep the thermometer in place for about 20 seconds to get an accurate reading.
The thermometer should rest as close to the center of the mouth as possible. Once it has taken the reading, it will display the person's temperature.
Ear thermometers measure the temperature of the eardrum. They are more common in doctors' offices, but at-home versions are available.
Ear thermometers can give results within a few seconds. This makes them a good option when dealing with very young children, who can have a hard time sitting still.
However, ear thermometers can give less accurate readings than other types.
To use an ear thermometer, hold the device up to the ear, with the sensor pointing inward, down the ear canal toward the eardrum. Turn on the thermometer, and wait for it to signal that the reading is complete.
A rectal thermometer takes the temperature of the rectum. While it may not be the most easy or comfortable option, it does provide highly accurate readings.
As researchers note, rectal thermometers give more accurate readings than ear or oral thermometers.
To use a rectal thermometer, apply a lubricant to the tip and gently insert it into the rectum. A person can do this with an oral thermometer or purchase one designed for rectal use.
Rectal thermometers may be the best option when caring for infants. An accurate reading is vital when a baby may have a fever or otherwise need medical attention.
Fever in children
It is important to catch fevers in infants and children early, before their temperatures rise very high.
Beyond feeling very hot, an infant or young child with a fever may:
- have skin that is red or flushed
- be irritable
- be unusually tired
- have difficulty drinking or breastfeeding
A fever in a child is any temperature over 101.3°F (38.5°C). Older children may show many of the same symptoms as adults.
Most fevers result from infections, which trigger the body's natural defenses. The body's temperature rises, killing off harmful bacteria or viruses.
Types of infection that can cause a fever include:
- upper respiratory tract infections, such as a cold or flu
- lower respiratory tract infections
- skin infections
- urinary tract infections
- gastrointestinal infections
Other health issues that can lead to a fever include:
- heat stroke
- physical exertion
- reactions to certain medications
- chronic conditions, such as rheumatoid arthritis
- cancerous growths
Treatment for a fever usually involves addressing the underlying cause and controlling any symptoms.
Over-the-counter medicines can help relieve the symptoms of a fever.
Over-the-counter medicines are often the first-line treatment for a fever.
Nonsteroidal anti-inflammatory drugs can usually help reduce a fever and accompanying symptoms, such as pain.
Common examples of these drugs include:
Never give aspirin to a child, due to the risk of a life-threatening complication called Reye's syndrome.
Fluid intake is crucial when a person has a fever, because the process of raising the body's temperature uses a lot of water.
Drinking plenty of water throughout the day helps combat the effects of the fever and prevent dehydration.
It is also helpful to drink soup broth. The salts that it contains can help replenish the body's electrolytes when a person is sweating.
If a fever results from exertion or heat stroke, medications may not help. Instead, a person needs to cool down.
Sitting in a cool room may help, but avoid extreme temperatures. Do not cool off by taking a very cold bath or shower, for example. A cold bath or shower can cause a person to shiver, raising their body temperature even higher.
However, sponging the body with lukewarm or cool water may help, as the water will evaporate and cool the skin.
When to see a doctor
A fever often requires no medical treatment. It will usually go down in time, and the person can focus on relieving their other symptoms.
However, adults with very high fevers — above 104°F (40°C) — should see a doctor.
Children may need to see a doctor sooner. Infants younger than 3 months should receive medical attention if they have a rectal fever of over 100.4° F (38°C).
Also, anyone who has had a fever for more than 48 hours should see a doctor for a diagnosis and treatment.
A fever is the body's reaction to various issues, including infection, sunburn, and dehydration.
A thermometer is the most accurate tool, but other techniques can help a person tell whether they have a fever.
A fever usually resolves on its own. However, see a doctor if a fever is very high or does not go down after 48 hours.