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Fever for 14 days: Characteristics, Types, and When It’s Serious

Characteristics, Types, and When It’s Serious

A fever is a common side effect of illness like the flu. It happens when there is a temporary rise in body temperature. A fever is usually a sign that your immune system is busy fighting an infection or other illness.

In babies and toddlers even a slight fever may be a sign of a serious illness. In adults a fever is not usually serious or life-threatening.

However, sometimes a fever in adults can be a warning signal that something is not right. A high or persistent fever might be a sign of a serious health condition.

A fever is normally a short-term rise in temperature that helps your body get rid of illness. A fever begins when your immune system makes more white blood cells to fight an infection. The increase in white blood cells triggers your brain to heat your body up.

This causes a fever. In response, your body tries to cool itself off by tightening up on blood flow to your skin and contracting muscles. This makes you shiver and may cause muscle aches.

Your normal body temperature ranges from 97°F to 99°F (36.1°C to 37.2°C). You may have a fever if your temperature rises above this.

Adults typically have a fever if their body temperature increases to 100.4°F (38°C). This is called a low grade fever. A high grade fever happens when your body temperature is 103°F (39.4°C) or above.

Most fevers usually go away by themselves after 1 to 3 days. A persistent or recurrent fever may last or keep coming back for up to 14 days.

A fever that lasts longer than normal may be serious even if it is only a slight fever. This is because a recurrent fever might be a sign of a more serious infection or health condition.

Common fever symptoms in adults include:

  • sweating
  • chills (shivering)
  • headaches
  • muscle pain
  • loss of appetite
  • fatigue
  • weakness

Call your doctor immediately if you have a high grade fever — when your temperature is 103°F (39. 4°C) or higher. Get medical help if you have any kind of fever for more than three days. Let your doctor know if your symptoms get worse or if you have any new symptoms.

Serious symptoms

A fever may be a sign of serious illness if you have:

  • a severe headache
  • dizziness
  • sensitivity to bright light
  • stiff neck or neck pain
  • skin rash
  • difficulty breathing
  • frequent vomiting
  • dehydration
  • stomach pain
  • muscle cramps
  • confusion
  • seizures

Other signs that a fever may be serious are:

  • pain when urinating
  • not urinating enough
  • passing dark urine
  • passing urine that smells bad

If you have serious fever symptoms, let your doctor know if you have recently traveled to a different country or attended an event that had lot of people. This may help your doctor find out the cause.

Common causes of a fever in adults are:

  • viral infection (like the flu or a cold)
  • bacterial infection
  • fungal infection
  • food poisoning
  • heat exhaustion
  • serious sunburn
  • inflammation (from conditions like rheumatoid arthritis)
  • a tumor
  • blood clots

Some adults may have a higher risk of getting a fever. If you have a chronic health condition or have been treated for a severe illness, you may be more likely to get a serious fever.

Let your doctor know about any fever symptoms if you have:

  • asthma
  • rheumatoid arthritis
  • diabetes
  • Crohn’s disease
  • heart disease
  • sickle cell disease
  • liver disease
  • kidney disease
  • chronic lung disease
  • cystic fibrosis
  • cerebral palsy
  • stroke
  • multiple sclerosis
  • muscular dystrophy
  • HIV or AIDS

Some medications and treatments can also lead to a serious fever, these include:

  • antibiotics
  • blood pressure drugs
  • seizure medications
  • DTaP vaccine
  • pneumococcal vaccine
  • steroids
  • chemotherapy
  • radiation treatment
  • methotrexate
  • azathioprine
  • cyclophosphamide
  • post-transplant medications

A fever is not normally harmful on its own. Most fevers go away within a few hours to days as your body defeats an infection.

Help yourself feel better with these at-home flu remedies:

  • stay hydrated by drinking plenty of fluids, such as:
    • water
    • juice
    • soup
    • broth
  • eat light foods that are easy on the stomach
  • rest
  • use a cool compress, like a damp towel
  • take a warm sponge bath
  • dress in light, comfortable clothing
  • turn down the temperature in your room

Over-the-counter medications can help ease your fever and symptoms, like headaches and muscle pain:

  • ibuprofen (Advil, Motrin)
  • acetaminophen (Tylenol)
  • naproxen (Aleve, Naprosyn)

You may need treatment from your doctor for more serious causes of a fever. The treatment depends on the cause. Your doctor may prescribe medications to treat serious infections:

  • antibiotics
  • antivirals
  • antifungals

A fever may be a sign of serious illness. A high fever can also cause serious side effects.

Emergency Symptoms

Get emergency medical attention by going to the ER or calling an ambulance if you have any of these symptoms:

  • seizure or convulsions
  • fainting or loss of consciousness
  • confusion
  • hallucinations
  • severe headache pain
  • stiff or painful neck
  • difficulty breathing
  • hives or a rash
  • swelling in any part of the body

A fever in adults is usually not harmful on its own. It is a sign that your body is dealing with an infection or other illness. In some cases a high or long-lasting fever can be a sign of a serious illness. You may need urgent medical treatment.

Do not ignore a fever. Get plenty of rest and fluids to help your body heal. See your doctor if you have a fever that lasts longer than 3 days or if you have other severe symptoms.

If you have a chronic condition or have been treated for a serious illness, let your doctor know if you have any kind of fever.

Persistent Low-Grade Fever in Kids and Adults: Causes and Treatme

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Long lasting low-grade fevers can occur with viral or bacterial infections, stress, or certain medications. Other health conditions like thyroid issues or autoimmune diseases can also cause this symptom.

What is a low-grade fever?

A fever is when a person’s body temperature is higher than normal. For most people, normal is roughly 98.6° Fahrenheit (37° Celsius).

“Low-grade” means that the temperature is slightly elevated — between 98.7°F and 100.4°F (37.05°C and 38.0°C) — and lasts for more than 24 hours. Persistent (chronic) fevers are typically defined as fevers lasting more than 10 to 14 days.

A fever can mean a lot of different things, but most low-grade and mild fevers are nothing to worry about. Most often, an increase in body temperature is a normal response to an infection, like a cold or the flu. But there are many other less common causes of a persistent low-grade fever that only a doctor can diagnose.

A fever alone may not be a reason to call a doctor. Yet, there are some situations where you should get medical advice, especially if a fever lasts more than a few days. The presence of a fever can mean different things for adults, infants, and children.


For an adult, a fever isn’t usually a cause for concern unless it goes above 103°F (39.4°C). You should see a doctor if you have a fever higher than this.

If your fever is lower than 103°F, but lasts for more than three days, you should also visit a doctor.

You should seek immediate medical attention if any of these signs or symptoms accompanies a fever:

  • strange rash that rapidly worsens
  • confusion
  • persistent vomiting
  • seizures
  • pain when urinating
  • stiff neck
  • severe headache
  • throat swelling
  • muscle weakness
  • difficulty breathing
  • hallucinations


For infants under 3 months old, even a slightly higher than normal temperature can mean a serious infection.

Call your pediatrician for a low-grade fever if your baby seems unusually irritable, lethargic, or uncomfortable or has diarrhea, a cold, or a cough. In the absence of other symptoms, you should also see a doctor if a fever lasts continuously for more than three days.


If your child is still making eye contact with you, drinking fluids, and playing, then a low-grade fever isn’t likely a cause for alarm. But you should still visit a doctor if a low-grade fever lasts for more than three days.

Also call your child’s pediatrician if your child:

  • is irritable or appears very uncomfortable
  • has poor eye contact with you
  • vomits repeatedly
  • has severe diarrhea
  • has a fever after being in a hot car

Viral infections, like the common cold, are the most common cause of a persistent low-grade fever, but there are other less common causes to consider.

Respiratory infections

Your body naturally raises its body temperature to help kill the bacteria or virus causing an infection. Colds or the flu are caused by viruses. Colds in particular can cause a low-grade fever that lasts more than a few days.

Other symptoms of a cold include:

  • stuffy or runny nose
  • sore throat
  • sneezing
  • cough
  • fatigue
  • lack of appetite

Viral pneumonia and bronchitis are two other types of respiratory infections that can also cause a low-grade fever. Along with a fever, chills, and a sore throat, pneumonia and bronchitis come with a cough that persists for weeks.

In children, it’s common to experience “back-to-back” viral infections. This can make it seem like the fever is lasting longer than it should be.

Treatment for viral infections involves rest and fluids until your body takes care of the infection. You can take acetaminophen for reducing a fever if your symptoms are really bothersome. Fevers are important in helping your body fight off certain infections, so sometimes it’s best to wait it out.

If the infection is more serious, your doctor may prescribe antibiotics, antiviral drugs, or other medications to help treat the infection.

Urinary tract infections (UTIs)

Persistent fever can signal a hidden urinary tract infection in both children and adults. A UTI is caused by a bacterial infection. Other symptoms include pain and burning while urinating, frequent urination, and bloody or dark urine.

A doctor can examine a sample of urine under a microscope to diagnose a UTI. Treatment involves a course of antibiotics.


A low-grade fever can occur about 7 to 10 days after starting a new medication. This is sometimes called drug fever.

Drugs associated with a low-grade fever include:

  • beta-lactam antibiotics, such as cephalosporins and penicillins
  • quinidine
  • procainamide
  • methyldopa
  • phenytoin
  • carbamazepine

If your fever is related to a medication, your doctor may adjust your dosage or recommend a different drug. The fever should disappear once the medication is stopped.

Teething (infants)

Teething usually occurs between 4 and 7 months of age. Teething can occasionally cause mild irritability, crying, and a low-grade fever. If the fever is higher than 101°F, it’s not likely caused by teething and you should bring your infant to see a doctor.


A persistent fever can be caused by chronic, emotional stress. This is called a psychogenic fever. Psychogenic fevers are most common in young women and people with conditions often exacerbated by stress, such as chronic fatigue syndrome and fibromyalgia.

Fever-reducing drugs like acetaminophen don’t actually work against fevers caused by stress. Instead, anti-anxiety drugs are the therapy used to treat a psychogenic fever.


Tuberculosis (TB) is a highly infectious disease caused by a bacterium called Mycobacterium tuberculosis. Though TB is more common in developing countries, thousands of cases are reported in the United States each year.

The bacteria can remain inactive in your body for years and cause no symptoms. When your immune system is weakened, however, TB can become active.

Symptoms of active TB include:

  • coughing up blood or sputum
  • pain with coughing
  • unexplained fatigue
  • fever
  • night sweats

TB can cause a persistent, low-grade fever, especially at night, which can result in night sweats.

A doctor can use a test called the purified protein derivative (PPD) skin test to determine if you’re infected with the TB bacteria. People diagnosed with active TB disease have to take several medications for six to nine months in order to cure the infection.

Autoimmune diseases

Body temperature has been found to be elevated in some people with chronic autoimmune disease, such as multiple sclerosis and rheumatoid arthritis.

In one study, researchers learned that participants with a form of MS called relapsing MS who complained of fatigue also had a low-grade fever.

A low-grade fever is also a common symptom of RA. It’s thought to be caused by inflammation of the joints.

Diagnosing RA and MS can take time and may require multiple lab tests and diagnostic tools. If you’ve already been diagnosed with RA or MS, your doctor will want to first rule out another viral or bacterial infection as the potential cause of your fever.

In case of RA- or MS-related fever, a doctor will likely recommend that you drink plenty of fluids, remove extra layers of clothing, and take a nonsteroidal anti-inflammatory drugs (NSAIDs) or acetaminophen until the fever passes.

Thyroid issues

Subacute thyroiditis is an inflammation of the thyroid gland. It can cause a low-grade fever in some cases. Thyroiditis may be caused by infection, radiation, trauma, autoimmune conditions, or medications.

Other symptoms include:

  • muscle pain
  • fatigue
  • tenderness near the thyroid gland
  • neck pain that often radiates up to the ear

A doctor can diagnose thyroiditis with an examination of the neck and a blood test that measures thyroid hormone levels.


Certain cancers — lymphomas and leukemias in particular — can cause a persistent and unexplained low-grade fever. Keep in mind that a cancer diagnosis is rare and a fever is a nonspecific symptom of cancer. Having a persistent fever doesn’t usually mean you have cancer, but it can alert your doctor to run certain tests.

Other common symptoms of leukemia or lymphoma include:

  • chronic fatigue
  • bone and joint pain
  • enlarged lymph nodes
  • headaches
  • unexplained weight loss
  • night sweats
  • weakness
  • breathlessness
  • loss of appetite

Depending on the type and stage of the cancer, a doctor may recommend a combination of chemotherapy, radiation, surgery, or other treatments.

Fevers will usually go away on their own. Over-the-counter (OTC) medications can help to lower a fever, but sometimes it’s better to ride out a low fever with fluids and rest.

If you decide to take an OTC medication, you can choose between acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, aspirin, and naproxen.

For infants younger than 3 months, call your doctor first before giving them any medication.

For children, acetaminophen and ibuprofen are generally safe for reducing fever. Don’t give aspirin to children under 12 years old who are recovering from flu-like symptoms because it can cause a serious disorder called Reye’s syndrome.

If your child is younger than 12 years of age, talk to your doctor before giving them naproxen.

For teenagers and adults, acetaminophen, ibuprofen, naproxen, and aspirin are generally safe to use according to the instructions on the label.

Shop for acetaminophen and NSAIDs to help lower a fever.

Most low-grade and mild fevers are nothing to worry about.

However, you should call your doctor if you’ve had a fever for more than three days straight, or your fever is accompanied by more troublesome symptoms such as vomiting, chest pain, rash, throat swelling, or a stiff neck.

It’s hard to know when you should call a doctor for a baby or young child. In general, seek medical care if your baby is less than three months old and has any fever at all. If your baby is older than that, you don’t have to see a doctor unless the fever runs above 102°F (38.9°C) or lasts continuously for more than three days.

Continue to monitor your child’s temperature throughout the day. Rectal temperatures are usually the most accurate. Call your pediatrician’s office if you’re not sure what to do.

Dengue fever: symptoms, pathogen, transmission routes

Dengue fever is an infectious disease transmitted by insects. Pathology has a clear geographical reference and more often occurs in the countries of Southeast Asia, regions with a subtropical climate in Australia and South America. Due to the intensive development of tourism in these regions, cases of the disease are also noted in other states, but they are isolated. Every year, hundreds of thousands of inhabitants of the planet are diagnosed with Dengue fever, some of whom are unable to receive timely medical care and are forced to put up with serious complications of the infection.

Causes of Dengue Fever

The causative agent of the disease is Dengue arbovirus, which can be found in the body of mosquitoes and arthropods. There are several of its serotypes, each of which gives approximately the same picture of the disease in the human body. The pathogen is resistant to climatic factors, however, it quickly dies under the influence of UV radiation and with a sharp increase in ambient temperature.

The mechanism of transmission of the disease “Dengue fever” is associated with mosquitoes of the genus Aedes, which feed on the blood of humans and animals. When bitten by an infected subject, the pathogen enters the mosquito’s blood, where it multiplies rapidly without harm to the “host” organism. The incubation period can be up to 14 days, after which the insect and its bites become contagious. One contact of a dengue fever carrier with a healthy body is enough for the virus to enter his blood, and the intensive development of the disease begins.

In the human body, the incubation period of the virus lasts about 7-15 days, and the acute stage – from 7 to 12 days. The course of the disease is undulating and consists of two peaks of body temperature increase, between which there is a weakening of symptoms. However, this is not a reason to stop the treatment, otherwise the risk of relapse and complications increases significantly.

Symptoms of disease

After a mosquito bite, the virus penetrates into the cells of the lymph nodes and blood vessels, where its intensive replication begins. As the volume of pathogenic particles increases, they spread throughout the body and penetrate into the internal organs, partially blocking their functioning. There is an intoxication syndrome, the first sign of which is a feverish state.

Also among the symptoms of dengue fever:

  • headache;
  • copious respiratory secretions;
  • aching muscles and joints;
  • vomiting and nausea, other signs of digestive upset;
  • diarrhea;
  • drop in blood pressure.

Forms of the disease

The symptomatic picture allows us to classify the disease as follows:

The classic form of dengue fever. It is most often observed in the primary lesion. Characteristic symptoms are a significant increase in body temperature, which after 3 days is replaced by the normalization of the patient’s condition, after which the fever repeats again. Also, the disease is indicated by signs of intoxication, muscle pain, discomfort in the spine, swelling of the face, neurological disorders in the form of dizziness and insomnia. The rash on the body that occurred at the initial stage of the disease disappears after 3-7 days. The rash may resemble scarlet fever, appear as small hemorrhages, or look like blisters.

hemorrhagic form. It is more often observed in persons secondarily infected with the causative agent of Dengue fever. The incubation period can last up to 10 days, after which symptoms appear in the form of intoxication, lethargy and characteristic rashes. The latter may appear from a few points to an extensive spot, which often has complications in the form of nosebleeds and internal hemorrhages. Blood particles are observed in the patient’s stool and urine.

Dengue fever in children. In a child’s body, the pathogen makes itself felt with blurred symptoms, which complicates the diagnosis and does not allow timely treatment. More often, patients have such symptoms of dengue fever as intoxication syndrome, fever and rash, dry cough and difficult breathing. The duration of the disease is about 7 days.

Probability of complications

A patient’s refusal to seek medical attention for dengue fever can cause:

  • swelling and damage to the brain;
  • nerve inflammation;
  • otitis;
  • thrombophlebitis;
  • signs of toxic shock;
  • preterm birth or intrauterine fetal death for pregnant women.

Diagnostic methods

The doctor makes a preliminary diagnosis already at the stage of the initial examination and history taking. Unmistakable signs of fever are skin rashes, swollen lymph nodes, pain in the joints and muscles, as well as the wave-like development of a feverish state. If the patient has recently been in countries that are “dangerous” in terms of infection, he is immediately sent for laboratory tests:

Accurately establish the fact of infection allows differentiated diagnosis. Its goal is to exclude malaria, influenza, measles and rubella, which at the initial stage of the disease have similar symptoms.

The so-called flagellar test allows you to establish the hemorrhagic form of Dengue fever. A tourniquet is applied to the upper limb of the patient, after removing which, five minutes later, new areas of rashes can be seen on the skin.


A mandatory requirement for a patient in the treatment of Dengue fever is immediate hospitalization. Treatment is carried out under the strict supervision of a doctor and includes the following drugs:

  • Painkillers and anti-inflammatory drugs.
  • Sleeping and sedative formulations.
  • Glucocorticosteroids to eliminate the symptoms of intoxication.
  • Antibiotics that destroy pathogens.
  • Multivitamin complexes to support the immune system.

Drinking plenty of fluids and infusion therapy (droppers) with glucose preparations are recommended to prevent dehydration in the treatment of symptoms of Dengue fever.

Diagnosis and treatment of Dengue fever in the clinic JSC “Medicina”

Having found signs of a dangerous disease after returning from the countries of the tropical region of Asia, immediately make an appointment with the infectious disease specialist of the clinic of JSC “Medicine”. It offers its own diagnostic center and an outpatient clinic, where you can undergo a treatment course under the supervision of a specialist. Each visitor is guaranteed an attentive attitude, confidentiality, a full range of necessary diagnostic and treatment procedures. Appointments are made online and by phone during business hours.

Questions and answers

How is dengue fever transmitted?

The source of infection is the blood of a sick person, monkeys or bats. When bitten by a mosquito of the genus Aedes, infected blood enters the body of an insect, where the infectious agent multiplies rapidly in favorable conditions for itself. When a healthy animal or person is bitten, the infection enters the body of the victim, where it soon makes itself felt with characteristic dangerous symptoms.

Why is dengue fever dangerous?

In the absence of timely medical attention, dengue fever can cause serious complications in the brain, nervous system and liver tissues. Patients may develop symptoms of the following diseases:

  • meningitis, encephalitis;
  • inflammation of the nerves;
  • state of acute psychosis;
  • otitis;
  • thrombophlebitis;
  • state of toxic shock.

For pregnant women, the disease is dangerous due to the risk of premature birth and intrauterine fetal hypoxia.

How is dengue fever diagnosed?

An examination by an infectious disease specialist is often enough to make a diagnosis of Dengue fever. The disease is indicated by characteristic signs – enlarged lymph nodes, a bright red rash, pain in the joints and muscles. To confirm the diagnosis, blood tests are carried out by polymerase chain reaction and serological methods. A biochemical blood test allows you to find out the degree of damage to internal organs.

“Unknown disease similar to dengue fever”: Rospotrebnadzor asked vacationers in Egypt to be careful 2 Soyuz

Fresh issue


17.07. 2023 15:28


Irina Nevinnaya

Rospotrebnadzor has strengthened sanitary and quarantine control over flights arriving from Egypt, the federal service reported today. This is due to several cases of an unknown disease, the symptoms of which resemble dengue fever.

Pavel Lvov / RIA Novosti

According to the Egyptian Ministry of Health and Population, an outbreak of an unknown fever was recorded in the province of Qena, 600 kilometers south of Cairo.

“In connection with the current situation regarding flights arriving from Egypt, Rospotrebnadzor has strengthened sanitary and quarantine control, including with the help of the Perimeter automated information system,” the federal service said today.

Precautions are necessary, as in case of any infection of unknown etiology, while local authorities and doctors will find out the nature of the disease.This is necessary in order to assess the risks of its cross-border spread.Depending on this, both in Egypt and in countries that have transport links with it, the necessary anti-epidemic measures will be taken .

What is known about dengue fever

Dengue fever is an infectious disease that is widespread in Southeast Asia (Thailand, Indonesia, China, Malaysia, Japan, Vietnam, Myanmar, Singapore, Philippines), India, Africa (Mozambique, Sudan , Egypt), in the tropical and subtropical zone of North, Central and South America (Mexico, Honduras, Costa Rica, Puerto Rico, Panama, Brazil, etc. ). About 50 million people in the world are infected with dengue every year.

Cases of the disease are also not uncommon in Russia. This fever is brought by tourists returning from vacations from endemic countries.

The main carriers of this vector-borne infection are Aedes aegypti mosquitoes.

An important detail: in the absence of a carrier, a sick person does not pose an epidemiological danger (that is, this infection is not transmitted by airborne droplets).

Rospotrebnadzor warns tourists planning their holidays in Egypt: in order to prevent infectious and parasitic diseases transmitted by insects, precautions must be taken:

  • wear clothing that covers the skin as much as possible,
  • use insect repellants and insecticides,
  • indoors – protect windows and doors with nets.

The incubation period for dengue fever lasts from 3 to 14 days, so you can get sick in a week or two after returning from vacation. Therefore, in case of symptoms, deterioration of health, you should consult a doctor, be sure to tell him where the person returned from.

Main symptoms of classic dengue fever

The disease may be asymptomatic, with mild symptoms, or severe disease.

Dengue fever is characterized by an acute onset: the temperature rises to 39-40 degrees. Then the state of health changes in waves: by the end of the third day, the temperature drops, after 1-3 days it rises again, then decreases after 2-3 days.

Other general signs: severe headache, swollen lymph nodes, eye pain, nausea, vomiting, pain in the back, muscles and joints, especially knees.

A characteristic symptom is a profuse, itchy rash on the trunk, later all over the body, legs and arms. The rash persists for 3-7 days and leaves behind peeling.

How dangerous is dengue fever

In most cases, recovery occurs within 7-10 days.

But in rare cases (from 0.5 to 6%), a severe hemorrhagic form of the disease can develop with emerging subcutaneous hemorrhages (bruises without bruises), nosebleeds, bleeding gums, vomiting and diarrhea with blood, internal bleeding.