Fever, Headache: 78 Possible Causes
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What causes fever and headache? 78 possible conditions

See a list of possible causes in order from the most common to the least.


Common Cold Overview

The common cold is a virus that involves symptoms like sneezing, a runny nose and a headache. Learn the causes, symptoms and treatments for the common cold now!

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Cold and Flu Overview

Common colds and influenza are contagious infections that affect the respiratory system. Both are airborne illnesses, spread through coughing and sneezing. Shared symptoms include headache, cough, sore throat, and more.

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Sinus Infections (Sinusitis)

A sinus infection, or sinusitis, is a common condition that affects 30 million people in the United States each year, according to the National Institute of Allergy and Infectious Diseases. The infection occurs whe...

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Strep Throat

Strep throat is a bacterial infection that causes inflammation and pain in the throat. This common condition is caused by group A Streptococcus bacteria.

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Acute HIV Infection

Acute HIV infection occurs soon after someone is infected with HIV. Learn about acute HIV infection symptoms, diagnosis, treatment, and prevention.

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Swine Flu

Swine flu, or H1N1, is highly contagious and can spread quickly from person to person. A simple sneeze may cause thousands of germs to spread through the air. Symptoms are similar to regular influenza.

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Dengue Fever

Dengue fever is a disease that affects much of the tropical region and is caused by one of four dengue viruses. A skin rash between two and five days after the initial fever is a common symptom.

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Food Poisoning

This condition is considered a medical emergency. Urgent care may be required.

Food poisoning occurs when you consume foods contaminated with bacteria, viruses, or parasites. Symptoms are usually uncomfortable but not severe.

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Pneumonia is an infection of the lungs caused by fungi, bacteria, or viruses. General symptoms include chest pain, fever, cough, and difficulty breathing.

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Malaria is a life-threatening disease. It's typically transmitted through the bite of an infected Anopheles mosquito.

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This condition is considered a medical emergency. Urgent care may be required.

Meningitis is an inflammation of the meninges. This is the membrane that covers the brain and spinal cord. Meningitis may occur when fluid surrounding the meninges becomes infected. The most common causes of meningiti...

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Caffeine Overdose

The recommended amount of caffeine is usually 400 mg per day for healthy adults. Caffeine overdose may occur if you ingest more than this amount.

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Heat Emergencies

This condition is considered a medical emergency. Urgent care may be required.

Heat emergencies are health crises caused by exposure to hot weather and sun. Heat emergencies have three stages: heat cramps, heat exhaustion, and heatstroke.

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Tonsillitis can occur at any age and is a common childhood ailment. It is most often diagnosed in children from preschool age through their midteens.

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Infectious Mononucleosis

Infectious mononucleosis, or mono, refers to a group of symptoms usually caused by the Epstein-Barr virus (EBV).

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The Atypical Facts About Atypical Pneumonia

Pneumonia is an infection that causes inflammation of the lungs. Atypical pneumonia is a kind that isn't caused by the bacteria that causes typical pneumonia.

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Rhinitis is inflammation of your nasal cavity lining. It can be allergic or nonallergic. It also may be infectious.

Allergic rhinitis can occur when you breathe in something that you're allergic to, known a...

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Pharyngitis is inflammation of the pharynx, which is in the back of the throat. It's most often referred to simply as "sore throat" and is very common.

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CFS (Chronic Fatigue Syndrome)

Chronic fatigue syndrome (CFS) is a debilitating disorder characterized by extreme tiredness that can't be explained by an underlying medical condition.

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Also known as varicella, chickenpox is a virus that often affects children. It is characterized by itchy, red blisters that appear all over the body.

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This feature is for informational purposes only and should not be used to diagnose.
Please consult a healthcare professional if you have health concerns.