Differential Diagnosis for Chills and Headache
- Single most likely diagnosis:
- Viral upper respiratory infection (e.g., common cold, flu): This is a common condition that often presents with chills, headache, and other symptoms such as cough, sore throat, and runny nose. The high prevalence of these infections in the general population makes them a likely cause of these symptoms.
- Other Likely diagnoses:
- Bacterial sinusitis: This condition can cause headache and chills, especially if the sinuses become infected. It often follows a viral upper respiratory infection.
- Influenza: While included in the broader category of viral upper respiratory infections, influenza can be more severe and is worth considering separately, especially during flu season.
- Meningitis: Although less common, meningitis is an infection of the protective membranes covering the brain and spinal cord and can present with headache and chills, along with fever, stiff neck, and confusion.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Meningitis (as mentioned, due to its severity and potential for serious complications or death if not promptly treated).
- Encephalitis: An inflammation of the brain tissue, usually caused by viral infections. It can present with headache, chills, fever, confusion, and sometimes seizures or difficulties with speech and movement.
- Sepsis: A life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. Early signs can be non-specific, including chills, headache, and fever.
- Rare diagnoses:
- Brain abscess: A rare and potentially life-threatening condition where a pocket of pus forms in the brain, often as a result of a bacterial or fungal infection. Symptoms can include headache, chills, fever, and neurological deficits.
- Subarachnoid hemorrhage: Although typically presenting with a sudden, severe headache, it can sometimes be preceded by less severe headaches or other non-specific symptoms like chills, especially if there is a warning leak.
- Lyme disease (in endemic areas): Caused by the bacterium Borrelia burgdorferi, transmitted to humans through the bite of infected black-legged ticks. Early stages can present with non-specific symptoms such as headache and chills, along with a characteristic rash.