Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: September 17, 2025 • View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Differential Diagnosis for a 25-year-old Male with Cough, Fever, and Vomiting

Single Most Likely Diagnosis

  • Influenza or Viral Pneumonia: This is the most likely diagnosis given the symptoms of cough, fever, and vomiting, which are common presentations of influenza or viral pneumonia, especially during flu season. The duration of the cough for about three weeks could indicate a secondary bacterial infection complicating the initial viral illness.

Other Likely Diagnoses

  • Bacterial Pneumonia: This could be a primary infection or a secondary complication of an initial viral infection. Symptoms such as cough, fever, and vomiting are consistent with bacterial pneumonia, which can range from mild to severe.
  • Gastroenteritis with Secondary Respiratory Symptoms: Although the primary symptoms suggest a respiratory infection, gastroenteritis (often caused by viruses or bacteria) can lead to vomiting, which might be accompanied by a cough if the patient aspirates vomit or if there's an associated viral upper respiratory infection.

Do Not Miss Diagnoses

  • Pulmonary Embolism: Although less common in a young adult without obvious risk factors, pulmonary embolism can present with sudden onset of cough, fever (if there's associated pneumonia or infarction), and vomiting (due to pain or systemic response). It's crucial to consider this diagnosis due to its high mortality if untreated.
  • Tuberculosis (TB): TB can present with chronic cough, fever, and systemic symptoms like vomiting, especially if there's significant pulmonary involvement. Given the three-week duration of symptoms, TB becomes a consideration, particularly if the patient has risk factors such as exposure history or immunocompromised status.

Rare Diagnoses

  • Q Fever: Caused by Coxiella burnetii, Q fever can present with flu-like symptoms including cough, fever, and gastrointestinal symptoms like vomiting. It's more common in individuals with exposure to livestock but should be considered in the differential of a patient with a prolonged and undiagnosed febrile illness.
  • Histoplasmosis: This fungal infection can cause respiratory symptoms, fever, and systemic illness, including gastrointestinal symptoms. It's more likely in individuals who have been exposed to bird or bat droppings, but it can be considered in a differential diagnosis for a patient with a prolonged febrile illness and respiratory symptoms, especially if other common causes have been ruled out.

Related Questions

Do blood pressure (BP) measurements 10 days after cervical spine surgery accurately indicate likely baseline blood pressures (BPs) pre-surgery?
What is the initial approach to managing sinus tachycardia in a patient without underlying conditions or symptoms?
What are the oral treatment options for dengue?
How do I rule out the top three differential diagnoses?
Can I prescribe atorvastatin (statin) to a 15-year-old?
What is the best treatment for a patient with diffuse lymphadenopathy, suspected myeloproliferative neoplasm (MPN), anemia (low hemoglobin), leukocytosis (markedly elevated leukocytes), thrombocytopenia (low platelets), and a blood smear showing excess neutrophils and basophils?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question