Having a fever for 15 days with chills, headache, weakness, and poor appetite despite treatment suggests the need for thorough evaluation to identify the cause.

🧪 Initial Blood Tests to Consider

• Complete blood count (CBC) to check for infection or anemia.
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) to assess inflammation.
• Liver and kidney function tests to evaluate organ health.

🧪 Infection-Specific Tests

• Blood cultures to detect bacterial infections.
• Malaria test and dengue serology if relevant to your area or exposure.
• Typhoid tests such as Widal or Typhidot based on symptoms and local prevalence.

🩻 Additional Investigations

• Chest X-ray to rule out lung infections.
• Urine analysis to check for urinary tract infections.

💊 Treatment Guidance

• Avoid self-medicating further; treatment depends on the diagnosis.
• Specific therapies like antibiotics or antivirals may be needed once the cause is identified.

⚠️ When to Seek Urgent Care

• If you develop persistent high fever, difficulty breathing, confusion, or worsening weakness, seek immediate medical attention.

Please consult an infectious disease specialist or your primary care doctor promptly for detailed evaluation and tailored treatment.To narrow down potential causes, we will need some more information.I understand you've been dealing with a recurring fever, headaches, weakness, and poor appetite for 15 days without improvement. To help figure out what's going on, could you please provide your age and gender?