**Patient Name:** Rizvi Mahmud Plabon  
**Age:** 33  
**Gender:** Male  
**Medical History:** Not specified (entry "dfgdfg" is not interpretable)  
**Presenting Symptom:** Headache

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### 1. Potential Differential Diagnoses

Given the limited information (isolated headache, no further history), the differential is broad and includes:

- **Primary Headache Disorders:**
  - Tension-type headache
  - Migraine (with or without aura)
  - Cluster headache

- **Secondary Headache Causes:**
  - Sinusitis
  - Medication overuse headache
  - Cervicogenic headache
  - Hypertension (especially if severe)
  - Infection (e.g., viral illness, meningitis)
  - Intracranial pathology (e.g., tumor, hemorrhage, venous sinus thrombosis)
  - Temporal arteritis (rare at this age, but consider if symptoms suggest)
  - Trauma-related headache

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### 2. Recommended Diagnostic Tests

**Initial Evaluation:**
- **Detailed history and physical/neurological examination** (to identify red flags and guide further workup)

**If no red flags and primary headache suspected:**
- No immediate tests required; consider headache diary

**If red flags or secondary headache suspected:**
- **Neuroimaging:** Non-contrast CT head (acute), MRI brain (subacute/chronic)
- **Laboratory tests:** CBC, ESR/CRP (if infection or temporal arteritis suspected)
- **Lumbar puncture:** If meningitis, subarachnoid hemorrhage, or idiopathic intracranial hypertension suspected
- **Sinus imaging:** If sinusitis suspected

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### 3. Urgency Level

- **Low** if headache is chronic, stable, and without red flags.
- **Medium to High** if any red flags are present (see below), or if new, severe, or sudden-onset headache.

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### 4. Key Observations and Clinical Notes

- **History is critical:** Onset, duration, character, location, associated symptoms (nausea, photophobia, visual changes, fever, neck stiffness, focal neurological deficits, altered mental status, trauma, etc.)
- **Examination:** Vital signs, fundoscopic exam (papilledema), full neurological exam, signs of meningeal irritation, sinus tenderness.
- **Medication and substance use:** Recent changes, overuse, withdrawal.
- **Family history:** Migraine, vascular disorders.

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### 5. Red Flags to Watch For

- Sudden onset ("thunderclap" headache)
- Worst headache of life
- New headache in patient >50 years old (not applicable here, but important)
- Headache with fever, neck stiffness, photophobia (meningitis/encephalitis)
- Headache with focal neurological deficits (stroke, mass lesion)
- Headache with altered mental status
- Headache with papilledema (raised intracranial pressure)
- Headache after trauma
- Headache with visual changes or jaw claudication
- Immunosuppression or cancer history

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**Summary:**  
With only "headache" as a symptom and no further history, the differential is broad. A detailed history and examination are essential to narrow the diagnosis and determine the need for urgent investigation. If any red flags are present, urgent evaluation and neuroimaging are warranted. If the headache is typical of a primary headache disorder and no red flags are present, outpatient management and follow-up may be appropriate.

**Recommendation:**  
Obtain a thorough history and perform a focused physical and neurological examination. Escalate care if any red flags are identified. Always advise the patient to seek immediate medical attention if symptoms worsen or new concerning features develop.