**Patient Information:**  
Name: Mr Patient  
Age: 13 years  
Gender: Male  
Medical History: Not specified (text "dfgdfg" is non-informative)

**Presenting Symptom:**  
Headache

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### 1. Potential Differential Diagnoses

In a 13-year-old male with headache and no further history provided, consider the following common and serious causes:

- **Primary Headache Disorders:**
  - Migraine (with or without aura)
  - Tension-type headache
  - Cluster headache (less common in this age group)

- **Secondary Headache Causes:**
  - Viral or bacterial infection (e.g., sinusitis, upper respiratory tract infection, meningitis)
  - Medication overuse headache
  - Head trauma/concussion
  - Vision problems (refractive errors, eye strain)
  - Dehydration
  - Sleep disturbances
  - Intracranial pathology (e.g., mass lesion, hydrocephalus, idiopathic intracranial hypertension)
  - Hypertension
  - Dental issues (e.g., temporomandibular joint dysfunction)

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### 2. Recommended Diagnostic Tests

**Initial Evaluation:**
- **History and Physical Examination:**  
  - Detailed headache history (onset, duration, location, quality, associated symptoms, triggers, relieving factors, family history)
  - Neurological examination
  - Vital signs (including blood pressure)

**Further Investigations (if indicated by history/exam):**
- **Laboratory Tests:**  
  - CBC, CRP/ESR (if infection or inflammation suspected)
- **Imaging:**  
  - Brain MRI or CT (if red flags present or abnormal neurological findings)
- **Other:**  
  - Ophthalmologic evaluation (if visual symptoms or papilledema suspected)
  - Lumbar puncture (if meningitis or raised intracranial pressure suspected)

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### 3. Urgency Level

**Medium**  
- Most pediatric headaches are benign, but a thorough assessment is needed to rule out serious causes.
- Urgency increases to **High** if any red flags (see below) are present.

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### 4. Key Observations and Clinical Notes

- **Age-appropriate causes:** Migraine and tension-type headaches are common in adolescents.
- **Lack of detailed history:** Unable to assess chronicity, associated symptoms (e.g., fever, vomiting, photophobia, neck stiffness), or precipitating factors.
- **No medical history provided:** Unknown risk factors or comorbidities.
- **No mention of trauma or systemic symptoms.**
- **No neurological findings provided.**

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### 5. Red Flags to Watch For

Immediate evaluation is warranted if any of the following are present:

- Sudden, severe ("worst ever") headache
- Headache with fever, neck stiffness, photophobia (meningitis/encephalitis)
- Altered mental status, seizures, or focal neurological deficits
- Papilledema or visual changes
- Headache worse with Valsalva, lying down, or in the morning (raised intracranial pressure)
- Recent head trauma
- Persistent vomiting
- Immunosuppression or known malignancy
- Age <6 years with new severe headache

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**Summary:**  
A 13-year-old male with headache requires a detailed history and physical exam to guide further workup. Most headaches in this age group are benign, but red flags must be excluded. If any concerning features are present, urgent neuroimaging and specialist referral are indicated.

**Recommendation:**  
Consult a healthcare professional for a comprehensive evaluation. If any red flags develop, seek immediate medical attention.