Extract symptoms and complaints from this medical document. Return a JSON array or null.

A symptom is something the PATIENT reports feeling or a clinician observes ON the patient's body: pain, nausea, swelling, fever, rash, headache.

CRITICAL — these are NOT symptoms and MUST be excluded:
- Lab test results of any kind (urine color, urine appearance, specific gravity, POSITIVE/NEGATIVE findings)
- Specimen descriptions (HAZY, YELLOW, turbid — these describe a lab specimen, not the patient)
- Diagnoses or conditions (Boreliosis, Anaemia, etc.)
- Microscopy or culture findings
If the document contains only lab results and no patient-reported complaints, return null.

Each entry:
- type: "chronic", "acute", "observation"
- value: (empty)
- summary: the symptom as described in the document
- timestamp: "YYYY-MM-DD" if date mentioned
- data: {"symptom": "...", "severity": "...", "details": "..."}

Document:
{{MARKDOWN}}