What could be causing daily headaches on the left side of my head with numbness?

Daily Left-Sided Headache with Numbness: Evaluation and Management

You need urgent neurological evaluation with neuroimaging because daily unilateral headache with numbness represents a red flag symptom that requires exclusion of serious secondary causes before considering primary headache disorders.

Immediate Concerns and Red Flags

Your presentation contains concerning features that mandate prompt evaluation:

• Numbness is a focal neurological symptom that significantly elevates concern for secondary headache disorders including structural lesions, stroke, or other serious pathology 1
• Daily headaches suggest either chronic migraine, medication overuse headache, or an underlying structural problem requiring investigation 1
• Unilateral location with neurological symptoms warrants neuroimaging even in the absence of other abnormal examination findings 1

When Neuroimaging is Required

Neuroimaging should be obtained in your case because you have focal neurological symptoms (numbness) accompanying your headache 1. The American Academy of Neurology guidelines specifically recommend neuroimaging for patients with atypical headache patterns or neurologic signs 1.

Additional red flags that would further support urgent imaging include 1, 2:

• Rapidly increasing headache frequency
• Headache that awakens you from sleep
• Abrupt onset or marked change in headache pattern
• Any impairment of consciousness
• Worsening with Valsalva maneuver

MRI of the brain is the preferred imaging modality for non-emergent evaluation of headaches with concerning features like yours 2.

Differential Diagnosis to Consider

Primary Headache Disorders

Migraine with aura can present with unilateral headache and sensory symptoms 1:

• Sensory aura occurs in ~31% of migraine with aura patients, typically as unilateral paresthesia (pins and needles/numbness) that spreads gradually in the face or arm 1
• However, aura symptoms should be fully reversible and typically last 5-60 minutes, not persist daily 1
• Daily occurrence makes this diagnosis less likely unless transformed to chronic migraine 1

Chronic migraine is defined as headache occurring ≥15 days per month for >3 months 1:

• Can present with unilateral pain 1
• However, persistent numbness is not typical and requires exclusion of structural causes first 1

Secondary Headache Disorders (Must Exclude First)

Given your focal neurological symptom (numbness), serious causes must be ruled out 1, 2:

• Structural lesions (tumor, arteriovenous malformation)
• Stroke or transient ischemic attack
• Temporal arteritis (especially if age >50 years) 3, 4
• Subdural hematoma (especially with any history of head trauma) 3

Medication Overuse Headache

If you are taking acute headache medications (analgesics, triptans, NSAIDs) more than twice weekly, medication overuse headache (MOH) must be considered 1, 5:

• MOH causes increasing headache frequency, potentially resulting in daily headaches 5
• Withdrawal of overused medication is the necessary remedy 1
• However, numbness is not explained by MOH alone and still requires investigation 1

Recommended Evaluation Pathway

Step 1: Urgent Neurological Assessment

• Complete neurological examination focusing on sensory deficits, motor function, cranial nerves, and signs of increased intracranial pressure 1
• Detailed headache history including onset, character, timing, associated symptoms, and medication use 1

Step 2: Neuroimaging

• MRI brain with and without contrast is indicated given your focal neurological symptoms 2
• This should be obtained promptly, within days to weeks depending on severity of symptoms 1

Step 3: Additional Testing if Indicated

• ESR/CRP if age >50 to evaluate for temporal arteritis 3, 4
• Lumbar puncture only if imaging suggests infection, inflammation, or if subarachnoid hemorrhage is suspected 2

Critical Pitfalls to Avoid

• Do not assume this is migraine without first excluding secondary causes, given the presence of numbness 1
• Do not delay imaging in the presence of focal neurological symptoms 1, 2
• Do not overlook medication overuse if you are taking frequent acute medications, but recognize this does not explain the numbness 1, 5
• Do not miss temporal arteritis if you are over age 50, as this can lead to permanent vision loss if untreated 3, 4

Next Steps

Seek evaluation by a neurologist within 2-4 weeks if you can care for yourself, or within 48 hours if symptoms are significantly impacting your function 1. If you develop sudden worsening, thunderclap headache, vision changes, weakness, or altered consciousness, seek emergency evaluation immediately 2, 4.