Headaches, Dizziness, and Fatigue: Potential Causes & When to See a Doctor

This triad of symptoms is nonspecific and can arise from numerous conditions across multiple systems.

Potential Causes by Category

Hematologic / Nutritional

• Anemia (iron deficiency, B12/folate deficiency)

Endocrine / Metabolic

• Thyroid dysfunction (hypo- or hyperthyroidism)
• Diabetes (hyper-/hypoglycemia)
• Electrolyte imbalances

Neurologic

• Migraine (vestibular migraine can cause dizziness without headache)
• Chronic fatigue syndrome / myalgic encephalomyelitis
• Multiple sclerosis, other demyelinating conditions

Cardiovascular / Respiratory

• Orthostatic hypotension, arrhythmias
• Sleep apnea (causes non-restorative sleep, morning headache, fatigue)
• COPD, pulmonary hypertension

Psychiatric / Behavioral

• Anxiety, depression, somatic symptom disorder
• Chronic stress, burnout

Other

• Medication side effects (especially antihypertensives, sedatives, opioids)
• Chronic infections (EBV, Lyme, HIV)
• Autoimmune disorders (lupus, Sjögren’s)
• Ménière’s disease (episodic vertigo, hearing loss, tinnitus)
• Environmental: carbon monoxide, mold, allergens

Recommended Next Steps

1. See a primary care physician for history, physical, and basic labs (CBC, CMP, TSH, iron studies, B12/folate, HbA1c).
2. Consider sleep study if snoring/witnessed apneas; EKG/Holter if palpitations; brain MRI if focal neuro signs.
3. Track symptoms in a diary: timing, triggers, severity, associated features.

Treatment depends entirely on the underlying diagnosis. Do not self-medicate chronically; identify and address the root cause.