From the Guidelines
For fatigue, dizziness, and brain fog, I recommend a comprehensive lab workup including complete blood count (CBC), comprehensive metabolic panel (CMP), thyroid function tests (TSH, free T4), vitamin levels (B12, folate, vitamin D), iron studies (ferritin, iron, TIBC), inflammatory markers (ESR, CRP), and hemoglobin A1C, as suggested by the most recent guidelines 1. These symptoms often stem from multiple potential causes including anemia, thyroid dysfunction, vitamin deficiencies, blood sugar abnormalities, or autoimmune conditions. The CBC can identify anemia or infection, while thyroid tests detect hypothyroidism which commonly causes these symptoms. Vitamin deficiencies, particularly B12 and D, frequently contribute to fatigue and cognitive issues. Iron deficiency, even without anemia, can cause fatigue and brain fog. Blood sugar imbalances detected through glucose and A1C testing may reveal diabetes or prediabetes. If these initial tests are normal, further evaluation for chronic fatigue syndrome, fibromyalgia, sleep disorders, or mental health conditions may be warranted. It's essential to track symptoms alongside testing to help identify patterns and potential triggers, and to consider a multi-tiered and individualized approach to laboratory testing, as recommended by recent guidelines 1. Additional tests to consider include cortisol levels, Lyme disease testing, autoimmune panels, and sleep studies if indicated. The diagnostic yield of imaging studies such as CT or MRI is generally low in patients with isolated dizziness or fatigue, and these tests should be used judiciously, based on clinical judgment and patient risk factors 1. A thorough history and physical examination, as well as a review of systems, are crucial in evaluating patients with fatigue, dizziness, and brain fog, and in guiding further testing and management 1.
From the Research
Fatigue
- Fatigue is a common symptom that can be caused by a variety of factors, including sleep disorders, depression, and excessive psychosocial stress 2, 3.
- Investigations beyond a thorough history, physical examination, and simple laboratory tests are typically not needed unless additional symptoms or findings are present 2.
- Treatment of fatigue should include a structured plan for regular physical activity, such as walking, and may also involve cognitive behavior therapy, exercise therapy, and acupuncture 3, 4.
Dizziness
- Dizziness is a common yet imprecise symptom that can be caused by a variety of factors, including benign paroxysmal positional vertigo, Meniere disease, and vestibular neuritis 5.
- Evaluation of dizziness focuses on determining whether the etiology is peripheral or central, with peripheral etiologies typically being benign and central etiologies often requiring urgent treatment 5.
- The HINTS (head-impulse, nystagmus, test of skew) examination can help distinguish peripheral from central etiologies, and treatment may involve a canalith repositioning procedure, salt restriction, diuretics, vestibular suppressant medications, and vestibular rehabilitation 5.
Brain Fog
- Brain fog is a lay term used to describe cognitive difficulties that can be caused by a variety of factors, including lack of sleep, poor nutrition, medications, and neuroinflammation 6.
- Chronic low-level inflammation is thought to be a major contributor to brain fog, and treatment may involve pharmacological and nonpharmacological interventions aimed at reducing inflammation and improving functioning 6.
- There is currently a lack of evidence for specific treatments targeting the mechanisms/pathways of neuroinflammation for precision-based care, but interventions such as cognitive behavior therapy and exercise therapy may be helpful in reducing symptoms of brain fog 6, 4.