Chronic Fatigue Evaluation in Doral, FL

What Counts as Clinical Fatigue

Everyone gets tired. Clinical fatigue is different — it is fatigue that does not improve with rest, that is disproportionate to recent exertion, and that interferes with work, family, or daily activities. The distinction between subtypes matters because it guides the workup:

• Acute fatigue: less than 1 month — usually viral, post-surgical, or medication-related; often self-resolving
• Subacute fatigue: 1 to 6 months — warrants a structured workup; common causes include anemia, thyroid, depression, sleep disorder
• Chronic fatigue: more than 6 months — broader differential including autoimmune, post-viral, ME/CFS, occult malignancy
• Post-exertional malaise: worsening of all symptoms after physical, mental, or emotional effort — a hallmark feature of ME/CFS
• Daytime sleepiness vs. fatigue: sleepiness is the urge to sleep; fatigue is exhaustion without the urge — they have different workups

Common Medical Causes We Look For

Fatigue has at least 20 well-described medical causes. Our evaluation is built to identify the ones that account for the majority of cases without ordering unnecessary tests. Per the AAFP fatigue guideline, the highest-yield categories are:

• Iron-deficiency anemia — especially common in menstruating women, vegetarians, frequent blood donors, and those with GI blood loss
• Vitamin B12 deficiency — vegetarians, vegans, adults over 60, patients on long-term acid-suppression therapy
• Thyroid dysfunction — both hypothyroidism and hyperthyroidism cause fatigue; checked with TSH and free T4
• Obstructive sleep apnea — present in 26% of adults aged 30–70 (NHLBI); often missed because partners and patients normalize snoring
• Depression and anxiety — depression is the single most common cause of chronic fatigue in primary care; screened with PHQ-9 and GAD-7
• Uncontrolled diabetes or prediabetes — fatigue is one of the most common presenting symptoms
• Chronic kidney disease and liver disease — checked on a comprehensive metabolic panel
• Chronic infection — post-viral syndromes (including post-COVID), chronic Lyme, mononucleosis reactivation
• Autoimmune disease — lupus, rheumatoid arthritis, Sjögren syndrome
• Medication side effects — antihistamines, blood pressure agents, opioids, gabapentinoids, some psychiatric medications
• Occult malignancy — rare but important to rule out in unexplained weight loss with fatigue

The Lab Workup We Order

A targeted lab panel covers about 80% of clinically actionable fatigue causes. We order the panel that fits your history, not a shotgun. The standard fatigue workup typically includes:

• Complete blood count (CBC) — screens for anemia and infection
• Ferritin and iron studies — ferritin is more sensitive than hemoglobin for early iron deficiency
• Thyroid stimulating hormone (TSH), with free T4 if TSH abnormal
• Vitamin B12 and folate
• Vitamin D 25-OH
• Comprehensive metabolic panel (CMP) — kidney, liver, electrolytes, glucose, calcium
• Hemoglobin A1c — screens for prediabetes or undiagnosed diabetes
• Hs-CRP or ESR — screens for systemic inflammation
• Pregnancy test for women of reproductive age (when relevant)
• Additional testing when history suggests it — sleep study, autoimmune panel (ANA, RF), HIV, hepatitis, EBV titers, cortisol

Sleep Apnea — The Most Missed Cause of Fatigue

Per the NIH NHLBI, obstructive sleep apnea affects roughly 26% of US adults aged 30 to 70 and is undiagnosed in an estimated 80% of those cases. Untreated OSA fragments sleep architecture, drops oxygen levels overnight, raises blood pressure and cardiovascular risk, and produces exactly the fatigue that brings patients to primary care. Per the American Thoracic Society, in-home sleep apnea testing is appropriate for adults with moderate-to-high pre-test probability and no major cardiopulmonary comorbidity. We use the STOP-BANG questionnaire at intake to identify patients who need testing, and arrange home sleep apnea testing in-network when indicated. Treatment — CPAP, oral appliance, positional therapy, or weight loss — is often what finally resolves chronic fatigue.

Iron Deficiency — Especially in Women

Iron-deficiency anemia and iron deficiency without anemia are some of the most common — and most missed — causes of fatigue in adult women. Menstruating women lose iron monthly; pregnancy and lactation increase demand; gastrointestinal blood loss can cause it in either sex. Checking hemoglobin alone is not enough; ferritin is the more sensitive early marker. A ferritin under 30 ng/mL (and sometimes under 50) is consistent with iron deficiency even when hemoglobin remains in the normal range. Treatment is straightforward — oral iron replacement with vitamin C, or IV iron when oral is not tolerated or absorbed — and patients often feel meaningfully better within 4 to 6 weeks.

When Fatigue Is ME/CFS

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a serious, chronic, multi-system disease that the CDC estimates affects up to 2.5 million Americans (CDC 2024), most of whom are undiagnosed. The diagnostic criteria require fatigue lasting more than 6 months, post-exertional malaise, unrefreshing sleep, and either cognitive impairment or orthostatic intolerance. ME/CFS often follows a viral illness — including COVID — and management focuses on pacing, sleep optimization, treatment of overlapping conditions, and avoiding the graded-exercise-therapy approaches that have been shown to worsen symptoms. We evaluate ME/CFS using the IOM/NAM criteria, rule out alternative causes, and coordinate care for the multisystem features.

Mental Health and Fatigue

Depression is the single most common cause of unexplained fatigue in primary care, and anxiety frequently coexists. We screen every fatigue patient with the PHQ-9 and GAD-7 at intake. When fatigue is driven by depression, treating the depression — with therapy, exercise, light exposure, and when appropriate, in-network psychiatry — typically resolves the fatigue as well. We do not assume fatigue is depression without ruling out medical causes first, and we do not dismiss medical fatigue as 'just stress.'

What the First Visit Looks Like

• Detailed history — onset, course, severity, post-exertional malaise, sleep, mood, medications, recent illnesses, family history
• Targeted physical exam — vitals, thyroid, lymph nodes, neurologic, mental status
• Screening questionnaires — STOP-BANG, PHQ-9, GAD-7
• Lab order based on what your history suggests — not a shotgun
• Plan for what comes next: home sleep study if indicated, follow-up to review labs, referral if a specific differential is identified
• Telehealth follow-ups for lab review and medication management once a plan is in place

Bilingual, Same-Day Access

• Same-day evaluation typically available — call (305) 209-0001
• Visits delivered fully in English or Spanish — intake, exam, lab review, telehealth follow-up
• In-network with Oscar Health, Aetna, Cigna, Humana, Medicare Advantage, Ambetter, UnitedHealthcare
• On-site phlebotomy through the laboratory — most labs drawn at the same visit
• Coordination with sleep medicine, endocrinology, and psychiatry when indicated