Short answer: No, constant fatigue is not normal—it’s your body’s way of telling you something is wrong.
If you wake up exhausted despite 7-8 hours of Sleep, need multiple coffees just to function, and can barely keep your eyes open by 2 PM, you’re not lazy or getting old. Something physiological is happening, and as a board-certified geriatric pharmacist and nutrition coach, I can help you identify what.
Constant fatigue affects over 40% of women over 40, but it’s so common that both patients and doctors dismiss it as “just part of Aging” or “being busy.” This is dangerous thinking that allows underlying conditions to go undiagnosed and untreated for years.
Let me walk you through the 12 most common medical reasons for persistent fatigue—and what to do about each one.
What “Normal” Tiredness Actually Looks Like
Before we dive into what’s wrong, let’s establish what’s normal:
Normal tiredness:
Feeling sleepy at bedtime
Needing 7-9 hours of sleep nightly
Occasional afternoon slump (manageable with brief rest or movement)
Fatigue after intense physical exertion
Tiredness that improves with adequate sleep
Abnormal tiredness (what we’re addressing):
Waking up exhausted after full night’s sleep
Constant, unrelenting fatigue regardless of rest
Inability to function without multiple coffees
Needing naps daily just to survive
Fatigue that interferes with work, Relationships, or daily activities
Brain fog, difficulty concentrating
Physical exhaustion from minimal activity
If the second list describes your daily reality, keep reading.
Reason #1: Thyroid Dysfunction
How common: Affects 1 in 8 women, especially over 40
What’s happening: Your thyroid gland produces hormones that regulate metabolism, energy production, and virtually every cell in your body. When production is too low (hypothyroidism), everything slows down.
The pharmacist’s insight: This is the most commonly missed cause of fatigue because doctors often only test TSH (thyroid stimulating hormone) and consider anything in the “normal range” (0.5-4.5) acceptable. But many women feel terrible until their TSH is below 2.0.
Other symptoms to watch for:
Weight gain despite no dietary changes
Cold intolerance (always freezing)
Hair thinning or loss
Dry skin
Constipation
Depression or brain fog
Irregular periods
What to do:
Request comprehensive thyroid panel: TSH, Free T3, Free T4, Reverse T3, thyroid antibodies
Don’t accept “your thyroid is fine” based only on TSH
If diagnosed, work with your doctor on optimal medication dosing (not just “normal” levels)
Consider that you may need T3 supplementation, not just T4 (levothyroxine)
Medication note: If you’re on thyroid medication and still tired, timing matters. Take it on an empty stomach, 30-60 minutes before eating, and separate from calcium, iron, and coffee by at least 4 hours.
Reason #2: Iron Deficiency or Anemia
How common: 1 in 5 women of childbearing age, increases with heavy periods and Menopause transition
What’s happening: Iron is essential for producing hemoglobin, which carries oxygen to your cells. Without adequate oxygen delivery, every system struggles.
The pharmacist’s insight: “Normal” ferritin levels for labs (12-150 ng/mL) don’t reflect optimal function. Most women feel their best with ferritin above 50-70 ng/mL. I’ve seen countless women with ferritin of 15-20 told they’re “fine” while feeling completely exhausted.
Other symptoms:
Shortness of breath with minimal exertion
Pale skin
Cold hands and feet
Brittle nails
Dizziness or lightheadedness
Rapid heartbeat
Restless leg syndrome
What to do:
Get comprehensive iron panel: ferritin, serum iron, TIBC, transferrin saturation, CBC
If deficient, identify the cause (heavy periods, poor absorption, dietary insufficiency, internal bleeding)
Supplementation strategy: Iron bisglycinate (gentler than ferrous sulfate), 25-50mg daily
Take with vitamin C (enhances absorption)
Separate from calcium, coffee, tea by 2+ hours
Recheck levels in 8-12 weeks
Warning: Never supplement iron without testing first. Excess iron is toxic and can cause serious Health problems.
Reason #3: Vitamin D Deficiency
How common: 40% of Americans, higher in women over 40
What’s happening: Vitamin D isn’t just for bones—it’s involved in energy production, mood regulation, immune function, and muscle strength. Deficiency causes profound fatigue that people often attribute to other causes.
The pharmacist’s perspective: Labs consider anything above 30 ng/mL “sufficient,” but research and clinical experience show optimal energy levels occur at 50-70 ng/mL.
Other symptoms:
Muscle weakness or aches
Bone pain
Frequent infections
Depression or mood changes
Hair loss
Poor wound healing
What to do:
Test 25-hydroxy vitamin D levels
If deficient, supplement with vitamin D3 (not D2) with K2 and magnesium as cofactors
Dosing depends on your level but typically 2,000-5,000 IU daily
Take with food containing fat for absorption
Retest in 3-6 months
Get sensible sun exposure (15-20 minutes daily without sunscreen when possible)
Reason #4: Vitamin B12 Deficiency
How common: 15% of adults over 60, but common in younger adults with digestive issues or on certain medications
What’s happening: B12 is critical for energy production, nerve function, and red blood cell formation. Deficiency develops slowly, often over years, causing gradual energy decline people attribute to aging.
The pharmacist’s critical knowledge: Many medications deplete B12:
Metformin (Diabetes drug)
Proton pump inhibitors/PPIs (omeprazole, pantoprazole)
H2 blockers (ranitidine, famotidine)
Antacids
Methotrexate
Other symptoms:
Numbness or tingling in hands/feet
Balance problems
Memory issues or confusion
Pale or jaundiced skin
Swollen, red tongue
Depression
What to do:
Test B12 levels (optimal >500 pg/mL, not just >200)
Consider testing methylmalonic acid (MMA) for functional B12 deficiency
If deficient, sublingual methylcobalamin 1000-2000 mcg daily (better absorbed than cyanocobalamin)
If severely deficient, may need B12 injections initially
Address absorption issues (low stomach acid, digestive disorders)
Age factor: After 50, stomach acid production decreases, reducing B12 absorption from food. Supplementation becomes increasingly important.
Reason #5: Sleep Apnea
How common: 25% of women over 40, dramatically increases after menopause
What’s happening: You stop breathing repeatedly throughout the night, causing oxygen drops and sleep fragmentation. Your brain partially wakes you to resume breathing, but you don’t remember these wakings. You think you slept 8 hours, but you got minimal restorative sleep.
Why it’s missed: Most doctors associate sleep apnea with overweight men who snore. Women present differently—often normal weight, milder symptoms, more fatigue and depression than obvious snoring.
Other symptoms:
Loud snoring (though not always)
Gasping or choking during sleep
Morning headaches
Dry mouth upon waking
Difficulty concentrating
Irritability or mood changes
High blood pressure resistant to medication
What to do:
Sleep study (in-lab or home version)
If diagnosed, CPAP Therapy is gold standard
Weight loss can help (but thin people get sleep apnea too)
Avoid alcohol before bed (relaxes throat muscles)
Sleep on your side, not back
Treat nasal congestion
Game-changer: Successful sleep apnea treatment often resolves fatigue within days to weeks. This can be life-changing.
Reason #6: Chronic Inflammation
How common: Increasingly prevalent with age, Diet, Stress, and environmental factors
What’s happening: Persistent low-grade inflammation throughout your body diverts energy to immune responses rather than daily function. It’s like running a low fever constantly—exhausting.
The pharmacist’s understanding: Many medications suppress symptoms but don’t address root inflammation. Meanwhile, Lifestyle factors continuously fuel the inflammatory fire.
Other symptoms:
Joint pain or stiffness
Digestive issues
Frequent infections
Brain fog
Skin problems (eczema, psoriasis)
Allergies or sensitivities
Autoimmune conditions
What to do:
Test markers: CRP, ESR, homocysteine
Identify triggers: food sensitivities, gut dysbiosis, chronic infections, environmental toxins
Anti-inflammatory diet: eliminate processed foods, sugar, excessive omega-6 oils
Increase omega-3s (fatty fish, fish oil)
Manage stress (cortisol fuels inflammation)
Prioritize sleep (inflammation repair happens during sleep)
Consider elimination diet to identify food triggers
Reason #7: Blood Sugar Dysregulation
How common: 1 in 3 adults have prediabetes, many undiagnosed; even more have reactive hypoglycemia
What’s happening: Blood sugar spikes and crashes throughout the day create energy roller coasters. High insulin levels (from insulin resistance) also directly cause fatigue.
The pharmacist’s clinical observation: This is epidemic in midlife women but rarely diagnosed because fasting glucose appears “normal” (under 100). The problem is what happens AFTER eating.
Other symptoms:
Crashes 1-2 hours after eating (especially carb-heavy meals)
Intense sugar or carb cravings
Shakiness, irritability when hungry (“hangry”)
Difficulty concentrating between meals
Weight gain, especially abdominal
Frequent urination
Increased thirst
What to do:
Test fasting glucose AND hemoglobin A1c
Consider glucose tolerance test or continuous glucose monitor for 2 weeks
Balance meals with protein (25-30g), healthy fats, fiber
Reduce refined carbohydrates and sugar
Eat every 4-5 hours (don’t skip meals)
Walk 10-15 minutes after meals (improves glucose clearance)
Strength train 3-4x weekly (builds insulin-sensitive muscle)
This was my post-meal fatigue blog topic—the connection is strong and often missed.
Reason #8: Medication Side Effects
How common: Extremely—the average 50-year-old woman takes 3-5 prescription medications, many of which cause fatigue
What’s happening: Medications affect neurotransmitters, metabolism, nutrient absorption, and sleep architecture. The effect compounds when taking multiple medications.
The pharmacist’s unique expertise: This is where my background becomes essential. Common fatigue-causing medications include:
Blood pressure medications:
Beta-blockers (metoprolol, atenolol) – directly cause fatigue and reduce Exercise tolerance
Clonidine – sedating
Antidepressants/Anxiety medications:
SSRIs (though can improve energy if treating depression)
Benzodiazepines (lorazepam, alprazolam) – sedating, disrupt sleep architecture
Trazodone – causes next-day grogginess
Antihistamines:
Diphenhydramine (Benadryl) – sedating for 12+ hours
First-generation antihistamines in sleep aids, cold medicines
Pain medications:
Opioids – sedating, disrupt sleep
Muscle relaxants – cause significant drowsiness
Gabapentin – fatigue is common side effect
Statins:
Can cause muscle pain and fatigue
May reduce CoQ10 (energy-producing compound)
Others:
Proton pump inhibitors (reduce B12 absorption)
Metformin (reduces B12)
Antiseizure medications
Medications for overactive bladder
What to do:
Review all medications with pharmacist or doctor
Never stop medications without medical guidance
Ask about alternative options with fewer side effects
Optimize dosing timing (take sedating meds at bedtime)
Address whether you still need all medications
Supplement nutrients depleted by medications
Reason #9: Adrenal Dysfunction
How common: Controversial topic, but HPA axis dysregulation affects many chronically stressed individuals
What’s happening: Chronic stress disrupts your hypothalamic-pituitary-adrenal (HPA) axis—the system regulating cortisol and stress response. While “adrenal fatigue” isn’t recognized medically, HPA axis dysfunction absolutely exists.
The science: Your adrenals don’t “fatigue,” but chronic stress can dysregulate cortisol patterns:
High cortisol at night (disrupts sleep)
Low cortisol in morning (can’t wake up)
Flat cortisol curve throughout day (no energy peaks)
Other symptoms:
Difficulty waking despite adequate sleep
Need caffeine to function
Energy crashes in afternoon
Second wind late evening
Difficulty handling stress
Salt cravings
Dizziness upon standing
What to do:
Saliva or urine cortisol testing (4-point throughout day) shows patterns blood tests miss
Stress management is essential: Meditation, Yoga, therapy, boundaries
Adaptogenic herbs (ashwagandha, rhodiola) – discuss with healthcare provider
Prioritize sleep (cortisol regulation happens during sleep)
Balance blood sugar (prevents cortisol spikes)
Reduce caffeine (not eliminate, but optimize timing and amount)
Reason #10: Depression
How common: 1 in 8 women will experience depression, risk increases during perimenopause/menopause
What’s happening: Depression isn’t just sadness—it’s a physiological condition affecting neurotransmitters, sleep, appetite, and energy. Fatigue is often the primary symptom, especially in women.
Why it’s missed: Many women don’t feel “sad,” just exhausted and unmotivated. They attribute it to physical causes and don’t recognize depression.
Other symptoms:
Loss of interest in activities you used to enjoy
Difficulty concentrating or making decisions
Changes in appetite or weight
Sleep disturbances (too much or too little)
Feelings of worthlessness or guilt
Physical aches and pains
Thoughts of death or suicide (seek immediate help)
What to do:
Honest assessment with healthcare provider or therapist
Depression screening (PHQ-9 questionnaire)
Therapy (CBT particularly effective)
Consider medication if appropriate (may improve energy within weeks)
Exercise (as effective as antidepressants for mild-moderate depression)
Social connection (isolation worsens depression)
Rule out medical causes first (thyroid, B12, etc.)
Important: Depression and physical causes often coexist. Treat both.
Reason #11: Chronic Dehydration
How common: Studies suggest 75% of Americans are chronically dehydrated
What’s happening: Even 2% dehydration significantly impairs physical and cognitive performance. Most people are walking around 5-10% dehydrated without realizing it.
Why it’s so common:
Thirst mechanism decreases with age
Caffeine and alcohol are diuretic
Busy schedules = forgetting to drink
Mistaking thirst for hunger
Other symptoms:
Dry mouth and lips
Dark yellow urine
Headaches
Dizziness
Constipation
Dry skin
Difficulty concentrating
What to do:
Aim for half your body weight in ounces daily (150 lb = 75 oz minimum)
More if exercising, in hot climates, or drinking caffeine
Start day with 16 oz water before coffee
Drink water with each meal
Set phone reminders every 2 hours
Eat water-rich foods (cucumbers, watermelon, lettuce)
Check urine color (pale yellow is goal)
The game-changer: Many people report dramatic energy improvement within days of adequate hydration. It’s the easiest fix with the fastest results.
Reason #12: Perimenopause/Menopause
How common: All women experience this, typically 45-55, but can start earlier
What’s happening: Fluctuating and declining estrogen and progesterone affect sleep quality, temperature regulation, mood, and metabolism. Night sweats disrupt sleep architecture even if you don’t fully wake.
The hormonal chaos: During perimenopause, hormones don’t just decline—they fluctuate wildly, creating unpredictable symptoms that vary day to day.
Other symptoms:
Hot flashes and night sweats
Irregular periods
Mood changes or irritability
Weight gain (especially abdominal)
Brain fog or memory issues
Decreased libido
Vaginal dryness
Joint pain
What to do:
Track symptoms and menstrual cycle patterns
Discuss hormone testing with doctor (though levels fluctuate, limiting usefulness)
Consider hormone replacement therapy (HRT) – newer research shows benefits often outweigh risks for many women
Lifestyle optimization: strength training, adequate protein, stress management, quality sleep
Dress in layers for temperature fluctuations
Keep bedroom cool (65-68°F optimal)
Reduce alcohol and spicy foods (trigger hot flashes)
The pharmacist’s perspective: HRT decisions are complex and individual. Work with a menopause-specialized provider who stays current on research. The blanket fear of HRT from early 2000s studies has been largely overturned by better research.
When Multiple Causes Overlap
Here’s the reality: It’s rarely just ONE thing.
The most exhausted women I work with typically have 3-5 overlapping issues:
Thyroid dysfunction + iron deficiency + poor sleep
Perimenopause + blood sugar issues + inflammation
Medication side effects + B12 deficiency + stress
This is why generic advice fails. You can’t “just eat better and exercise more” your way out of untreated hypothyroidism or severe B12 deficiency.
The Diagnostic Approach
Step 1: Comprehensive Testing
Work with your doctor to get:
Complete thyroid panel (TSH, Free T3, Free T4, antibodies)
Iron panel (ferritin, serum iron, TIBC, CBC)
Vitamin D (25-hydroxy)
Vitamin B12 and folate
Comprehensive metabolic panel
Hemoglobin A1c and fasting glucose
Inflammatory markers (CRP, ESR)
Hormone panel if appropriate
Don’t accept “everything is normal” if you feel terrible. Ask for actual numbers and optimal ranges.
Step 2: Medication Review
List every medication and supplement. Research or ask your pharmacist about fatigue as a side effect. Discuss alternatives with your doctor.
Step 3: Sleep Assessment
Track sleep for 2 weeks:
Hours in bed
Estimated actual sleep time
Sleep quality rating
Night wakings
Morning energy level
Daytime sleepiness
Consider sleep study if snoring, gasping, or poor sleep despite adequate hours.
Step 4: Lifestyle Audit
Honestly assess:
Protein intake (track for 3 days)
Hydration (track for 3 days)
Exercise (type, frequency, intensity)
Stress levels and coping mechanisms
Caffeine and alcohol consumption
Screen time before bed
The Nutrition and Lifestyle Foundation
While you’re investigating medical causes, optimize the basics:
Nutrition priorities:
25-30g protein at each meal
Half your body weight in ounces of water daily
Eliminate processed foods and added sugars
Focus on nutrient-dense whole foods
Balance carbohydrates with protein and fat
Consider 12-hour overnight fast for metabolic reset
Movement strategy:
Strength training 3-4x weekly (builds energy-producing muscle)
Daily walks (improves sleep, mood, energy)
Avoid excessive cardio (can worsen fatigue if overdone)
Listen to body—rest when needed
Sleep hygiene:
Consistent bed/wake times (even weekends)
7-9 hours minimum
Cool, dark, quiet room
No screens 1 hour before bed
Avoid caffeine after noon
No alcohol within 3 hours of bed
Stress management:
Daily practice: meditation, yoga, deep breathing, journaling
Set boundaries (learn to say no)
Social connection
Professional support if needed (therapy, Coaching)
The Bottom Line
Constant fatigue is NOT normal. It’s never “just stress” or “just aging.”
Your body is sending you a message. The question is whether you’ll listen and investigate, or dismiss it for another decade.
The most common scenario I see: Women suffer for 5-10 years before finally getting proper testing and discovering easily treatable causes like hypothyroidism or iron deficiency. Meanwhile, they’ve lost years of energy, productivity, and quality of life.
Don’t wait.
Start with comprehensive testing. Review your medications. Optimize your nutrition and lifestyle. Work with healthcare providers who take your concerns seriously.
You deserve to feel energized, capable, and alive—not just surviving on coffee and willpower.
Your fatigue is real. The causes are identifiable. The solutions exist.
Amy Wilson is a board-certified geriatric pharmacist (BCGP) and certified nutrition coach specializing in energy optimization and metabolic health for midlife women. For more evidence-based guidance on regaining your energy, visit amykwilson.com.
Exhausted despite “doing everything right”? Learn how strategic nutrition, medication optimization, and lifestyle modifications can restore your energy naturally.
Keywords: tired all the time, constant fatigue, why am I always tired, chronic fatigue causes, fatigue in women, always exhausted, medical reasons for tiredness, low energy causes, persistent fatigue, fatigue after 40
Originally Published on https://amykwilson.com/blog
