What causes a man to be tired all the time?

Last Updated: November 10, 2025 | Reading Time: 11 minutes

Understanding Chronic Male Fatigue

You wake up exhausted. Coffee gets you through the morning, but by afternoon you're counting down the hours until you can crash on the couch. Your mates joke that you're getting old, but you know something's off. This isn't normal tiredness from a late night or hard day at work. This is bone-deep fatigue that never seems to lift.

You're not imagining it, and you're definitely not alone. Clinical research reveals that persistent male fatigue typically stems from identifiable medical conditions rather than just "aging" or "being stressed." The challenge is that these causes often fly under the radar because their symptoms develop gradually and overlap with each other.

More concerning is how these conditions compound. A 2022 study published in The Aging Male examined 148 men over 70 with low testosterone and mobility issues. The research found that combining testosterone therapy with resistance training significantly reduced fatigue, but single interventions showed limited benefit. This pattern repeats across conditions: addressing one factor helps, but real improvement requires identifying and treating all contributing causes.

Low Testosterone: The Silent Energy Killer

Testosterone isn't just about libido and muscle mass. It plays a crucial role in energy production, motivation, and overall vitality. When levels drop, fatigue is often the earliest and most persistent symptom.

The Prevalence You Haven't Heard About

According to the American Journal of Medicine, testosterone deficiency affects approximately 30% of men aged 40-79 years. That's not a small number. A Canadian clinical practice guideline published in 2015 identifies sexual symptoms and fatigue as the earliest and most common presentations of testosterone deficiency.

Here's what makes it tricky: testosterone levels decline gradually, typically about 1% per year after age 30. This slow decline means you might not notice the change until you're significantly below optimal levels. You adapt to feeling tired, assuming it's just part of getting older.

Research-Backed Evidence

A 2022 clinical study compared 33 men with late-onset hypogonadism who had been on testosterone replacement therapy (TRT) for over a year against 30 newly diagnosed men. The results were striking: men on long-term TRT had significantly lower Fatigue Severity Scores compared to the newly diagnosed group. After adjusting for age and hypertension, TRT for over one year was associated with a 14.8-point decrease in fatigue scores.

A 2024 study from Denmark followed 148 men aged 70 and older with low testosterone and mobility problems for 52 weeks. Those receiving combined testosterone therapy and progressive resistance training reported significantly reduced fatigue and tiredness compared to control groups.

What low testosterone fatigue actually feels like:

• Exhaustion that doesn't improve with sleep
• Decreased motivation to tackle physical activities
• Loss of drive in both work and personal life
• Feeling "flat" emotionally
• Reduced recovery capacity after exercise

Getting Tested

The Canadian clinical guidelines emphasize that testosterone testing should involve two separate morning blood draws (between 7-10 AM when levels peak) showing levels below 300 ng/dL along with clinical symptoms. Don't accept a diagnosis based on symptoms alone, and don't dismiss the possibility if your testosterone is "technically normal" but on the lower end while you're experiencing classic symptoms.

Sleep Apnea: When "Getting Sleep" Isn't Enough

You're getting 7-8 hours of sleep every night but wake up feeling like you've been hit by a truck. Your partner mentions you snore loudly and sometimes seem to stop breathing. Welcome to obstructive sleep apnea (OSA), one of the most underdiagnosed causes of male fatigue.

The Numbers Are Staggering

A 2015 Swiss population-based study found that 49% of men aged 40-85 have moderate-to-severe OSA. The Wisconsin Sleep Cohort Study reported that 24% of men aged 30-60 have OSA, with the prevalence jumping to over 60% in middle-aged men who are overweight.

Here's the catch: about 1 billion people worldwide aged 30-65 are affected by OSA, yet the majority remain undiagnosed. Men are 2-3 times more likely than women to develop sleep apnea, independent of age, BMI, and other factors.

How Sleep Apnea Destroys Your Energy

During sleep, your airway repeatedly collapses, cutting off oxygen supply to your brain and body. Each episode (which can occur 30+ times per hour in severe cases) triggers a stress response that partially wakes you. You never reach deep, restorative sleep stages.

A 2009 study published in the journal Sleep surveyed nearly 300 adult OSA patients about specific symptoms. Fatigue, tiredness, and lack of energy improved robustly after positive airway pressure (PAP) treatment, to an extent appearing no less impressive than perceived improvements in sleepiness. The research demonstrated that 80% of patients reported fatigue symptoms even when they didn't report classic "sleepiness."

Signs you might have sleep apnea:

• Loud snoring that stops and starts throughout the night
• Gasping or choking sensations during sleep
• Morning headaches
• Excessive daytime fatigue despite "adequate" sleep
• Difficulty concentrating or memory problems
• Irritability or mood changes

The Workplace Safety Issue

Research published in the American Journal of Men's Health found that fatigued fathers have a 36% higher risk of workplace accidents and 26% higher risk of road accidents. If you work in construction, drive for a living, or operate heavy machinery, undiagnosed sleep apnea isn't just making you tired, it's dangerous.

Thyroid Dysfunction and Metabolic Slowdown

Your thyroid gland acts as your body's metabolic control center. When it underproduces hormones (hypothyroidism), everything slows down including your energy levels.

More Common Than You Think

According to the American Thyroid Association, more than 12 percent of Americans will develop a thyroid condition during their lifetime. Approximately 20 million Americans currently have some form of thyroid disease. While women are 5-8 times more likely to have thyroid problems than men, male thyroid disorders are often overlooked precisely because of this gender bias.

The National Institute of Diabetes and Digestive and Kidney Diseases reports that hypothyroidism affects around 5 percent of people aged 12 years or older in the United States, though most experience only mild symptoms that develop so gradually they're dismissed as normal aging.

Hypothyroid Fatigue Research

A 2023 study published in Healthcare examined patients with primary hypothyroidism before and after levothyroxine treatment. The research found that while thyroid hormone replacement significantly improved fatigue in most patients, approximately 26% continued experiencing fatigue despite normalized thyroid levels. This suggests multiple factors often contribute to the fatigue, not just the thyroid disorder itself.

Interestingly, a 2024 UK survey of 1,251 patients taking thyroid hormone replacement found that 89% still fulfilled criteria for abnormal fatigue despite treatment. This doesn't mean treatment doesn't work, it means many people have additional contributing factors that need addressing alongside thyroid management.

Hypothyroid myopathy (muscle weakness and pain associated with thyroid dysfunction) occurs in 30-80% of individuals with hypothyroidism. A 2024 review in the NCBI Bookshelf noted that proximal muscles like those in thighs, hips, shoulders, and neck are particularly affected, impacting activities such as stair climbing and lifting objects.

Hypothyroid symptoms beyond fatigue:

• Unexplained weight gain despite no diet changes
• Increased sensitivity to cold
• Constipation
• Dry skin and thinning hair
• Muscle aches and stiffness
• Slowed heart rate
• Depression or depressed mood

Iron Deficiency Without Anemia

Most blokes think iron deficiency only happens to women or causes obvious anemia. Wrong on both counts. Iron deficiency without anemia (IDNA) is a real condition that causes significant fatigue, and it's more common in active men than you'd expect.

The Hidden Prevalence

According to the American Academy of Family Physicians, the prevalence of iron deficiency anemia is 2% in adult men. However, iron deficiency without anemia is significantly more common. A study of 121 trained adults published in the Journal of the American Dietetic Association found that 4% of male athletes had iron deficiency without anemia, jumping to 29% in female athletes.

The World Health Organization recognizes iron deficiency anemia as the most common nutritional deficiency worldwide, affecting approximately 30% of the global population. In the United States specifically, the rate is lower but still significant, particularly in low-income populations and those with chronic health conditions.

Iron Deficiency and Fatigue: The Research

A 2017 meta-analysis published in the British Journal of Nutrition examined randomized controlled trials on iron supplementation in people with iron deficiency but no anemia. The results showed that improving iron status significantly decreased fatigue, even in the absence of anemia.

A 2018 systematic review in BMJ Open analyzed 18 trials and found that iron supplementation was associated with reduced subjective measures of fatigue in adults with IDNA. The review concluded that given the global prevalence of both iron deficiency and fatigue, patients and practitioners should consider iron-rich foods or supplementation to improve fatigue symptoms even without documented anemia.

In the UK, surveys found that fatigue prevalence was 22.5% in the community (ages 16-64) and 11.3% among primary-care patients (ages 18-45). Critically, about 60-80% of clinical fatigue cases had no identified physical cause, suggesting undiagnosed conditions like IDNA may be responsible.

Why Men Miss This Diagnosis

Iron deficiency in men typically results from:

• Occult gastrointestinal bleeding (often from regular NSAID use)
• Heavy athletic training depleting iron stores
• Poor dietary iron intake or absorption
• Chronic inflammatory conditions
• Regular blood donation

Because doctors rarely suspect iron issues in men, they often don't test for it unless anemia shows up on routine bloodwork. By that time, you've been iron-deficient and exhausted for months or years.

Depression and Anxiety: More Than Just Mood

Blokes often think depression is just feeling sad. In reality, persistent physical fatigue is one of the most common presenting symptoms of major depressive disorder (MDD) in men, sometimes appearing before any obvious mood changes.

The Fatigue-Depression Connection

A comprehensive review published in CNS Drugs found that fatigue occurs in over 90% of patients with major depressive disorder. More striking: in one study of 66 MDD patients, more than 90% had severe fatigue despite 80% already taking antidepressant medications.

Research published in the Journal of Psychosomatic Medicine found that up to one-third of MDD patients who achieve remission or response still continue to experience symptoms of fatigue. This residual fatigue is problematic because patients with persistent fatigue are more likely to relapse into depression, even while continuing treatment.

How Men Experience Depression Differently

A 2021 study in Frontiers in Psychiatry examined gender differences in depression symptoms. The research found that men exhibit more atypical signs including:

• Aggression and irritability rather than sadness
• Increased alcohol or substance use
• Physical fatigue and body aches
• Loss of interest in previously enjoyed activities
• Risk-taking behaviors

Women commonly report concurrent anxiety and mood symptoms, whereas men more often report physical complaints and may mask emotional symptoms. This contributes to underdiagnosis in males and explains why your doctor might miss depression if they're only asking about mood.

The Anxiety Component

Anxiety disorders frequently co-occur with chronic fatigue. A 2023 cross-sectional study from China found that 69.5% of chronic fatigue syndrome patients had anxiety and 79% had depression according to validated assessment scales. The study demonstrated significant correlation between fatigue severity and anxiety/depression levels.

Chronic worry and hypervigilance associated with anxiety are mentally and physically exhausting. Your body remains in a constant state of alert, burning through energy reserves even when you're sitting still.

Lifestyle Factors That Compound Fatigue

Medical conditions aside, several controllable factors dramatically impact energy levels. These often work synergistically with underlying health issues to create overwhelming fatigue.

Chronic Stress and Cortisol Dysregulation

Long-term stress disrupts your hypothalamic-pituitary-adrenal (HPA) axis, the system regulating stress hormones like cortisol. Early in chronic stress, cortisol levels spike. Eventually, your system becomes dysregulated, leading to inappropriate cortisol patterns that leave you wired at night but exhausted during the day.

For fathers specifically, research shows that "depleted dad syndrome" creates a dual pressure of being emotionally available while maintaining the breadwinner role. This constant mental load perpetuates the exhaustion cycle.

Poor Sleep Hygiene

Even without sleep apnea, inadequate sleep quality or quantity tanks your energy. Australian research found that new fathers lose an average of 109 minutes of sleep per night during the first year. Sleep deprivation impacts cognitive function, increases irritability, and substantially raises accident risk.

Nutritional Deficiencies Beyond Iron

Vitamin B12, vitamin D, and magnesium deficiencies all contribute to fatigue. These are particularly common in men over 50 due to decreased absorption and inadequate dietary intake. A 2023 study in the International Journal of Medical Sciences found that 28 days of B vitamin supplementation significantly improved physical performance and reduced fatigue in healthy adults.

Sedentary Lifestyle Paradox

When you're exhausted, the last thing you want to do is exercise. However, physical inactivity actually worsens fatigue over time. Regular movement improves mitochondrial function (your cells' energy powerhouses), enhances sleep quality, and reduces inflammation.

When Multiple Causes Overlap

Here's where chronic male fatigue gets complicated: these conditions don't exist in isolation. Low testosterone increases obesity risk, which worsens sleep apnea, which further suppresses testosterone. Depression reduces motivation to exercise and eat well, leading to nutritional deficiencies. Chronic stress disrupts sleep, which impairs thyroid function.

The Metabolic Syndrome Connection

Research published in The American Journal of Medicine found a strong bidirectional relationship between testosterone deficiency and metabolic syndrome (the cluster of conditions including high blood pressure, high blood sugar, excess body fat, and abnormal cholesterol). Each component of metabolic syndrome can independently cause fatigue, and together they create a self-reinforcing cycle.

Why a Comprehensive Approach Matters

The 2024 Danish study on testosterone and resistance training demonstrated that combined interventions work better than single approaches. Men receiving only testosterone or only exercise training showed modest improvements. Those receiving both experienced significantly better outcomes in physical performance and fatigue reduction.

This principle applies across all fatigue causes. Treating sleep apnea helps, but if you also have low testosterone and iron deficiency, you won't feel fully recovered until all three are addressed.

Supporting Energy Through Nutrition

While supplements can't replace medical treatment for underlying conditions, strategic nutritional support can help optimize energy production at the cellular level. Research-backed ingredients for energy metabolism include natural adaptogens like Siberian ginseng, B vitamins for metabolic function, and CoQ10 for mitochondrial energy production.

Father Fuel combines these evidence-based ingredients with L-theanine and natural caffeine to support sustained energy without the crashes common with synthetic stimulants. However, supplements work best when underlying medical conditions are properly diagnosed and treated.

Frequently Asked Questions

Key Takeaways

The Bottom Line

Being tired all the time isn't just part of being a bloke in your 30s, 40s, or beyond. It's your body telling you something's off. The research is clear: chronic male fatigue stems from identifiable, treatable conditions that are often missed because symptoms develop gradually and overlap.

Stop accepting exhaustion as normal. Stop pushing through with coffee and willpower. Book an appointment with your doctor and request comprehensive testing. Be specific about your symptoms, including how long you've been tired, what makes it better or worse, and any other changes you've noticed.

Most importantly, understand that addressing chronic fatigue often requires a multi-pronged approach. Fixing your sleep apnea helps, but if you also have low testosterone, you'll need both treated to feel truly energized. Managing depression matters, but if iron deficiency contributes, you need nutritional support too.

Your energy directly impacts every aspect of your life: work performance, relationships, physical health, and mental wellbeing. You deserve to feel strong, focused, and capable rather than dragging yourself through each day. The conditions causing your fatigue are real, they're common, and they're treatable.

Take the first step today.