Check the markers behind low energy in men
Total testosterone, ferritin, TSH, vitamin D, and HbA1c, measured in a single draw
- CLIA-certified labs
- HIPAA compliant
- Personalized health protocol
Why men lose energy: the most common causes
Low energy in men most often comes from sleep problems, low mood, or stress, or from a medical cause a blood test can measure. Those measurable causes include low testosterone, iron deficiency, an underactive thyroid, and high blood sugar.
Fatigue means a lack of energy and motivation, unlike drowsiness, which is the need to sleep. In national survey data from 2010 to 2011, about 1 in 10 US adult men (10.1%) often felt very tired or exhausted. For some, the reason shows up in a routine blood sample.
Medical causes of low energy in men
Most medical causes of low energy in men, whether hormone, nutrient, thyroid, or blood sugar, show up on a standard blood draw through a specific marker.
| Cause | How it drains energy | Blood marker that checks it |
|---|---|---|
| Low testosterone | Lower levels track with fatigue and less capacity for vigorous activity | Total testosterone, free testosterone, and sex hormone-binding globulin (SHBG) |
| Iron deficiency | Low iron stores can cause fatigue, trouble concentrating, and exercise intolerance, even before anemia | Ferritin and hemoglobin |
| Low vitamin B12 | Low levels can cause fatigue, lack of energy, and lightheadedness | Vitamin B12 |
| Low vitamin D | Correcting a true deficiency may ease fatigue, based on 1 trial | 25-hydroxyvitamin D |
| Underactive thyroid | Without enough thyroid hormone, many body functions slow down | Thyroid-stimulating hormone (TSH) |
| High blood sugar | Fatigue is a common diabetes symptom, and type 2 can develop slowly with few signs | Hemoglobin A1c (HbA1c) and fasting glucose |
Low testosterone grows more common with age as levels gradually decline, reaching about 20% of men over 60 and 30% of men over 70 in one long-running study. Fatigue alone points to low testosterone less reliably than low desire, erectile problems, or fewer morning erections. Much of what drains a man's energy never appears on a lab report.
Sleep, mood, and lifestyle drains on men's energy
Sleep, mood, and daily life drain men's energy in ways no routine blood panel shows.
- Obstructive sleep apnea causes breathing pauses, loud snoring, and gasping at night, plus daytime fatigue, and is more common and often more serious in men.
- Nighttime urination, two or more trips a night, is linked to poorer sleep and daytime sleepiness in men, often from an enlarged prostate, the most common prostate problem past 50.
- Depression in men can show up as anger, aggression, substance use, or risk taking, which standard symptom checklists can miss.
- Medications such as sedatives, antihistamines, blood pressure medicines, antidepressants, and steroids can all cause fatigue.
When tiredness lingers past these, careful blood work is the next step.
Blood tests that explain low energy in men
Blood tests explain low energy in men best when each marker is timed well and read against symptoms. A low fasting morning total testosterone is repeated to confirm it, with free testosterone and SHBG added near the lower limit.
A reference range describes where most people fall, so an in-range result can still leave tiredness unexplained. Ferritin can drop while hemoglobin stays in range, so a blood count alone misses low iron stores without anemia. A low-normal vitamin B12 may need a follow-up methylmalonic acid test (a second B12 marker) to confirm a deficiency.
Vitamin D is one marker a clinician may check for persistent fatigue, though routine testing is not advised without a specific reason. Daily habits stay within a man's control.
How to restore energy as a man
Regular sleep, exercise, and calmer evenings can help restore energy in men.
- Keep a regular schedule with seven or more hours of sleep a night.
- Pair aerobic activity with strength training on two or more days a week, a habit linked to more energy and less fatigue.
- Stop substantial caffeine at least 6 hours before bed.
- Keep alcohol clear of bedtime, since a drink disrupts the second half of the night.
- Drink fewer liquids in the evening if waking to urinate breaks your sleep.
Energy that stays low with these habits in place is a reason to see a doctor.
Get 100+ biomarkers tested in-lab or at home
One blood draw a year. A full picture of your health, explained in plain language.
Get 100+ biomarkers tested in-lab or at home
One blood draw a year. A full picture of your health, explained in plain language.
When low energy in men needs a doctor
Low energy in men needs a doctor's visit when fatigue does not improve with enough sleep, good nutrition, and lower stress. The same goes for tiredness with fever, unintentional weight loss, or regular sweats.
Seek care right away for fatigue with confusion or dizziness; blurred vision; little or no urine; or recent swelling and weight gain. Anyone with thoughts of self-harm, or a sense of having no energy to live, can call or text 988 for free, confidential help.
For low energy with a measurable cause, seeing energy markers together is a useful start.
Understand men's energy markers with Superpower
When one in-range result has not explained low energy, a comprehensive blood test with a wider set of markers is a sensible next step. A Superpower membership includes 100+ biomarkers in a single draw, among them total testosterone, SHBG, ferritin, hemoglobin, TSH, vitamin D, hemoglobin A1c, and glucose. Several medical causes of low energy in men show up in these markers. As a home for health, Superpower measures them and helps you improve them with a personalized protocol, plus AI and care team support.
It's time to get answers from your own data. Start your Superpower membership and get your baseline in one draw.
References
- MedlinePlus. Fatigue. National Library of Medicine. Reviewed May 19, 2025. Accessed October 17, 2026.
- Maisel P, Baum E, Donner-Banzhoff N. Fatigue as the chief complaint: epidemiology, causes, diagnosis, and treatment. *Dtsch Arztebl Int*. 2021;118(33-34):566-576. https://doi.org/10.3238/arztebl.m2021.0192
- Wu FC, Tajar A, Beynon JM, et al. Identification of late-onset hypogonadism in middle-aged and elderly men. *N Engl J Med*. 2010;363(2):123-135. https://doi.org/10.1056/NEJMoa0911101
- Centers for Disease Control and Prevention. QuickStats: percentage of adults who often felt very tired or exhausted in the past 3 months, by sex and age group — National Health Interview Survey, United States, 2010–2011. *MMWR Morb Mortal Wkly Rep*. 2013;62(14):275.
- Auerbach M, DeLoughery TG, Tirnauer JS. Iron deficiency in adults: a review. *JAMA*. 2025;333(20):1813-1823. https://doi.org/10.1001/jama.2025.0452
- MedlinePlus. Vitamin B12 deficiency anemia. National Library of Medicine. Reviewed January 29, 2026. Accessed October 17, 2026.
- Nowak A, Boesch L, Andres E, et al. Effect of vitamin D3 on self-perceived fatigue: a double-blind randomized placebo-controlled trial. *Medicine (Baltimore)*. 2016;95(52):e5353. https://doi.org/10.1097/MD.0000000000005353
- National Institute of Diabetes and Digestive and Kidney Diseases. Hypothyroidism (underactive thyroid). National Institutes of Health. Reviewed March 2021. Accessed October 17, 2026.
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & causes of diabetes. National Institutes of Health. Reviewed October 2024. Accessed October 17, 2026.
- Harman SM, Metter EJ, Tobin JD, Pearson J, Blackman MR. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. *J Clin Endocrinol Metab*. 2001;86(2):724-731. https://doi.org/10.1210/jcem.86.2.7219
- National Heart, Lung, and Blood Institute. Sleep apnea: symptoms. National Institutes of Health. Updated January 9, 2025. Accessed October 17, 2026.
- National Heart, Lung, and Blood Institute. Sleep apnea: causes and risk factors. National Institutes of Health. Updated January 9, 2025. Accessed October 17, 2026.
- Martin SA, Appleton SL, Adams RJ, et al. Nocturia, other lower urinary tract symptoms and sleep dysfunction in a community-dwelling cohort of men. *Urology*. 2016;97:219-226. https://doi.org/10.1016/j.urology.2016.06.022
- National Institute of Diabetes and Digestive and Kidney Diseases. Enlarged prostate (benign prostatic hyperplasia). National Institutes of Health. Reviewed June 2024. Accessed October 17, 2026.
- Martin LA, Neighbors HW, Griffith DM. The experience of symptoms of depression in men vs women: analysis of the National Comorbidity Survey Replication. *JAMA Psychiatry*. 2013;70(10):1100-1106. https://doi.org/10.1001/jamapsychiatry.2013.1985
- Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. *J Clin Endocrinol Metab*. 2018;103(5):1715-1744. https://doi.org/10.1210/jc.2018-00229
- Langan RC, Goodbred AJ. Vitamin B12 deficiency: recognition and management. *Am Fam Physician*. 2017;96(6):384-389.
- Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the prevention of disease: an Endocrine Society clinical practice guideline. *J Clin Endocrinol Metab*. 2024;109(8):1907-1947. https://doi.org/10.1210/clinem/dgae290
- Watson NF, Badr MS, Belenky G, et al. Recommended amount of sleep for a healthy adult: a joint consensus statement of the American Academy of Sleep Medicine and Sleep Research Society. *Sleep*. 2015;38(6):843-844. https://doi.org/10.5665/sleep.4716
- Piercy KL, Troiano RP, Ballard RM, et al. The Physical Activity Guidelines for Americans. *JAMA*. 2018;320(19):2020-2028. https://doi.org/10.1001/jama.2018.14854
- Puetz TW, O'Connor PJ, Dishman RK. Effects of chronic exercise on feelings of energy and fatigue: a quantitative synthesis. *Psychol Bull*. 2006;132(6):866-876. https://doi.org/10.1037/0033-2909.132.6.866
- Drake C, Roehrs T, Shambroom J, Roth T. Caffeine effects on sleep taken 0, 3, or 6 hours before going to bed. *J Clin Sleep Med*. 2013;9(11):1195-1200. https://doi.org/10.5664/jcsm.3170
- Ebrahim IO, Shapiro CM, Williams AJ, Fenwick PB. Alcohol and sleep I: effects on normal sleep. *Alcohol Clin Exp Res*. 2013;37(4):539-549. https://doi.org/10.1111/acer.12006
- Substance Abuse and Mental Health Services Administration. 988 Suicide & Crisis Lifeline. US Department of Health and Human Services. Updated September 26, 2025. Accessed October 17, 2026.
Heart & Vascular Health
Metabolic Health
Energy
Liver Health
Kidney
Sex Hormones
Thyroid Health
Nutrients
Immune System
Inflammation