Table of ContentsView AllTable of ContentsLifestyle FactorsMedical CausesSleep DisordersMedications

Table of ContentsView All

View All

Table of Contents

Lifestyle Factors

Medical Causes

Sleep Disorders

Medications

The causes of constant tiredness and fatigue can stem from various factors that affect your energy levels throughout the day. These causes typically fall into four categories: lifestyle factors, medical conditions, sleep disorders, and mental health issues.

For example, excessive alcohol use or poor sleep hygiene can disrupt your routine and leave you feeling drained. Medical conditions like hypothyroidism, sleep disorders such as sleep apnea, or mental health issues like depression can also contribute to persistent fatigue.

Verywell / Cindy Chung

1:39Click Play to Learn What You Can Do to Feel Less Tired

1:39

Click Play to Learn What You Can Do to Feel Less Tired

Lifestyle Factors That Cause You to Feel Tired

Lifestyle can have a big impact on your daytime alertness and energy levels. Factors that you may want to discuss with a healthcare provider include:

Medical Conditions That Cause You to Feel Tired

Fatigue, general weakness, and feeling sleepy are symptoms associated with many medical conditions. These conditions affect your energy levels. Symptoms of daytime sleepiness may be related to the following underlying causes:

Recognizing a Heart AttackIn case of a heart attack, it’s important to get emergency medical help right away. You should call 9-1-1 if you or someone else has a sudden onset of any of these symptoms:Chest pain or pressure, which can also be felt in the upper abdomenPain that radiates to the jaw, neck, back, one or both arms, or stomachShortness of breathDizziness or faintingNausea or vomitingExtreme fatigue

Recognizing a Heart Attack

In case of a heart attack, it’s important to get emergency medical help right away. You should call 9-1-1 if you or someone else has a sudden onset of any of these symptoms:Chest pain or pressure, which can also be felt in the upper abdomenPain that radiates to the jaw, neck, back, one or both arms, or stomachShortness of breathDizziness or faintingNausea or vomitingExtreme fatigue

In case of a heart attack, it’s important to get emergency medical help right away. You should call 9-1-1 if you or someone else has a sudden onset of any of these symptoms:

Sleep Disorders That Cause You to Feel Tired

Various circadian rhythm disorders can leave youfeeling too sleepy during the day. The circadian rhythm is your body’s natural clock. It helps to coordinate your activities based on when it’s light and dark in your environment. If your internal timing is misaligned, you may find yourself with excessive daytime sleepiness.

Six common circadian rhythm disorders include:

Other sleep disorders that can result in constant tiredness or fatigue include:

Warning: Risk of Fatal ComplicationsSleep apnea puts a strain on your heart. It can lead to high blood pressure, cardiomyopathy (enlarged muscle tissue in the heart), heart failure, heart attack, and stroke. This makes proper diagnosis and treatment of sleep apnea especially important.

Warning: Risk of Fatal Complications

Sleep apnea puts a strain on your heart. It can lead to high blood pressure, cardiomyopathy (enlarged muscle tissue in the heart), heart failure, heart attack, and stroke. This makes proper diagnosis and treatment of sleep apnea especially important.

Medications That Cause Drowsiness

Drowsiness and fatigue are common side effects of medications. If you have daytime tiredness, your healthcare provider will likely look into what medications you’re taking. Drugs that can make you tired include:

Summary

Feeling tired and sleepy during the day can result from certain illnesses such as diabetes, heart disease, or an autoimmune disorder. Many cases of fatigue are also related to dehydration, specific sleep disorders, or chronic conditions such as chronic fatigue syndrome. If you are experiencing constant tiredness or fatigue and do not know why, don’t hesitate to see a healthcare provider for an evaluation.

34 Sources

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Sejbuk M, Mirończuk-Chodakowska I, Witkowska AM.Sleep quality: A narrative review on nutrition, stimulants, and physical activity as important factors.Nutrients. 2022;14(9):1912. doi:10.3390/nu14091912

Harvard Health Publishing.Fight fatigue with fluids.

National Institutes of Health, National Institute on Aging.Fatigue in older adults.

Hartescu I, Morgan K, Stevinson CD.Increased physical activity improves sleep and mood outcomes in inactive people with insomnia: A randomized controlled trial.J Sleep Res. 2015;24(5):526-534. doi:10.1111/jsr.12297

National Institutes of Health, U.S. National Library of Medicine: MedlinePlus.Are you getting too much exercise?

American Psychological Association.Stress and sleep.

Sin NL, Wen JH, Klaiber P, Buxton OM, Almeida DM.Sleep duration and affective reactivity to stressors and positive events in daily life.Health Psychol. 2020; doi:10.1037/hea0001033

University of Pennsylvania. Penn Medicine.What Is Anemia?

Zielinski MR, Systrom DM, Rose NR.Fatigue, sleep, and autoimmune and related disorders.Front Immunol. 2019;10:1827. doi:10.3389/fimmu.2019.01827

American Cancer Society.What is fatigue or weakness?

Sotzny F, Blanco J, Capelli E, et al.Myalgic encephalomyelitis/chronic fatigue syndrome - Evidence for an autoimmune disease.Autoimmun Rev. 2018;17(6):601-609. doi:10.1016/j.autrev.2018.01.009

Goërtz YMJ, Spruit MA, Van ’t Hul AJ, et al.Fatigue is highly prevalent in patients with COPD and correlates poorly with the degree of airflow limitation.Ther Adv Respir Dis. 2019;13:1753466619878128. doi:10.1177/1753466619878128

Corfield EC, Martin NG, Nyholt DR.Co-occurrence and symptomatology of fatigue and depression.Compr Psychiatry. 2016;71:1-10. doi:10.1016/j.comppsych.2016.08.004

Allen J, Romay-Tallon R, Brymer KJ, Caruncho HJ, Kalynchuk LE.Mitochondria and mood: Mitochondrial dysfunction as a key player in the manifestation of depression.Front Neurosci. 2018;12:386. doi:10.3389/fnins.2018.00386

Kalra S, Sahay R.Diabetes fatigue syndrome.Diabetes Ther. 2018;9(4):1421-1429. doi:10.1007/s13300-018-0453-x

Littlejohn G, Guymer E.Key milestones contributing to the understanding of the mechanisms underlying fibromyalgia.Biomedicines. 2020;8(7):223. doi:10.3390/biomedicines8070223

Wostyn P.COVID-19 and chronic fatigue syndrome: Is the worst yet to come?.Med Hypotheses. 2021;146:110469. doi:10.1016/j.mehy.2020.110469

Kerr JR.Epstein-Barr virus (EBV) reactivation and therapeutic inhibitors.J Clin Pathol. 2019;72(10):651-658. doi:10.1136/jclinpath-2019-205822

Pasta A, Formisano E, Calabrese F, et al.Food intolerances, food allergies, and IBS: Lights and shadows.Nutrients. 2024;16(2):265. doi:10.3390/nu16020265

National Institute of Diabetes and Digestive and Kidney Diseases.Anemia in chronic kidney disease.

Taylor-Swanson L, Wong AE, Pincus D, et al.The dynamics of stress and fatigue across menopause: Attractors, coupling, and resilience.Menopause. 2018;25(4):380-390. doi:10.1097/GME.0000000000001025

Bai G, Korfage IJ, Groen EH, Jaddoe VW, Mautner E, Raat H.Associations between Nausea, Vomiting, Fatigue and Health-Related Quality of Life of Women in Early Pregnancy: The Generation R Study. PLoS One. 2016 Nov 4;11(11):e0166133. doi: 10.1371/journal.pone.0166133

Harvard Medical School, Harvard Health Publishing.The lowdown on thyroid slowdown.

American Thyroid Association.Hyperthyroidism.

Harvard Medical School, Harvard Health Publishing.5 overlooked symptoms that may signal heart trouble.

National Institutes of Health, National Heart, Lung, and Blood Institute.Circadian rhythm disorders.

National Institutes of Health, National Heart, Lung, and Blood Institute.Insomnia.

de Oliveira MM, Conti C, Prado GF.Pharmacological treatment for Kleine-Levin syndrome.Cochrane Database Syst Rev. 2016;2016(5):CD006685. doi:10.1002/14651858.CD006685.pub4

National Organization for Rare Disorders.Narcolepsy.

National Institute of Neurological Disorders and Stroke.Restless legs syndrome.

Mount Sinai.Restless leg syndrome and related disorders.

Raheem OA, Orosco RK, Davidson TM, Lakin C.Clinical predictors of nocturia in the sleep apnea population.Urol Ann.2014;6(1):31-5. doi:10.4103/0974-7796.127019

Harvard Medical School, Harvard Health Publishing.What to do when medication makes you sleepy.

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