Definition

By Mayo Clinic Staff

Fatigue is a common symptom. Almost everyone feels it during short-term illness. Fortunately, fatigue usually goes away when the illness is over.

But sometimes fatigue doesn't go away. It doesn't get better with rest. And the cause might be unclear.

Fatigue reduces energy, the ability to do things and the ability to focus. Ongoing fatigue affects quality of life and state of mind.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

We use the data you provide to deliver you the content you requested. To provide you with the most relevant and helpful information, we may combine your email and website data with other information we have about you. If you are a Mayo Clinic patient, we will only use your protected health information as outlined in our Notice of Privacy Practices. You may opt out of email communications at any time by clicking on the unsubscribe link in the email.

Feb. 11, 2023

See also

  1. 6 tips to manage rheumatoid arthritis symptoms
  2. Acetyl-L-carnitine: Can it relieve MS fatigue?
  3. Acromegaly
  4. Acute bronchitis: Is it contagious?
  5. Acute kidney injury
  6. Acute lymphocytic leukemia
  7. Acute myelogenous leukemia
  8. Acute sinusitis
  9. Acute sinusitis: Do over-the-counter treatments help?
  10. Addison's disease
  11. Adenocarcinoma: How this type of cancer affects prognosis
  12. Adjuvant therapy for cancer
  13. Adrenal fatigue: What causes it?
  14. Alcoholic hepatitis
  15. Ambien: Is dependence a concern?
  16. Amputation and diabetes
  17. Amyloidosis
  18. Anaphylaxis
  19. Anaphylaxis: First aid
  20. Anemia
  21. Angina
  22. Anorexia nervosa
  23. Anthrax
  24. Antidepressant withdrawal: Is there such a thing?
  25. Antidepressants and alcohol: What's the concern?
  26. Antidepressants and weight gain: What causes it?
  27. Antidepressants: Can they stop working?
  28. Antidepressants for children and teens
  29. Antidepressants: Side effects
  30. Antidepressants: Selecting one that's right for you
  31. Antidepressants: Which cause the fewest sexual side effects?
  32. Anxiety disorders
  33. Aortic calcification: An early sign of heart valve problems?
  34. Aortic valve regurgitation
  35. Aortic valve stenosis
  36. Aplastic anemia
  37. ARDS
  38. Arteriovenous fistula
  39. Artificial sweeteners: Any effect on blood sugar?
  40. Ascariasis
  41. Aspergillosis
  42. Atrial septal defect (ASD)
  43. Atrioventricular canal defect
  44. Atypical antidepressants
  45. Atypical cells: Are they cancer?
  46. Autoimmune hepatitis
  47. Automated external defibrillators: Do you need an AED?
  48. Biliary tract cancer: Should I get a second opinion?
  49. Biopsy procedures
  50. Bipolar disorder
  51. Bipolar disorder and alcoholism: Are they related?
  52. Bipolar disorder in children: Is it possible?
  53. Bipolar medications and weight gain
  54. Bipolar treatment: 1 versus 2
  55. Blastocystis hominis
  56. Blood Cancers and Disorders
  57. Blood clots during menstruation: A concern?
  58. Blood glucose meters
  59. Blood glucose monitors
  60. Blood sugar levels can fluctuate for many reasons
  61. Blood sugar testing: Why, when and how
  62. Blood tests for heart disease
  63. Mitral valve clip to treat mitral regurgitation: Bob's story
  64. Bone and joint problems associated with diabetes
  65. Bone cancer
  66. Bradycardia
  67. Mitral valve overview
  68. Explaining multiple sclerosis
  69. How kidneys work
  70. Jack Long — Live LONG - Beat STRONG to find a cure
  71. A leaky tricuspid valve
  72. Leaky valve cone procedure
  73. Video: Septal myectomy and apical myectomy
  74. Treating Pericarditis
  75. Bronchitis
  76. Brucellosis
  77. Brugada syndrome
  78. Burkitt lymphoma
  79. Caffeine: Does it affect blood sugar?
  80. Calcium supplements: A risk factor for heart attack?
  81. Can vitamins help prevent a heart attack?
  82. Cancer
  83. Cancer
  84. Cancer blood tests
  85. Myths about cancer causes
  86. Infographic: Cancer Clinical Trials Offer Many Benefits
  87. Cancer diagnosis: 11 tips for coping
  88. Cancer-related fatigue
  89. Cancer Managing Symptoms
  90. Cancer pain: Relief is possible
  91. Cancer risk: What the numbers mean
  92. Cancer surgery
  93. Cancer survival rate
  94. Cancer survivors: Care for your body after treatment
  95. Cancer survivors: Late effects of cancer treatment
  96. Cancer survivors: Managing your emotions after cancer treatment
  97. Cancer treatment myths
  98. Cardiac asthma: What causes it?
  99. Cardiomyopathy
  100. Castleman disease
  101. Celiac disease
  102. Chagas disease
  103. Chelation therapy for heart disease: Does it work?
  104. Chemo brain
  105. Chemotherapy side effects: A cause of heart disease?
  106. Cholangiocarcinoma (bile duct cancer)
  107. Cholera
  108. Chronic kidney disease
  109. Chronic kidney disease: Is a clinical trial right for me?
  110. Chronic lymphocytic leukemia
  111. Chronic myelogenous leukemia
  112. Chronic sinusitis
  113. Churg-Strauss syndrome
  114. Cirrhosis
  115. What is cirrhosis? A Mayo Clinic expert explains
  116. Cirrhosis FAQs
  117. Clinical depression: What does that mean?
  118. Coconut oil: Can it cure hypothyroidism?
  119. Cold and flu viruses: How long can they live outside the body?
  120. Cold or allergy: Which is it?
  121. Cold remedies
  122. Cold symptoms: Does drinking milk increase phlegm?
  123. Colon cancer
  124. Colon Cancer Family Registry
  125. Colon cancer screening: At what age can you stop?
  126. Colon cancer screening
  127. Colorectal Cancer
  128. Common cold
  129. Concussion
  130. Concussion in children
  131. Concussion Recovery
  132. Concussion Telemedicine
  133. Anxiety and diet
  134. Coronary artery spasm: Cause for concern?
  135. Craving and chewing ice: A sign of anemia?
  136. Crohn's Crisis
  137. Crohn's disease
  138. Crohn's disease and the gut microbiome
  139. What is Crohn's disease? A Mayo Clinic expert explains
  140. Crohn's or Colitis
  141. Curcumin: Can it slow cancer growth?
  142. Cushing syndrome
  143. Cyclothymia (cyclothymic disorder)
  144. Daily aspirin therapy
  145. Delusional parasitosis
  146. Demyelinating disease: What can you do about it?
  147. Depression and anxiety: Can I have both?
  148. Depression, anxiety and exercise
  149. What is depression? A Mayo Clinic expert explains.
  150. Depression in women: Understanding the gender gap
  151. Depression (major depressive disorder)
  152. Depression: Supporting a family member or friend
  153. Dermatomyositis
  154. Diabetes
  155. Diabetes and depression: Coping with the two conditions
  156. Diabetes and exercise: When to monitor your blood sugar
  157. Diabetes and heat
  158. What is type 1 diabetes? A Mayo Clinic expert explains
  159. 10 ways to avoid diabetes complications
  160. Diabetes diet: Should I avoid sweet fruits?
  161. Diabetes diet: Create your healthy-eating plan
  162. Diabetes drugs and weight loss
  163. Diabetes foods: Can I substitute honey for sugar?
  164. Diabetes and liver
  165. Diabetes management: How lifestyle, daily routine affect blood sugar
  166. Diabetes prevention: 5 tips for taking control
  167. Type 1 diabetes FAQs
  168. Diabetes symptoms
  169. Diabetes treatment: Can cinnamon lower blood sugar?
  170. Medications for type 2 diabetes
  171. Using insulin
  172. Diabetic coma
  173. Diabetic ketoacidosis
  174. Cancer-related diarrhea
  175. Diffuse midline glioma (DMG)
  176. Dilated cardiomyopathy
  177. Does stress make rheumatoid arthritis worse?
  178. Drinking after hepatitis C cure: Is it safe?
  179. Drummer Beats Heart Disease
  180. Dumping syndrome
  181. Early HIV symptoms: What are they?
  182. Ease rheumatoid arthritis pain when grocery shopping
  183. Eating during cancer treatment: Tips to make food tastier
  184. Eating right for chronic kidney disease
  185. Ebstein anomaly
  186. ED Drugs for Pulmonary Hypertension
  187. Emerging treatments for multiple sclerosis
  188. Encephalitis
  189. Endocarditis
  190. Endometriosis
  191. What is endometriosis? A Mayo Clinic expert explains
  192. Endometriosis FAQs
  193. Enlarged liver
  194. Enlarged spleen (splenomegaly)
  195. Esophageal Cancer
  196. Esophageal cancer
  197. Ewing sarcoma
  198. Exercise and multiple sclerosis
  199. Fasting diet: Can it improve my heart health?
  200. Fibromyalgia
  201. Flu masks
  202. Flu Shot Prevents Heart Attack
  203. Flu shots
  204. Flu shots and heart disease
  205. Flu: When to see a doctor?
  206. Flu vaccine: Safe for people with egg allergy?
  207. Follicular lymphoma
  208. Gaucher disease
  209. Generalized anxiety disorder
  210. Genetics and Cardiomyopathy
  211. GI Stents
  212. Giardia infection (giardiasis)
  213. Glomerulonephritis
  214. Glycemic index: A helpful tool for diabetes?
  215. Granulomatosis with polyangiitis
  216. Grass-fed beef
  217. Graves' disease
  218. H1N1 flu (swine flu)
  219. Hairy cell leukemia
  220. Hangovers
  221. Hashimoto's disease
  222. Healthy Heart for Life!
  223. Heart and Blood Health
  224. Heart arrhythmia
  225. Heart attack
  226. Heart attack prevention: Should I avoid secondhand smoke?
  227. Heart attack symptoms
  228. Heart Attack Timing
  229. Heart cancer: Is there such a thing?
  230. Heart disease
  231. Heart disease in women: Understand symptoms and risk factors
  232. Heart failure
  233. Heart failure and sex: Is it safe?
  234. Heart-healthy diet: 8 steps to prevent heart disease
  235. Heart Rhythm Conditions
  236. Heat exhaustion
  237. Heavy menstrual bleeding
  238. Heavy periods: Can folic acid help?
  239. Hemochromatosis
  240. Hemolytic uremic syndrome (HUS)
  241. Hemophilia
  242. Hepatitis A
  243. Hepatitis B
  244. Hepatitis C
  245. Hepatitis C: How common is sexual transmission?
  246. Hepatitis C: What happens in end-stage liver disease?
  247. Herbal treatment for anxiety: Is it effective?
  248. Hiatal hernia
  249. High-dose flu vaccines: How are they different from other flu vaccines?
  250. High-dose vitamin C: Can it kill cancer cells?
  251. Hilar cholangiocarcinoma
  252. Hirschsprung's disease
  253. HIV/AIDS
  254. Hodgkin lymphoma (Hodgkin disease)
  255. Hodgkin's vs. non-Hodgkin's lymphoma: What's the difference?
  256. Holiday Heart
  257. How do I reduce fatigue from rheumatoid arthritis?
  258. Humidifiers
  259. Huntington's disease
  260. Hypercalcemia
  261. Hyperglycemia in diabetes
  262. Hyperinsulinemia: Is it diabetes?
  263. Hyperparathyroidism
  264. Hyperthyroidism (overactive thyroid)
  265. Hypertrophic cardiomyopathy
  266. Hypertrophic Cardiomyopathy HCM
  267. Hyponatremia
  268. Hypoparathyroidism
  269. Hypopituitarism
  270. Hypothermia
  271. Hypothyroidism: Can calcium supplements interfere with treatment?
  272. Hypothyroidism diet
  273. Hypothyroidism and joint pain?
  274. Hypothyroidism: Should I take iodine supplements?
  275. Hypothyroidism symptoms: Can hypothyroidism cause eye problems?
  276. Hypothyroidism (underactive thyroid)
  277. Inflammatory bowel disease (IBD)
  278. Inflammatory bowel disease FAQs
  279. Influenza (flu)
  280. Insomnia
  281. Insomnia: How do I stay asleep?
  282. Insomnia treatment: Cognitive behavioral therapy instead of sleeping pills
  283. Insulin and weight gain
  284. Intervention: Help a loved one overcome addiction
  285. Iron deficiency anemia
  286. Is a clinical trial for biliary tract cancer right for me?
  287. Is depression a factor in rheumatoid arthritis?
  288. Is there a special diet for Crohn's disease?
  289. Jet lag disorder
  290. Kidney cancer
  291. Kidney Cancer
  292. Kidney Cancer
  293. What is kidney cancer? An expert explains
  294. Kidney cancer FAQs
  295. What is kidney disease? An expert explains
  296. Kidney disease FAQs
  297. Lack of sleep: Can it make you sick?
  298. Late-night eating: OK if you have diabetes?
  299. LADA
  300. Lead poisoning
  301. Legionnaires' disease
  302. Leukemia
  303. Liver cancer
  304. Liver Cancer
  305. What is liver cancer? An expert explains
  306. Liver cancer FAQs
  307. Liver cysts: A cause of stomach pain?
  308. Liver disease
  309. Liver Diseases
  310. Living better with Crohn's disease
  311. Living better with rheumatoid arthritis
  312. Living with biliary tract cancer
  313. Living with Lupus
  314. Long QT syndrome
  315. Low blood counts
  316. Low blood pressure (hypotension)
  317. Low blood sodium in older adults: A concern?
  318. Low-phosphorus diet: Helpful for kidney disease?
  319. Lupus
  320. Lyme disease
  321. Maintain your social life with Crohn's disease
  322. Male depression: Understanding the issues
  323. Male hypogonadism
  324. Mantle cell lymphoma
  325. MAOIs and diet: Is it necessary to restrict tyramine?
  326. Marijuana and depression
  327. Mayo Clinic Minute: Why getting vaccinated for the flu is doubly important this season
  328. Mayo Clinic Minute: Will there be a Lyme disease vaccine for humans?
  329. Measles Virus as a Cancer Fighter
  330. Membranous nephropathy
  331. Mental health: Overcoming the stigma of mental illness
  332. Mental health providers: Tips on finding one
  333. Mental illness
  334. Menus for heart-healthy eating
  335. Mitral valve prolapse
  336. Mitral valve regurgitation
  337. Mitral valve stenosis
  338. Mixed connective tissue disease
  339. Monoamine oxidase inhibitors (MAOIs)
  340. Monoclonal antibody drugs
  341. Mononucleosis
  342. Mononucleosis: Can it recur?
  343. Mononucleosis and Epstein-Barr: What's the connection?
  344. Mort Crim and Cancer
  345. Mouth sores caused by cancer treatment: How to cope
  346. MRI: Is gadolinium safe for people with kidney problems?
  347. Multiple myeloma
  348. Infographic: Multiple Myeloma
  349. Multiple sclerosis
  350. Infographic: Multiple Sclerosis
  351. Multiple sclerosis: Can it cause seizures?
  352. What is multiple sclerosis? An expert explains
  353. Multiple sclerosis FAQs
  354. Multisystem inflammatory syndrome in children (MIS-C)
  355. Mumps
  356. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
  357. Myelodysplastic syndromes
  358. Myelofibrosis
  359. Myelofibrosis
  360. Myocarditis
  361. Natural remedies for depression: Are they effective?
  362. Nervous breakdown: What does it mean?
  363. Neti pot: Can it clear my nose?
  364. New Hep C Treatment
  365. What is ulcerative colitis? A Mayo Clinic expert explains
  366. No appetite? How to get nutrition during cancer treatment
  367. Nonalcoholic fatty liver disease
  368. Non-Hodgkin lymphoma
  369. NSAIDs: Do they increase my risk of heart attack and stroke?
  370. Nuts and your heart: Eating nuts for heart health
  371. He's the bravest kid I've ever seen
  372. Omega-3 in fish
  373. Omega-6 fatty acids
  374. Living with an ostomy
  375. Pacemaker and ICDs
  376. Pain and depression: Is there a link?
  377. Palliative care for biliary tract cancer
  378. Parvovirus infection
  379. Pectus excavatum
  380. Pectus excavatum
  381. Pelvic inflammatory disease (PID)
  382. Pericarditis
  383. Peritonitis
  384. Persistent depressive disorder
  385. Persistent post-concussive symptoms (Post-concussion syndrome)
  386. Plague
  387. Plugged ears: What is the remedy?
  388. Pneumonia
  389. Pneumonitis
  390. Polio
  391. Polycythemia vera
  392. Polymyalgia rheumatica
  393. Polymyositis
  394. Polypill: Does it treat heart disease?
  395. Post COVID syndrome
  396. Postpartum depression
  397. Post-polio syndrome
  398. Precision medicine: A new way to treat biliary cancers
  399. Prediabetes
  400. Premenstrual dysphoric disorder
  401. Premenstrual syndrome (PMS)
  402. Prescription sleeping pills: What's right for you?
  403. Primary biliary cholangitis
  404. Primary sclerosing cholangitis
  405. Protect your joints while housecleaning
  406. Pulmonary atresia
  407. Pulmonary atresia with intact ventricular septum
  408. Pulmonary edema
  409. Pulmonary fibrosis
  410. Pulmonary hypertension
  411. Pulmonary valve stenosis
  412. Reactive hypoglycemia: What can I do?
  413. Rectal cancer
  414. Recurring strep throat: When is tonsillectomy useful?
  415. Red wine, antioxidants and resveratrol
  416. Renal diet for vegetarians
  417. Rethinking Rheumatoid Arthritis
  418. Rhabdomyolysis
  419. Rheumatic fever
  420. Rheumatoid arthritis
  421. Rheumatoid arthritis
  422. Rheumatoid arthritis: Does pregnancy affect symptoms?
  423. List Title Rheumatoid arthritis and exercise
  424. Rheumatoid arthritis: Can it affect the eyes?
  425. Rheumatoid arthritis: Can it affect the lungs?
  426. Robotic heart surgery treats mitral regurgitation: Ed's story
  427. Roseola
  428. Salt craving: A symptom of Addison's disease?
  429. Sarcoidosis
  430. Selective serotonin reuptake inhibitors (SSRIs)
  431. Self-care for the flu
  432. Self-Image During Cancer
  433. Serotonin and norepinephrine reuptake inhibitors (SNRIs)
  434. Sheehan's syndrome
  435. Shingles
  436. Shingles and alcohol
  437. Shingles vaccine: Can I transmit the vaccine virus to others?
  438. Shingles vaccine: Should I get it?
  439. Sick sinus syndrome
  440. Silent heart attack
  441. Sinus headaches
  442. Sinus infection and toothache: Any connection?
  443. Sjogren's syndrome
  444. Small cell, large cell cancer: What this means
  445. Small vessel disease
  446. Smallpox
  447. Somatic symptom disorder
  448. Soy: Does it worsen hypothyroidism?
  449. Staying active with Crohn's disease
  450. Stomach cancer
  451. What is stomach cancer? A Mayo Clinic expert explains
  452. Stomach cancer FAQs
  453. Heart disease prevention
  454. Strep throat
  455. Strep throat in young children: A common diagnosis?
  456. Sudden cardiac arrest
  457. Sudden death in young people: Heart problems often blamed
  458. Sun damage
  459. Sunburn
  460. Takayasu's arteritis
  461. Teen depression
  462. Test anxiety: Can it be treated?
  463. Thalassemia
  464. The dawn phenomenon: What can you do?
  465. Thyroid disease: Can it affect a person's mood?
  466. Thyroid peroxidase antibody test: What is it?
  467. Tips for easing stress when you have Crohn's disease
  468. Tips to make your mornings easier
  469. Tonic-clonic (grand mal) seizure
  470. Toxic hepatitis
  471. Toxoplasmosis
  472. Transplants
  473. Treatment of parathyroid disease at Mayo Clinic
  474. Treatment options for biliary tract cancer
  475. Treatment-resistant depression
  476. Tricuspid atresia
  477. Tricuspid valve regurgitation
  478. Tricyclic antidepressants
  479. Tuberculosis
  480. Tumor vs. cyst: What's the difference?
  481. Type 1 diabetes
  482. Type 1 diabetes in children
  483. Type 2 diabetes
  484. Type 2 diabetes in children
  485. Typhoid fever
  486. Ulcerative colitis
  487. Ulcerative colitis flare-ups: 5 tips to manage them
  488. Understanding complement 3 glomerulopathy (C3G)
  489. Valerian: A safe and effective herbal sleep aid?
  490. Valley fever
  491. Vasculitis
  492. Vegetarian diet: Can it help me control my diabetes?
  493. Ventricular septal defect (VSD)
  494. Vicks VapoRub: An effective nasal decongestant?
  495. Video: Heart and circulatory system
  496. How cancer spreads
  497. Mitral valve regurgitation
  498. PICC line placement
  499. Grateful patient talks about his Mayo Clinic experience
  500. Viral hemorrhagic fevers
  501. Vitamin B-12 and depression
  502. Vitamin D and MS: Any connection?
  503. Vitamin deficiency anemia
  504. Vitamins for MS: Do supplements make a difference?
  505. Von Willebrand disease
  506. Walking pneumonia
  507. Warm-mist versus cool-mist humidifier: Which is better for a cold?
  508. Watch an interview with Fernando C Fervenza MD PhD
  509. West Nile virus
  510. Heart failure action plan
  511. What is biliary tract cancer?
  512. What's the difference between H1N1 flu and influenza A?
  513. When cancer returns: How to cope with cancer recurrence
  514. Where can I learn more about living with Crohn's disease?
  515. Whiplash
  516. Whipple's disease
  517. Whooping cough
  518. Whooping cough
  519. Why isn't there a hepatitis C vaccine?
  520. Wilson's disease
  521. Effectively managing chronic kidney disease
  522. Do zinc supplements shorten colds?