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. Early-onset colon cancer
  183. Ease rheumatoid arthritis pain when grocery shopping
  184. Eating during cancer treatment: Tips to make food tastier
  185. Eating right for chronic kidney disease
  186. Ebstein anomaly
  187. ED Drugs for Pulmonary Hypertension
  188. Emerging treatments for multiple sclerosis
  189. Encephalitis
  190. Endocarditis
  191. Endometriosis
  192. What is endometriosis? A Mayo Clinic expert explains
  193. Endometriosis FAQs
  194. Enlarged liver
  195. Enlarged spleen (splenomegaly)
  196. Esophageal Cancer
  197. Esophageal cancer
  198. Ewing sarcoma
  199. Exercise and multiple sclerosis
  200. Fasting diet: Can it improve my heart health?
  201. Fibromyalgia
  202. Flu masks
  203. Flu Shot Prevents Heart Attack
  204. Flu shots
  205. Flu shots and heart disease
  206. Flu: When to see a doctor?
  207. Flu vaccine: Safe for people with egg allergy?
  208. Follicular lymphoma
  209. Gaucher disease
  210. Generalized anxiety disorder
  211. Genetics and Cardiomyopathy
  212. GI Stents
  213. Giardia infection (giardiasis)
  214. Glomerulonephritis
  215. Glycemic index: A helpful tool for diabetes?
  216. Granulomatosis with polyangiitis
  217. Grass-fed beef
  218. Graves' disease
  219. H1N1 flu (swine flu)
  220. Hairy cell leukemia
  221. Hangovers
  222. Hashimoto's disease
  223. Healthy Heart for Life!
  224. Heart and Blood Health
  225. Heart arrhythmia
  226. Heart attack
  227. Heart attack prevention: Should I avoid secondhand smoke?
  228. Heart attack symptoms
  229. Heart Attack Timing
  230. Heart cancer: Is there such a thing?
  231. Heart disease
  232. Heart disease in women: Understand symptoms and risk factors
  233. Heart failure
  234. Heart failure and sex: Is it safe?
  235. Heart-healthy diet: 8 steps to prevent heart disease
  236. Heart Rhythm Conditions
  237. Heat exhaustion
  238. Heavy menstrual bleeding
  239. Heavy periods: Can folic acid help?
  240. Hemochromatosis
  241. Hemolytic uremic syndrome (HUS)
  242. Hemophilia
  243. Hepatitis A
  244. Hepatitis B
  245. Hepatitis C
  246. Hepatitis C: How common is sexual transmission?
  247. Hepatitis C: What happens in end-stage liver disease?
  248. Herbal treatment for anxiety: Is it effective?
  249. Hiatal hernia
  250. High-dose flu vaccines: How are they different from other flu vaccines?
  251. High-dose vitamin C: Can it kill cancer cells?
  252. Hilar cholangiocarcinoma
  253. Hirschsprung's disease
  254. HIV/AIDS
  255. Hodgkin lymphoma (Hodgkin disease)
  256. Hodgkin's vs. non-Hodgkin's lymphoma: What's the difference?
  257. Holiday Heart
  258. How do I reduce fatigue from rheumatoid arthritis?
  259. Humidifiers
  260. Huntington's disease
  261. Hypercalcemia
  262. Hyperglycemia in diabetes
  263. Hyperinsulinemia: Is it diabetes?
  264. Hyperparathyroidism
  265. Hyperthyroidism (overactive thyroid)
  266. Hypertrophic cardiomyopathy
  267. Hypertrophic Cardiomyopathy HCM
  268. Hyponatremia
  269. Hypoparathyroidism
  270. Hypopituitarism
  271. Hypothermia
  272. Hypothyroidism: Can calcium supplements interfere with treatment?
  273. Hypothyroidism diet
  274. Hypothyroidism and joint pain?
  275. Hypothyroidism: Should I take iodine supplements?
  276. Hypothyroidism symptoms: Can hypothyroidism cause eye problems?
  277. Hypothyroidism (underactive thyroid)
  278. Inflammatory bowel disease (IBD)
  279. Inflammatory bowel disease FAQs
  280. Influenza (flu)
  281. Insomnia
  282. Insomnia: How do I stay asleep?
  283. Insomnia treatment: Cognitive behavioral therapy instead of sleeping pills
  284. Insulin and weight gain
  285. Intervention: Help a loved one overcome addiction
  286. Iron deficiency anemia
  287. Is a clinical trial for biliary tract cancer right for me?
  288. Is depression a factor in rheumatoid arthritis?
  289. Is there a special diet for Crohn's disease?
  290. Jet lag disorder
  291. Kidney cancer
  292. Kidney Cancer
  293. Kidney Cancer
  294. What is kidney cancer? An expert explains
  295. Kidney cancer FAQs
  296. What is kidney disease? An expert explains
  297. Kidney disease FAQs
  298. Lack of sleep: Can it make you sick?
  299. Late-night eating: OK if you have diabetes?
  300. LADA
  301. Lead poisoning
  302. Legionnaires' disease
  303. Leukemia
  304. Liver cancer
  305. Liver Cancer
  306. What is liver cancer? An expert explains
  307. Liver cancer FAQs
  308. Liver cysts: A cause of stomach pain?
  309. Liver disease
  310. Liver Diseases
  311. Living better with Crohn's disease
  312. Living better with rheumatoid arthritis
  313. Living with biliary tract cancer
  314. Living with Lupus
  315. Long QT syndrome
  316. Low blood counts
  317. Low blood pressure (hypotension)
  318. Low blood sodium in older adults: A concern?
  319. Low-phosphorus diet: Helpful for kidney disease?
  320. Lupus
  321. Lyme disease
  322. Macrocytosis: What causes it?
  323. Maintain your social life with Crohn's disease
  324. Male depression: Understanding the issues
  325. Male hypogonadism
  326. Mantle cell lymphoma
  327. MAOIs and diet: Is it necessary to restrict tyramine?
  328. Marijuana and depression
  329. Mayo Clinic Minute: Why getting vaccinated for the flu is doubly important this season
  330. Mayo Clinic Minute: Will there be a Lyme disease vaccine for humans?
  331. Measles Virus as a Cancer Fighter
  332. Membranous nephropathy
  333. Mental health: Overcoming the stigma of mental illness
  334. Mental health providers: Tips on finding one
  335. Mental illness
  336. Menus for heart-healthy eating
  337. Mitral valve prolapse
  338. Mitral valve regurgitation
  339. Mitral valve stenosis
  340. Mixed connective tissue disease
  341. Monoamine oxidase inhibitors (MAOIs)
  342. Monoclonal antibody drugs
  343. Mononucleosis
  344. Mononucleosis: Can it recur?
  345. Mononucleosis and Epstein-Barr: What's the connection?
  346. Mort Crim and Cancer
  347. Mouth sores caused by cancer treatment: How to cope
  348. MRI: Is gadolinium safe for people with kidney problems?
  349. Mucus in stool: A concern?
  350. Multiple myeloma
  351. Infographic: Multiple Myeloma
  352. Multiple sclerosis
  353. Infographic: Multiple Sclerosis
  354. Multiple sclerosis: Can it cause seizures?
  355. What is multiple sclerosis? An expert explains
  356. Multiple sclerosis FAQs
  357. Multisystem inflammatory syndrome in children (MIS-C)
  358. Mumps
  359. Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
  360. Myelodysplastic syndromes
  361. Myelofibrosis
  362. Myelofibrosis
  363. Myocarditis
  364. Natural remedies for depression: Are they effective?
  365. Nervous breakdown: What does it mean?
  366. Neti pot: Can it clear my nose?
  367. New Hep C Treatment
  368. What is ulcerative colitis? A Mayo Clinic expert explains
  369. No appetite? How to get nutrition during cancer treatment
  370. Nonalcoholic fatty liver disease
  371. Non-Hodgkin lymphoma
  372. NSAIDs: Do they increase my risk of heart attack and stroke?
  373. Nuts and your heart: Eating nuts for heart health
  374. He's the bravest kid I've ever seen
  375. Omega-3 in fish
  376. Omega-6 fatty acids
  377. Living with an ostomy
  378. Pacemaker and ICDs
  379. Pain and depression: Is there a link?
  380. Palliative care for biliary tract cancer
  381. Parvovirus infection
  382. Pectus excavatum
  383. Pectus excavatum
  384. Pelvic inflammatory disease (PID)
  385. Pericarditis
  386. Peritoneal carcinomatosis
  387. Peritonitis
  388. Persistent depressive disorder
  389. Persistent post-concussive symptoms (Post-concussion syndrome)
  390. Petroleum jelly: Safe for a dry nose?
  391. Plague
  392. Plugged ears: What is the remedy?
  393. Pneumonia
  394. Pneumonitis
  395. Polio
  396. Polycythemia vera
  397. Polymyalgia rheumatica
  398. Polymyositis
  399. Polypill: Does it treat heart disease?
  400. Post COVID syndrome
  401. Postpartum depression
  402. Post-polio syndrome
  403. Precision medicine: A new way to treat biliary cancers
  404. Prediabetes
  405. Prednisone withdrawal: Why taper down slowly?
  406. Premenstrual dysphoric disorder
  407. Premenstrual syndrome (PMS)
  408. Prescription sleeping pills: What's right for you?
  409. Primary biliary cholangitis
  410. Primary sclerosing cholangitis
  411. Protect your joints while housecleaning
  412. Pulmonary atresia
  413. Pulmonary atresia with intact ventricular septum
  414. Pulmonary edema
  415. Pulmonary fibrosis
  416. Pulmonary hypertension
  417. Pulmonary valve stenosis
  418. Reactive hypoglycemia: What can I do?
  419. Rectal cancer
  420. Recurring strep throat: When is tonsillectomy useful?
  421. Red wine, antioxidants and resveratrol
  422. Renal diet for vegetarians
  423. Rethinking Rheumatoid Arthritis
  424. Rhabdomyolysis
  425. Rheumatic fever
  426. Rheumatoid arthritis
  427. Rheumatoid arthritis
  428. Rheumatoid arthritis: Does pregnancy affect symptoms?
  429. List Title Rheumatoid arthritis and exercise
  430. Rheumatoid arthritis: Can it affect the eyes?
  431. Rheumatoid arthritis: Can it affect the lungs?
  432. Ricin poisoning
  433. Robotic heart surgery treats mitral regurgitation: Ed's story
  434. Roseola
  435. Salt craving: A symptom of Addison's disease?
  436. Sarcoidosis
  437. Selective serotonin reuptake inhibitors (SSRIs)
  438. Self-care for the flu
  439. Self-Image During Cancer
  440. Serotonin and norepinephrine reuptake inhibitors (SNRIs)
  441. Sheehan's syndrome
  442. Shingles
  443. Shingles and alcohol
  444. Shingles vaccine: Can I transmit the vaccine virus to others?
  445. Shingles vaccine: Should I get it?
  446. Sick sinus syndrome
  447. Silent heart attack
  448. Sinus headaches
  449. Sinus infection and toothache: Any connection?
  450. Sjogren's syndrome
  451. Small cell, large cell cancer: What this means
  452. Small vessel disease
  453. Smallpox
  454. Somatic symptom disorder
  455. Soy: Does it worsen hypothyroidism?
  456. Staying active with Crohn's disease
  457. Stomach cancer
  458. What is stomach cancer? A Mayo Clinic expert explains
  459. Stomach cancer FAQs
  460. Heart disease prevention
  461. Strep throat
  462. Strep throat in young children: A common diagnosis?
  463. Sudden cardiac arrest
  464. Sudden death in young people: Heart problems often blamed
  465. Sun damage
  466. Sunburn
  467. Takayasu's arteritis
  468. Teen depression
  469. Test anxiety: Can it be treated?
  470. Thalassemia
  471. The dawn phenomenon: What can you do?
  472. Thyroid disease: Can it affect a person's mood?
  473. Thyroid peroxidase antibody test: What is it?
  474. Tips for easing stress when you have Crohn's disease
  475. Tips to make your mornings easier
  476. Tonic-clonic (grand mal) seizure
  477. Toxic hepatitis
  478. Toxoplasmosis
  479. Transplants
  480. Treatment of parathyroid disease at Mayo Clinic
  481. Treatment options for biliary tract cancer
  482. Treatment-resistant depression
  483. Tricuspid atresia
  484. Tricuspid valve regurgitation
  485. Tricyclic antidepressants
  486. Tuberculosis
  487. Tumor vs. cyst: What's the difference?
  488. Type 1 diabetes
  489. Type 1 diabetes in children
  490. Type 2 diabetes
  491. Type 2 diabetes in children
  492. Typhoid fever
  493. Ulcerative colitis
  494. Ulcerative colitis flare-ups: 5 tips to manage them
  495. Understanding complement 3 glomerulopathy (C3G)
  496. Valerian: A safe and effective herbal sleep aid?
  497. Valley fever
  498. Vasculitis
  499. Vegetarian diet: Can it help me control my diabetes?
  500. Ventricular septal defect (VSD)
  501. Vicks VapoRub: An effective nasal decongestant?
  502. Video: Heart and circulatory system
  503. How cancer spreads
  504. Mitral valve regurgitation
  505. PICC line placement
  506. Grateful patient talks about his Mayo Clinic experience
  507. Viral hemorrhagic fevers
  508. Vitamin B-12 and depression
  509. Vitamin D and MS: Any connection?
  510. Vitamin deficiency anemia
  511. Vitamins for MS: Do supplements make a difference?
  512. Von Willebrand disease
  513. Walking pneumonia
  514. Warm-mist versus cool-mist humidifier: Which is better for a cold?
  515. Watch an interview with Fernando C Fervenza MD PhD
  516. West Nile virus
  517. Heart failure action plan
  518. What is biliary tract cancer?
  519. What's the difference between H1N1 flu and influenza A?
  520. When cancer returns: How to cope with cancer recurrence
  521. Where can I learn more about living with Crohn's disease?
  522. Whiplash
  523. Whipple's disease
  524. White stool: Should I be concerned?
  525. Whooping cough
  526. Whooping cough
  527. Why isn't there a hepatitis C vaccine?
  528. Wilson's disease
  529. Effectively managing chronic kidney disease
  530. Do zinc supplements shorten colds?