MedicineNet - Fatigue and Tiredness

Symptom Checker: Symptoms & Signs Index

Medical Author:

Symptoms & Signs

Tiredness is not a symptom that defines any one particular disease. Rather, tiredness can be a symptom of many different diseases and conditions. Causes of tiredness range from lack of sleep and over exercise to medical and surgical treatments. The lack of energy associated with tiredness can sometimes cause difficulty with normal daily activities, leading to problems with attentiveness and concentration.

Fatigue, in medical terminology, refers to the state of reduced capacity for work or accomplishment following a period of mental or physical activity. For example, muscles fatigue if the are called upon to repetitively work for an extended period. Most of the causes of tiredness are also associated with fatigue.

Summary of Common Fatigue Symptoms by MedicineNet Staff
A review of our Patient Comments indicated that people with fatigue may also have coexisting symptoms. Patients indicated that they had difficulty functioning because they felt like they were carrying a heavy weight or they felt depressed. Others experienced weight loss, sweating, and diarrhea. Read on to learn more about fatigue symptoms in our Patient Comments.

Medically Reviewed by a Doctor on 2/24/2012

Health concern on your mind? Visit the Symptom Checker.


Fauci, Anthony S., et al. Harrison's Principles of Internal Medicine. 17th ed. United States: McGraw-Hill Professional, 2008.

Symptoms & Signs A-Z List

Chronic Pain/Back Pain

Find tips and advances in treatment.