What is fatigue compared to tiredness?
A sensation of tiredness before, during or after activities is known as fatigue. Normal fatigue varies as people carry out their daily activities and responsibilities. The body’s intelligent design acts to alert an individual to cease an activity with a feeling of weariness, weakness or lack of energy. The feeling of fatigue is an important sensation in order to prevent overuse, overload and over-activity. Cessation of activity completes a variety of cycles, especially the sleep/wake cycle. During the sleep phase, the body and brain shut down in order to renew energy, hormones, and consolidate learning and memory.
Everyone experiences fatigue at the end of the day and during daily circadian rhythm cycles. An afternoon drop in energy occurs for most people during a low period in the circadian rhythms, the body’s internal clock. People may yawn, want to take a nap, or feel like they need an energy boost, like a cup of coffee. Fatigue sensations will vary according to the individual. The degree, frequency and duration of fatigue varies and depends on many transient and permanent conditions. Some people are “morning people” and feel more fatigued at night. Others are “night people” and feel weary in the morning.
When normal cycles are disrupted, significant fatigue becomes a complaint. Some occupations may cause more fatigue than other work types. Some medical conditions carry prominent risk of fatigue. When a symptom of fatigue is noticed, feels abnormal, occurs over a period of time, and causes significant problems, classification and medical treatment may be necessary. Duration of symptoms:
- Symptoms lasting less than one month – recent fatigue.
- Symptoms lasting more than one month – prolonged fatigue.
- Symptoms lasting more than six months – chronic fatigue.
Types of Fatigue
Fatigue is a symptom indicating a certain cause in most cases. Many times a medical cause can be uncovered and treated. Some mental conditions like depression can cause fatigue. In other cases, the cause cannot be found. Fatigue incidence from any source is estimated between 4-33% of the population. Women have a higher incidence of fatigue than men. At least 2/3 of fatigue cases are attributed to medical conditions and psychiatric disturbances. The most frequently diagnosed causes are depression, panic disorder, virus, upper respiratory infection, anemia, and medications. Family and relationship problems and workplace stress are common triggers for fatigue. Additional classifications:
- Battle Fatigue – also known as shell shock, post traumatic stress disorder, and combat stress disorder. Military, law enforcement, firefighters, medical personnel and civilian support personnel experience repeated action in war, civil disturbances, and even peacekeeping. They can often develop symptoms including fatigue.
- Exercise Fatigue – when an individual reaches a state of muscular failure after a bout of physical exercise. This state is often desirable for the participant. When muscles are allowed to reach fatigue or momentary muscular failure, the body adapts and grows stronger.
- Decision Fatigue – mental tiredness can affect everyone. Constant decision making during the day is the norm for almost everyone. The brain can become fatigued with the array of options and consequences. Those in particularly high decision jobs like legal judges, are extremely susceptible to decision fatigue. Many times this type of fatigue manifests are paralysis. The brain on overload decides to do nothing, which is actually a decision and carries consequences.
- Industrial Fatigue – work performance can vary during tasks and time periods on the job. Long periods at work and doing repetitive or monotonous tasks can decrease abilities and motivation. The hours at the end of a shift are likely to be impaired for almost all workers. Some occupations can have increased physical fatigue and/or psychosocial fatigue. Stress components like overnight work, long hours, bullying, sexual harassment, low control and power have associations with fatigue. Healthcare workers, including physicians and nurses often have problems with fatigue and many medical errors are directly due to fatigue. Air traffic controllers can also have dangerous levels of fatigue. Generally, if a person sleeps less than six hours or is awake for more than 16 hours, fatigue can set in and lower performance.
- Listener Fatigue – listening devices with earphones that seal the ear canal can lead to listening fatigue. When sound waves enter a sealed ear canal they can increase pressure. The increased pressure triggers the acoustic reflex, a defense mechanism. Sound energy is dampened causing the listener to turn up the volume. The eardrum experiences physiological strain and causes listener’s fatigue.
- Driver Fatigue – professional drivers and all drivers can experience driving fatigue. Professional drivers face major problems physically and mentally. Sleep deprived drivers and drivers working overtime have slower reaction times, impaired memory, vision and hearing and reduced vigilance. Severe driving fatigue can be compared to alcohol impairment.
- Compassion Fatigue – also called burnout, and associated with post-traumatic stress disorder. Individuals in law enforcement, medical services, and those caring for children, elderly, sick and mentally incapacitated people, can reach a saturation point. Professional caregivers are very susceptible to compassion fatigue. Symptoms can include medical issues, absenteeism, relationship and sexual problems.
- Age Fatigue – advanced age has an effect on both the body and the brain. Muscle mass diminishes and the brain become less plastic, or flexible. Skeletal muscle fatigue resistance is significantly lowered as an individual ages. Contractile velocity in skeletal muscle is highly dependent on age. Cerebral functions diminish with old age. Individuals are less able to multi-task, consolidate memory and make decisions.
- Pregnancy Fatigue – normal fatigue can occur with childbearing. Women often feel exhausted during the early stages of pregnancy. Hormonal changes, emotional ups and downs, nausea, vomiting, lack of sleep and increased urinary demands may cause this type of fatigue. Later stages of pregnancy can cause fatigue simply from carrying the extra weight. Increased musculoskeletal demands from extra weight can put a burden on joints, muscles, tendons and ligaments, causing fatigue.
- Social Fatigue – can occur for any individual exposed to social interactions. Introverts can experience fatigue earlier than extroverted people. In one experiment, researchers exposed fruit flies to other flies for varying time periods. Those flies who were exposed to the most social interactions slept significantly longer than the others, suggesting increased fatigue. Some people can become over stimulated by social media and withdraw from the technological tools constructed to help interactions with others.
- Life Stress Fatigue – cumulative stress over a lifetime can bear down on individuals and communities. Those who experience racial, sexual, gender, and economic discrimination, or who have suffered trauma like sexual abuse or natural disasters may become fatigued. While some stress is normal and a part of everyday life, repeated stressors may tax the immune system.
Chronic Fatigue Syndrome (CFS)
Fatigue is usually self reported, or brought to a physician’s attention by an individual. Physicians must attempt to sort through the origin, cause, and duration of the symptoms. If the cause is not found, a diagnosis of Chronic Fatigue Syndrome (CFS) may be given. CFS is diagnosed in only a small subset of fatigue cases, or about 1/3 of the time. America, the United Kingdom and Australia have an incidence of CFS in the general population of between 2-3 percent.
CFS patients complain of sleep disruption, muscle and joint pain, memory problems and emotional impairment. These symptoms persist longer than six months, are not related to any biological causes, and do not improve with sleep, rest, and activity restriction. Women are 2 to 3 times more likely than men to have CFS. The average age for CFS onset is between 30 and 40 years of age. The cause of CFS is yet unknown. The recent finding in 2009, that CFS was caused by a virus, is now disproven. Cell samples in that study were contaminated. Investigations into genetic, neurological, endocrine, viral and psychological factors continue.
Depending on the cause, treatment or lifestyle changes may provide a full recovery for about 10% of fatigue sufferers. Between 20-60 percent of fatigue patients can achieve partial improvement. Unfortunately, about 1/5 of all patients may worsen over time. Those with poor improvement or with worsening symptoms are usually older, have more severe symptoms, and greater psychiatric illness. Once medical conditions are treated and symptoms persist, patients are encouraged to increase exercise and seek psychological counseling. Medications are generally not used except for treatment of psychiatric symptoms. Long-term management may be necessary.
- Psychological disturbance – depression, panic and anxiety disorders can initiate, occur with, or occur after fatigue complaints.
- Female gender – women suffer from fatigue 2 to 3 times more often than men.
- Activity – either low levels of activity or high levels of activity can lead to fatigue.
- Genetics – CFS patients may have a family history of fatigue, however, psychiatric illnesses also may run in families. Data is inconclusive as research is limited in the genetic components of fatigue.
- Race – Black, Latino and Native Americans have a higher incidence of fatigue than white individuals.
- Age – individuals over the age of 60 often have a medical condition which causes fatigue.
- Locations – residences, work sites, and travel destinations may confer exposure to viruses or infectious agents. Tuberculosis, lyme disease, unpasteurized dairy products, contaminated water and even allergies to animals may cause fatigue.
- Drugs – street drugs and intravenous drug use can cause HIV/hepatitis B or C virus infection.
- Sexual intercourse – unprotected sex can cause infections.
- Sleep deprivation – insomnia and related sleep disorders disrupt the normal sleep/wake cycle and cause fatigue.
- Sedentary lifestyle – lack of exercise and the resulting diminishment of muscle mass can cause inefficiencies in the musculoskeletal system and lead to fatigue.
- Cardiovascular – heart failure, atrial fibrillation and related coronary disease impairs oxygen delivery through the blood.
- Diet – inadequate intake of calories, protein, carbohydrates, fats and minerals impairs energy production.
- Fatigue – not improved with sleep, rest or activity restriction.
- Memory impairment – short term memory is often impaired, with long-term memory not as problematic.
- Concentration difficulties – paying attention, processing information, multi-tasking and learning problems.
- Sore throat – on ongoing, and general soreness in the throat area.
- Musculoskeletal – common complaints of soreness, aching and stiffness in muscles and joints. May also be due to inactivity.
- Headaches – people with fatigue complaints often have new reports of headaches or a change in headache variety. Nausea and dizziness may also be present.
- Sleep disruption – fragmented sleep, difficulty falling asleep, staying asleep or early waking. Fatigue sufferers may attempt to sleep during waking hours, which further complicates sleep patterns.
Diagnosis of fatigue is usually initiated by an individual seeking medical attention. Physicians take a history, conduct a physical exam, order diagnostic tests and attempt to discover a medical or psychological cause. Multiple disorders have common physical symptoms of fatigue which complicates diagnosis. Since no specific cause is known for CFS, physicians often do not order expensive tests for fatigue. A process of deduction is conducted by ruling out likely causes. The history of an individual and an evaluation of risk factors may be the most important part and least expensive course of action in diagnosing fatigue.
Many patients with fatigue have no known history of fatigue, medical problems or psychological problems. They may report normal levels of activity, sleep, diet and social interactions. Fatigue symptoms may occur suddenly and when they persist, the individual may seek medical attention. A detailed record of historical patterns may be the key to uncovering the cause of fatigue. Screening questionnaires may help the patient and physician discover symptoms and causes.
- Patient-Reported Outcome Measurement Information System (PROMIS) – measures physical function, emotional distress, fatigue, pain, social health from the patient’s perspective.
- Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) – evaluates symptoms relevant to certain fatigue related medical conditions.
- SF-36v2 Vitality subscale – generic measures of health-related quality of life with the additional measurement of vitality or robustness of life.
- Patient Health Questionnaire (PHQ-2and PHQ-9) – screening instruments which evaluate frequency of symptoms related to depression.
- The CAGE Questionnaire – assesses alcohol dependence. Scores are based on the patient’s habits and feelings related to alcohol use.
The exam in the physician’s office may turn up a variety of symptoms or very little evidence of fatigue or chronic fatigue. Muscle pain, headaches, sore throat, enlarged lymph nodes, upper respiratory problems, muscle atrophy and obesity may be clear signals to the physician. However, in the case of fatigue, objective evidence is often not found. This does not mean that symptoms of fatigue are imagined or psychological in nature. Evaluation of medicines, psychiatric screening and further investigation with laboratory tests may be necessary.
Drugs associated with fatigue include over-the-counter medicines, street drugs, and prescribed pharmacological drugs. Physicians should also ask about supplements and diet factors that may have negative interactions with medicine. Some drugs known to cause fatigue:
- Neuroleptic agents
Fatigue patients often have psychological symptoms. Depression, anxiety disorders, and substance abuse are likely in up to 1/3 of patients with symptoms of fatigue. Somatization disorder is also seen in fatigue patients. They may experience real pain but no cause can be found. Psychiatric intervention, especially in early stages, may help uncover causes of fatigue.
People with fatigue, especially those with persistent and severe symptoms may expect to undergo standard and escalating laboratory testing. Physicians usually start with routine and inexpensive tests and escalate to extensive laboratory or imaging studies as necessary. These tests are not used to definitively diagnose CFS, but instead are used to rule out or identify conditions contributing to fatigue. The US National Institutes of Health recommends the following tests. Physicians may order all, some, or none according to several criteria:
- FBC with WBC differential – to find infections.
- ESR – to find inflammation.
- Urine toxicology screen – alcohol and drug use.
- Urea, Creatine, Electrolytes – for kidney dysfunction.
- Blood glucose – for diabetes.
- Calcium – for low or elevated levels.
- Phosphorus – possible bone and liver disease.
- TSH – for hypothyroidism.
- Total protein, albumin, and globulin – to find liver disease, infection and malignancies.
- Gluten sensitivity – for celiac disease.
- Creatine kinase – may find cardiac disease.
- CRP – to find inflammation.
The most common medical and psychological conditions found when attempting to diagnose fatigue are sleep disorders, infectious diseases, sleep apneas, depression, cardiovascular diseases, endocrine disorders, drugs, toxins, and the behavioral habits which contribute to these conditions:
- Stimulants – caffeine, nicotine, alcohol, quinine, tobacco, drug intoxication or withdrawal.
- Sleep disorders – insomnia, sleep apnea, periodic limb disorder, restless legs syndrome, sleep phase disorders like shift work and jet lag.
- Psychological – panic attacks, recurrent nightmares, post-traumatic stress disorder, depression, major depressive disorder, and somatization disorder.
- Prescription drugs – beta-blockers, theophylline, stimulants, decongestants, thyroid hormone, corticosteroids, SSRIs, monoamine oxidase inhibitors, and phenytoin.
- Hematological disorders – anemia, chronic myeloid leukemia, and lymphoma.
- Cardiovascular disease – heart failure, atrial fibrillation, myocardial infarction, and myocardial ischemia.
- Endocrine disorders – hypothyroidism, hyperthyroidism, diabetes mellitus, Addison’s disease, vitamin D deficiency, hypopituitarism, acromegaly, growth hormone deficiency, hyperthyroidism, Cushing’s syndrome, and diabetes insipidus.
- Infectious disease – EBV also known as mononucleosis, HIV infection, Lyme disease, cytomegalovirus, toxoplasmosis, brucellosis, tuberculosis, and chlamydia.
- Pulmonary disease – chronic obstructive pulmonary disease (COPD), asthma, and pleural disease.
- Gastrointestinal disorders – celiac disease, chronic liver disease, and inflammatory bowel disease (IBS).
- Neurological disorders – Parkinson’s disease, stroke, and Multiple Sclerosis.
- Rheumatological disorders – fibromyalgia, arthritis, and rheumatoid arthritis.
- Cancer – all types of cancer.
Diagnostic Criteria for CFS
When none of the previously mentioned diseases, disorders and conditions explains fatigue, the fatigue lasts more than 6 months and 4 out of the following 8 symptoms are present, the diagnostic criteria for CFS is considered met:
- Memory or concentration difficulties
- Sore throat
- Tender lymph nodes/glands
- Muscular pain
- Joint stiffness
- Sleep disorders
- Fatigue which lasts longer than 24 hours, after exertion.
Treatment of fatigue consists of management of the cause, medical or psychological. Lifestyle, behavior and workplace stressor improvements may provide some relief for those without a medical or psychological cause of fatigue. For CFS patients, however, treatment strategies seek to manage symptoms and improve functional abilities.
Individuals with fatigue and CFS may benefit from customized and individual treatment plans, as long term management may be necessary. Care should be taken to set the patient up for success with convenient options, physician access, telephone, email and online support as CFS waxes and wanes over time. Assessments should be conducted in regular intervals and patients monitored for worsening symptoms. Psychological symptoms especially may become problematic, with depression developing due to reduced functional abilities.
Specific treatment for CFS includes:
- Sleep hygiene – discouraging prolonged bed rest, initiating and maintaining a sleep schedule, finding relaxing behaviors before bed, and the elimination of stimulating behaviors can be helpful.
- Medications for depression or sleep – selective serotonin-reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, and tricyclic antidepressants can treat depression. Anticonvulsants can regulate mood, reduce sleep disruption, and give limited pain control. Dosing starts at low levels and may be increased as needed. Medication side effects should be considered as some patients may be hypersensitive to medication.
- Graduated exercise therapy – CFS patients are often in poor physical condition due to fatigue, pain and exertion intolerance. Some people may have objections to an exercise program due to a lack of confidence in their abilities. A gradual approach to exercise is the recommended method. Consultation with a physical therapist initially may be the best course of action. An exercise program with structure and feedback presents the best outcome. The risk of overexertion is always present for anyone beginning an exercise program. Those with CFS may be particularly susceptible to over exertion. Low-impact exercise including walking, stationary bike riding and stretching are indicated for beginners. More strenuous activities can be added as tolerated. Swimming, yoga and weight lifting may be considered for intermediate exercisers. Running, sprinting, road bike riding, and group exercise class are indicated for advanced exercisers. Many exercises are individual choices as even exercise that is advertised as low impact or low energy may in fact be too much for a CFS patient. Frequent exercise of a short duration is favored over solitary sessions of long duration. Exercise tolerance and confidence will improve with time.
- Cognitive Behavioral Therapy (CBT) – personal, one-on-one counseling with a mental health professional. Skills are built by examining thoughts and behaviors which impact fatigue symptoms. Counseling seeks to provide education, self-control strategies, and guidance to become more functional. Treatment strategies may include family members to increase compliance with exercise, behavior and other recommended interventions.
- Alternative Therapies – chiropractic care, acupuncture, meditation, breathing exercises, guided imagery, massage therapy and homeopathic remedies including vitamins and supplements may be helpful. Essential fatty acid and magnesium supplements may improve the immune system and alleviate some symptoms.
Patients with CFS may face many barriers to health care. The main treatments for CFS are exercise and counseling. Exercising can be expensive and difficult to access depending on location. Those without medical insurance may not be able to afford counseling. Even those with insurance may not be able to access a qualified counselor. One option for CFS patients is to receive support at home from a nurse or to receive counseling on the telephone, by email or online. This type of care is known as pragmatic rehabilitation. Supportive listening options can significantly improve self-reported fatigue symptoms.
A device which can help athletes and fatigue patients may be available soon to aid in detecting when fatigue is reaching a level of concern. Before this device, athletes and people in general had to rely on their own sense of fatigue before cessation of activity. This reliance on an individual’s perception leads to overexertion. When fatigue and overexertion happens, pain, injury and loss of confidence may be the result. The device uses sensors on the muscles to report data to a recording computer. A better version is being developed which can be connected to an iPhone, is smaller and more portable. Developers see a wide market for certain occupations.
Researchers have found that central nervous system fatigue can show up in voice patterns. This non-invasive system is finding increased interest for health and workplace settings. Baseline or normal speech is recorded when a person is not fatigued. An acoustic analyzer then quantifies the changes in acoustics when a person becomes tired or fatigued. When fatigue progresses, an individual’s speech slows, pitch increases, tone decreases and more pauses are evident. Researchers believe that central nervous system and muscular force in the voice can give objective measurements of fatigue.
Individuals who are fatigued perform better in a group setting. Group thinking tends to raise performance levels overall even when all members of the group are fatigued. One study found that a fatigued individual’s performance was worse than an alert individual’s performance. But, when that same fatigued individual worked with a team, performance was equal to that of an alert individual. Flexible thinking seems to improve with social dynamics. This finding is important especially for occupations which require critical thinking and important decision making like health care workers.
Paticipants in a gum chewing research project experienced less fatigue after two weeks. Psychological status, physical and mental fatigue improved for the gum chewers. Anxiety was lowered. Cognitive measures like confusion showed improvement as well.
Music has recently been found to have positive pharmacological benefits for all people. Cancer patients were studied and treated with music medicine. Researchers concluded that interventions with music may have positive effects on mood, pain, anxiety and depression. In addition, physical symptoms may improve with better heart rate, respiratory rate and blood pressure.
Every person, of every age, race, gender or nationality has experienced the sensation of fatigue. Fatigue happens usually at night after a day’s work or after activities have been completed. This type of fatigue is normal and natural. The body begins to shut down in order to prepare for the sleep phase of a diurnal day. Sleep is a restorative process crucial for physical and mental health. The feeling of fatigue appears in order to motivate a person to initiate the sleep sequence or to stop an activity.
Abnormal fatigue can occur due to a medical, psychological or pharmacological condition. Anemia, cancer, and heart failure are medical conditions which can cause physical fatigue. Abnormal fatigue can occur due to mental conditions as well. Depressive disorders, compassion fatigue and battle fatigue are examples of mental fatigue. Over socializing or spending too much time on the computer with social media can also trigger symptoms of mental fatigue. Treatment for abnormal fatigue consists of treating the medical or psychological cause. In other cases, cessation of the activity or changing lifestyle and behaviors may improve or cure fatigue.
When a cause for fatigue cannot be found and persists for more than six months, chronic fatigue may be diagnosed. Clinical diagnosis is confirmed when at least four common symptoms are also present. Chronic Fatigue Syndrome (CFS) is not well understood and no known cause is agreed upon. Treatment for CFS consists of encouraging the individual to begin an exercise program and seek psychological counseling. Alternative therapies may be helpful in managing symptoms and improving self confidence.
Fatigue can be dangerous. Fatigued drivers who operate machinery, are more likely to get in accidents and those accidents may be more severe. Professional drivers and airline pilots have a known susceptibility to fatigue problems. Other occupations with a high degree of fatigue issues include physicians, nurses, law enforcement, firefighters and air traffic controllers. While recent research has exposed the dangers of fatigue, workplaces have to balance the demands of the job with practices to alleviate fatigue. Many times fatigue cannot be alleviated, as conditions cannot change. For example, military personnel experiencing battle fatigue must endure fatigue with serious detriments to their health.