Fatigue affects almost everyone at some point in time. It can be a normal response to overexertion, stress or minor illness (such as a cold). However, it can also be a symptom of a medical condition or serve as a signal that a disease has progressed or worsened.
Fatigue can show up in a number of different ways, including:
- Daytime sleepiness
- Lack of energy
- Generally feeling tired
Most people can recover from fatigue due to non-medical origins in a relatively short period of time. However, continually getting inadequate amounts and quality of sleep can create a sleep debt even in otherwise healthy people. Long-term sleep debt can cause health problems that require medical attention. Fatigue alone can also significantly influence the ability of people to function.
Among the many factors that may cause fatigue are allergies and asthma. The overactive immune system response associated with allergies and asthma can be taxing on the body and cause fatigue. Therefore, fatigue is one symptom that may lead to a diagnosis of these conditions.
For people with asthma, fatigue can also be an important warning sign that existing treatments are not effectively controlling asthma symptoms. Asthmatics should take episodes of fatigue seriously and consult their physician. Fatigue may be a sign of impending asthma attack or respiratory failure.
Fatigue may also be a side effect of asthma or allergy medication (e.g., anticholinergics, oral steroids, leukotriene modifiers, antihistamines).
Fatigue that is related to a lack of sleep can only be addressed by getting sleep. For people with medical conditions, sudden incidents of fatigue should be followed by a trip to the physician and/or hospital. A combination of illness and disturbed sleep may be a significant barrier to patient recovery.
Physicians may perform a variety of diagnostic tests to determine the origin of the fatigue. Recommended treatment methods will focus on achieving adequate rest and address any underlying medical conditions causing fatigue.
Fatigue is a condition related to many non-medical and medical causes. Serious illness, minor infections, psychological medical conditions (e.g. depression), allergies and asthma may cause fatigue. Physical conditions not related to disease may also cause fatigue, such as pregnancy.
Overexertion and emotional stress may cause short-term fatigue, but these are normal responses and are not a symptom of an underlying medical condition that requires investigation. However, fatigue may also be a sign of a more serious physical or psychological disorder. Fatigue that is not relieved over several days with additional sleep and adequate nutrition should be discussed with a physician.
Long-term fatigue has negative effects on the physical and psychological state. Important brain activities occur during sleep, and insufficient sleep will reduce the person’s ability to function. Fatigue contributes to difficulty waking, low motivation, low performance and production levels, daytime sleepiness and irritability.
Chronic fatigue syndrome (CFS) is a controversial condition that may be related to immune system disfunction. The Centers for Disease Control and Prevention (CDC) estimates that 500,000 Americans have CFS. Though this condition remains the subject of debate within the medical community, some proponents believe there are connections between CFS and allergies. The syndrome is characterized by severe and debilitating fatigue.
There are many different potential origins of fatigue and these multiple origins may cause different symptoms. Individuals should seek medical care for fatigue under the following conditions:
- Fatigue comes on suddenly with no known cause
- Fatigue is not relieved by adequate rest, nutrition or removal of stressful factors
- Loss of personal and work productivity due to fatigue
- Passing out for no reason
- Unexplained chest pain
- Unusual bleeding
- Unexplained weight changes
Link to allergies and asthma
Fatigue, allergies and asthma are often related. In both allergies and asthma, the body is overtaxed due to the immune system response involved with these conditions. When breathing difficulties occur, the body may not be receiving sufficient quantities of oxygen, causing all the body’s systems to have to work harder to function. As a result of this overwork, the body becomes fatigued.
Though fatigue may be a symptom of undiagnosed asthma, it also plays a role in asthma management for people already diagnosed. Fatigue can signal that current treatment plans are not effectively assuring that the body receives enough oxygen. It can therefore be an early warning sign of impending respiratory failure. Asthmatics should take episodes of fatigue seriously and consult their physician.
Nearly 75 percent of asthma patients experience increased symptoms at night, according to the American Academy of Allergy, Asthma and Immunology (AAAAI). Allergy symptoms such as nasal obstruction can also affect a patient’s ability to sleep, leading to daytime fatigue. Medications can often be used to control allergy and asthma symptoms and prevent them from keeping patients awake.
It should also be noted that the use of certain asthma and allergy medications (e.g., anticholinergics, oral steroids, leukotriene modifiers, antihistamines) can lead to fatigue.
Impact of fatigue on overall health
Fatigue results in people being unable to function normally. The occasional sleepless night is normal. Long-term fatigue (illness related or not) impacts productivity and performance at school and at work. It also influences the ability to carry out household maintenance and chores. Fatigue increases the risk of errors, injuries and accidents.
Sleep deprivation accounts for an estimated 100,000 automobile crashes annually and about 1,500 fatalities at a cost of $12.5 billion, according to the U.S. Highway Traffic Safety Administration.
A long-term lack of sleep leads to the accumulation of “sleep debt.” Most adults require a minimum of eight hours of sleep per night. Children and adolescents require more sleep, generally a minimum of 10 hours a night is recommended. A sleep debt builds when the body requires sleep but does not get it. Merely cutting one hour of sleep out of the eight required daily will build up a sleep debt of five hours by the end of one work week.
There is only one way to manage sleep debt and that is getting extra sleep. Adequate sleep, along with good nutrition and exercise, are the main components of a healthy lifestyle.
Potential causes of fatigue
Millions of people at various times in life experience fatigue. The origin of fatigue may be difficult to medically diagnose. It can originate from many different causes including:
- Medical origins, including serious and chronic illness, minor infections, allergies or asthma
- Psychological origins, such as depression, anxiety, stress or grief
- Physical origins, such as pregnancy, inadequate nutrition, sleep debt, lack of sleep and sleep disorders
A number of other medical problems can also cause fatigue. These include:
- Respiratory conditions, such as chronic obstructive pulmonary disease (COPD), bronchitis and emphysema.
- Medications can cause fatigue, or cause sleeplessness that creates fatigue. For instance, the asthma drugs anticholinergics, oral steroids and leukotriene modifiers can cause fatigue. Antihistamines used to treat allergies can also cause the condition. Patients should discuss the possible side effects of their medications with their physicians.
- Anemia (a blood disorder).
- Heart and lung disease.
- Crohn’s disease (a gastrointestinal disease).
- HIV infection (the virus that causes AIDS).
- Lupus (an autoimmune disease).
- Rheumatoid arthritis.
- Thyroid problems.
- Chronic fatigue syndrome.
- Diseases passed by animals (e.g. rabies).
Diagnosis methods for causes of fatigue
The physician may perform a variety of tests to rule out certain medical causes of fatigue. This generally begins with a detailed medical history and complete physical examination. Testing that may be performed includes:
- Laboratory tests such as urine and blood tests.
- X-rays. An image is created of part of the body by using low doses of electromagnetic radiation reflected on film paper or fluorescent screens. X-rays can be used to diagnose a wide range of conditions, from bronchitis to a broken arm.
- Pulmonary function tests (PFT). Record both an individual’s capacity to breathe in (inspiration) and to breathe out (expiration). PFTs measure several different aspects of lung function to diagnose lung conditions.
- Electrocardiography (ECG). Evaluates the status of the cardiac system by recording the electrical potential generated by the heart.
- Computed axial tomography (CAT) scans. Produce cross-sectional images of any number of body systems, including respiratory, neurological, gastrointestinal and musculoskeletal systems.
- Magnetic resonance imaging (MRI). Produces cross-sectional images of the body and can “see through” bone and fluid-filled soft tissue.
If asthma or allergies are a suspected cause of fatigue, a number of specialized tests may be performed
Treatment and prevention of fatigue
The treatment and prevention of fatigue are related to the origin of the symptom. There are three potential causes of fatigue:
- Medical. Medical disorders and associated fatigue will require specific approaches according to the patient’s condition. For allergies and asthma a three-fold approach of avoiding allergens or environmental triggers, strict adherence to prescribed medications and following physician advice will help to alleviate the symptoms that are causing fatigue.
Chronic fatigue syndrome (CFS) may not be truly treatable. This is one reason why CFS is such a debilitating disease. The course of CFS varies significantly from one person to another. Clinical studies of the disease are lacking and the actual percentage of people who recover from CFS is unknown.
- Psychological. Anxiety, stress, grief and depression are commonly signified by fatigue. Psychological fatigue may require consultation with a physician for necessary medications (e.g., antidepressants), or counseling with a therapist. Since stress and anxiety can cause fatigue, which may lead to an increase in asthma symptoms or bring on an asthma attack, it is especially important for individuals with asthma to minimize the levels of stress and anxiety in their lives.
- Physical. The physical causes of fatigue include pregnancy, inadequate nutrition, inadequate rest and sleep disorders, among others. Inadequate rest and nutrition can only be remedied by achieving adequate rest and nutrition.
A variety of treatments may be recommended depending on the nature of the problem causing fatigue. Fatigue may be helped or eliminated by changing diet, sleep habits and dealing with physical and psychological issues.
However, a person with fatigue should consult a physician under the following conditions:
- Fatigue that lasts longer than two weeks
- Abnormal bleeding (e.g. rectal bleeding, vomiting blood)
- Unexplained weight loss or gain
- Increased breathing difficulty
- Fatigue that is not relieved by adequate rest and nutrition
- New masses, bumps or lumps in the body
- Mild to moderate pain in the head, chest and abdomen
- Fatigue accompanied by unexplained symptoms
- Severe headache, abdominal, pelvic or back pain
- Other people or pets in the household have the same symptoms
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about fatigue:
- Is my fatigue a cause for concern?
- What tests will you use to determine the cause of my fatigue?
- Is my fatigue related to my allergies/asthma?
- What treatments are available to me?
- When can I expect the fatigue to subside?
- Should I expect to experience asthma/allergy-related fatigue again in the future? If so, how often?
- How can I prevent asthma/allergy-related fatigue?
- Will you be changing the medications I am on?
- Do I require extra sleep?
- Under what circumstances should I consult a physician for fatigue?