Basics
Fatigue is a tiredness that is not relieved by rest. It can be a symptom of an underlying medical or psychological condition or a result of poor lifestyle choices, report doctors at the Mayo Clinic. Although fatigue often is accompanied by the desire to sleep, the tiredness runs deeper and affects motivation and attitude.
Many cases of fatigue are due to stress and sleep deprivation. Poor diet and lack of exercise can also contribute to fatigue. Depression and grief often create a state of lingering fatigue that also can cause irritability. Many people with chronic medical conditions such as AIDS, heart disease, thyroid disorder or diabetes become exhausted from the unrelenting symptoms of their disease. Patients undergoing extensive medical treatments, such as chemotherapy for cancer, are prone to fatigue.
Chronic fatigue syndrome is a condition that is not entirely understood, report Mayo Clinic doctors. The illness is characterized primarily by fatigue that is worsened by exercise and mental activity, but is not relieved by any amount of rest. Theories about the cause of chronic fatigue syndrome range from psychological stress to infections.
Mental Health
No matter the cause, fatigue can take its toll on patients' mental health. Those suffering from fatigue lose the motivation to be involved in activities they previously enjoyed and can become socially isolated. While mental illnesses such as depression can cause fatigue, the condition is exacerbated by the fatigue, and patients can become even more depressed. People with undiagnosed chronic fatigue syndrome, or anyone unable to find a reason for persistent fatigue, can become frustrated and depressed over a lack of understanding and treatment. People who suffer from fatigue begin to miss work and other obligations. Long-term fatigue can cause apathy, leaving patients uncaring about their own welfare or treatment.
Physical Health
Fatigue causes reflexes to slow down and can contribute to automobile and work-related accidents. Fatigue generally causes headaches, dizziness and loss of appetite. The combination of lack of motivation and lack of nutrition leads to sedentary lifestyles that breed heart disease and muscle weakness. The immune system reacts to chronic fatigue and puts patients at higher risk for infection. Doctors at Cancer Supportive Care Programs report that fatigue can result in anemia and muscle deconditioning. Inactivity and bed rest lead to muscle atrophy and weakness. Muscles that are not active lose the ability to maximize the flow of oxygen, resulting in the need for more oxygen and more effort to move. Fatigue also tends to interrupt daily activities such as bathing and other self-care habits that lead to additional muscle atrophy and reduced range of motion.
