Physical and mental fatigue are different, but they often occur together. Long-term physical exhaustion can also lead to mental fatigue.
Poor sleep can lead to fatigue if ongoing, and according to the Centers for Disease Control and Prevention (CDC), 1 in 3 Americans say they do not get enough sleep. The National Heart, Lung, and Blood Institute (NHLBI) recommend sleeping 7 to 8 hours a day for adults over 18 years of age.
Poor sleep is associated with a variety of medical problems and health conditions. These include:
- high blood pressure
- heart disease
Lack of sleep can prevent a person from fulfilling their usual tasks. It can make it hard to get out of bed in the morning. When it affects safety, for example, on the road, it becomes a public health concern. In severe cases, a person may show signs similar to that of an intoxicated state.
Fast facts on fatigue:Here are some key points about fatigue. More detail is in the main article.
- Fatigue can be due to a variety of medical conditions and health problems..
- Some causes can include anemia, thyroid conditions, diabetes, lung and heart disease, and having recently given birth.
- If a health condition, such as diabetes, is diagnosed and properly managed, the fatigue may go away.
- A healthful diet and regular physical activity can help reduce fatigue for many people.
Fatigue can make it hard to stay awake or to get up in the morning.
There are different types of fatigue.
Physical fatigue: A person finds it physically hard to do the things they normally do or used to do, for example, climbing stairs. It includes muscle weakness. Diagnosis may involve a strength test.
Mental fatigue: A person finds it harder to concentrate on things and stay on task. The person may feel sleepy, or have difficulty staying awake while working.
Sleepiness or fatigue?
Sleepiness can happen when a person does not have enough good-quality sleep, or when there is a lack of stimulation. It can also be a sign of a medical condition that interferes with sleep, such as sleep apnea or restess leg syndrome.
Typical sleepiness is more likely to be short term. Sleepiness and drowsiness can often be solved by getting regular and consistent sleep.
Fatigue, especially chronic fatigue, is usually linked to a medical condition or health problem. It may also be its own chronic condition known as myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS).
Fatigue is associated with many health conditions.
1) Mental health issues
It can result from stress, bereavement and grief, eating disorders, alcohol abuse, drug abuse, anxiety, moving home, boredom, and divorce. It can occur with clinical depression, either due to the depression itself, or because of associated problems, such as insomnia.
2) Endocrine and metabolic reasons
Conditions such as pregnancy, Cushing’s disease, kidney disease, electrolyte problems, diabetes, hypothyroidism, anemia, and liver disease can all lead to fatigue.
3) Drugs and medications
Some antidepressants, antihypertensives, statins, steroids, antihistamines, medication withdrawal, sedatives, and anti-anxiety drugs can cause fatigue. Changes in doses or stopping medications can also be a cause.
4) Heart and lung conditions
Pneumonia, arrhythmias, asthma, chronic obstructive pulmonary disease (COPD), valvular heart disease, coronary heart disease, congestive heart failure, GERD, acid reflux, and inflammoatory bowel disease (IBD) can cause fatigue, among many other heart, lung and digestive diseases.
5) Sleep problems
Working late, shift work, jet lag, sleep apnea, narcolepsy, insomnia, and reflux esophagitis can lead to a lack of sleep and fatigue.
6) Chemicals and substances
Vitamin deficiencies, mineral deficiencies, poisoning, and consuming too many caffeinated or alcoholic beverages may disrupt normal sleep, especially if these are consumed too close to bedtime.
7) Various diseases, conditions, states, and treatments
Cancer, chemotherapy, myalgic encephalomyelitis (ME), radiation therapy, chronic fatigue syndrome (CFS), fibromyalgia, systemic lupus, rheumatoid arthritis, obesity, massive blood loss, and weakened immune systems can all cause fatigue.
Fatigue can also be a sign of infection. Some infections that cause extreme tiredness include malaria, tuberculosis (TB), infectious mononucleosis, cytomegalovirus (CMV), HIV infection, flu, and hepatitis, among many others.
8) Chronic pain
Patients with chronic pain often wake up frequently through the night. They typically wake up tired and poorly rested, unable to get good quality sleep. The combination of pain and lack of sleep can cause persistent tiredness and fatigue.
Some diseases and conditions where pain is the main symptom, such as fibromyalgia, may also be linked to other conditions, such as sleep apnea. This further worsens syptoms of fatigue. In one study on fibromyalgia and sleep, half of the individuals with fbromyalgia also had sleep apnea.
9) Being overweight or underweight
Being overweight increases the risk of fatigue, for various reasons. These include having to carry more weight, being more likely to have joint and muscle pain, and being more likely to have a condition where fatigue is a common symptom, such as diabetes or sleep apnea.
Similarly, a person who is underweight may tire easily depending on the cause of their condition. Eating disorders, cancer, chronic disease, and an overactive thyroid, can all cause weight loss along with excessive tiredness and faituge.
10) Too much or too little activity
A person who feels fatigued may not exercise, and lack of exercise can cause further fatigue. Lack of exercise may eventually cause deconditioning, making it harder and more tiring to perform a physical task.
Fatigue can also affect healthy individuals after prolonged, intense mental or physical activity. Working or staying awake for long hours without a break, especially when driving, increases the risk of errors and accidents. Statistics have shown that, among truck and bus drivers, longer hours of staying awake lead to more motor vehicle accidents.
It is important not to drive while sleepy. A survey carried out by the CDC found that around 1 in 25 drivers aged 18 years and above had fallen asleep while driving in the previous 30 days.