Fatigue may be physical, mental, or emotional. Additionally, when one of these systems is affected, it tends to affect the others in turn. To be able to manage the overwhelming exhaustion that is fatigue, you must first understand what is causing it. Here’s a look at some common causes of fatigue.
Physical Fatigue
Physical fatigues are those you feel in the body. Common types of physical fatigue include muscle fatigue and adrenal fatigue. Muscle fatigue often results when the muscles are pushed to exert more force than they are used to. It commonly occurs during workouts or strenuous activities such as hiking. For people who are not used to working out, the process of working out can produce lactic acid, which is created from a lack of oxygen (i.e. heavy breathing, hyperventilating). Called anaerobic respiration, this production of lactic acid makes the muscles feel weak and sore. If you leap into a workout program your body isn’t ready for or fail to warm up properly, you may develop this type of physical fatigue. Additionally, physical exertion without key nutrients that keep your muscles healthy can also cause muscle fatigue.
Adrenal fatigue is a fatigue syndrome characterized by exhaustion. In this particular instance, physical fatigue is caused by an imbalance of certain hormones produced by the adrenal glands. However, it is important to note that “adrenal fatigue” is not medically recognized; adrenal insufficiency, or Addison’s disease, is considered an actual disease. Those with Addison’s disease are plagued by -- in addition to other symptoms -- chronic fatigue. This fatigue develops because the adrenal glands become damaged, and fail to produce the appropriate amounts of cortisol or aldosterone.
Having a chronic illness can also lead to chronic physical fatigue, particularly those characterized as an autoimmune disorder. When you have a chronic disease, your body is almost constantly attempting to fight against the illness in some way. Healing from serious trauma, such as traumatic brain injury (TBI), can be exhausting for your body. Other issues that commonly cause fatigue include substance abuse, medication, unhealthy lifestyle habits (from the things you eat to the schedule you keep), and insufficient activity.
Emotional Fatigue
In addition to the physical fatigue that often accompanies chronic diseases, these issues can also weigh on you emotionally, leading to feelings of depression, isolation, self-consciousness, blame, shame, and other strongly negative feelings that can create what is considered emotional fatigue. Just as there are multiple kinds of physical fatigue, many different things can lead to emotional fatigue. Depression, for example, is a mental health disorder that can bring its own kind of fatigue. The psychological and physical stress of constant depression can wear you out, body and mind.
Other kinds of emotional fatigue include stress fatigue and compassion fatigue. Stress fatigue appears similarly to depression, with the added input of the excess of stress hormones that are produced. Stress can also prey on the body physically, leading to cardiovascular and gastrointestinal issues that may create a physical fatigue as well.
Compassion fatigue, for the most part, is strictly an emotional burden. It is common among occupations in which you act as a caretaker, whether that role is teacher, doctor, psychologist, or other close caretaker. It can result after many years of tending to people who either cannot give back or who will never make any sort of recovery; another instigator of compassion fatigue might be when someone who is under your care undergoes an extremely painful event. For example, working in geriatric or hospice medicine rarely has a happy ending. Conversely, while being a psychologist might often be a very rewarding experience, you are subject to many people’s very intimate and excruciating feelings and experiences. It can be difficult to hear these things day in and day out without becoming emotionally exhausted.
Mental Fatigue
Mental fatigue revolves largely around cognition. It is often characterized as an inability to focus or pay attention, perhaps with difficulty making choices or finding correct answers. This can be brought on by long periods of intense study or work that requires intensive cognition. Additionally, issues like TBI can impact the presence of mental fatigue. During the recovery period, it can be harder to accomplish mental tasks that were very easy, which means more of your energy is put towards deciding which shirt to wear. Furthermore, the presence of emotional fatigues can impact your ability to turn your thoughts toward the issue at hand. For example, high levels of stress can divert your attention to the issues about which you are experiencing stress, requiring more effort than normal to focus on the current problem.
