Fatigue, Stress, Anxiety and Depression—the Differences

October 4, 2019

Have you ever noticed that popular media often uses the terms fatigue, stress, anxiety and depression interchangeably? As a matter of fact, you can easily find screening tests online for any and all combinations of these terms. It’s very confusing to say the least. Especially if you feel you may be experiencing one of these conditions. Below, I’ve mapped out the differences in these four conditions and how one could possibly have an effect on another.

Unfortunately, fatigue is a common ailment in American society and in many cultures around the globe. Approximately 10% of people worldwide experience fatigue from persistent tiredness. Fatigue is classified as both mental and physical depending on its root cause, and each type of fatigue is “multifactorial in nature”—meaning it can have a variety of causes. Physical and/or mental fatigue is characterized by feelings of tiredness and exhaustion caused by overwork, stress, certain medications or illness. Often fatigue can be linked to lifestyle and behavioral factors such as lack of sleep, too little or too much physical activity, use of alcohol or drugs, unhealthy diet, and jet lag. In addition, chronic fatigue may lead to stress, anxiety, and cardiovascular diseases. Studies indicate that stress increases the secretion of catecholamines and cortisol—hormones often used as stress indicators associated hypertension, myocardial infarction and stroke.

In general, stress is a broad term used to describe the brain’s response to any demand or set of demands resulting in a vast number of differentiated emotional and biological states. Basically, there are two types of demands or “stressors” that contribute to stress in humans:
(1) external / environmental stress, and (2) internal / emotional stress. For example, environmental stress is external, such as a project deadline, and stress that is internal may be caused by persistent fear or worry. People experience stress on a daily basis and it is considered a normal part of life. However, not all stress is equal. Scientists describe two types of stress:

1. Distress is negative stress that causes anxiety or unpleasant feelings that can lead to mental and physical issues.
2. Eustress is considered positive stress characterized by feelings of motivation, energy and excitement.

Continuous exposure to distress increases our vulnerability to adverse health outcomes mentally and physically. For example, a person who persistently perceives environmental demands will challenge their ability to adapt. This may cause feelings of anxiety that could lead to depression and physical illness and disease. Other consequences include weight gain, sleep disturbances, and substance abuse.

Anxiety and Depression
Anxiety and depression is a combination often used in the scientific literature. They are the most common mental health disorders worldwide. Here in the US, mental health disorders are estimated to affect 9-18% of the adult population within a 12-month period.

Anxiety is characterized by feelings of tension, thoughts of worry, and physical changes such as elevated heart rate and blood pressure, perspiration, and dizziness. It is a normal response to stress and life events, however, if excessive, is unhealthy and can lead to depression.

The Anxiety and Depression Association of America claims co-occurrence is not uncommon and an individual with an anxiety disorder may also experience depression or vice versa. Depression is a known risk factor for a number of chronic physical illnesses, including asthma, diabetes, heart disease and strokes. Symptoms of depression include feelings of sadness, hopelessness, guilt, decreased energy, difficulty concentrating, insomnia, and thoughts of suicide. It is estimated 20-25% of those who experience major stressful events develop anxiety and/or depression.

What to do
If you are feeling any of these conditions the American Anxiety and Depression Association offer information and support in understanding the facts and offering support.


Here is a link to tips of coping strategies when you are feeling anxious or stressed:

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