Are you tired, fatigued or sleepy – how’s your sleep?

Are you tired, fatigued or sleepy- is there a difference?

Abstract: Most of us get tired at some time, many have experienced fatigue or sleepiness, hopefully at the end of a busy day. But what if it’s during the day or even upon awakening. Naming the feelings is important for communication and the approach to correcting the problem.

In many cases they may be linked.  


Feeling tired is a feeling of a reduced capacity for work, efficiency or accomplishment, usually accompanied by a sense of weariness and fatigue that can be mental, physical or both.

The  symptoms may be difficult to describe and words like lethargic, exhausted and tired may be used. It’s a feeling when you feel that sleep may help.

Tiredness is not a singular symptom that defines any one particular disease. Rather, tiredness can be a symptom of many different diseases and conditions.

The causes of tiredness range from lack of sleep or even excessive work, again either physical or mental. It can also result from significant medical or surgical problems.


Fatigue is a feeling of chronic tiredness or exhaustion, which often involves muscle weakness too. The fatigue becomes chronic when it lasts for a month or longer.

Fatigue is more of a feeling of being “dragged out”. Chronic fatigue or Chronic fatigue syndrome (CFS) are however, not the same.

Chronic fatigue can be associated with many conditions while CFS is a syndrome (a collection of certain specific symptoms) and CFS is not obviously associated with a specific cause and is characterized by a duration of 6 months or longer.

Fatigue is manifested in various symptoms and may be associated by sadness and exhaustion without being able to define it exactly. In other cases, individuals present with it without even knowing that they are fatigued.

Unfortunately, even after a comprehensive history, in about a third of patients the cause cannot be not found, and the diagnosis is not known. That is not to say that there is no fatigue felt, just that a cause can’t be found.

These symptoms are not unlike pain in general, in that they are personal to the individual. They are experienced by the individual and often not only difficult to be explained, but also difficult to be understood by others. Just like pain however, that doesn’t mean that it doesn’t exist.

In medical terms, Fatigue refers to the state of reduced capacity for work or accomplishment following a period of mental or physical activity, in other words, it’s a normal resting period.

For example, muscles become fatigued after repetitive work for an extended period. Most of the causes of tiredness are often also associated with fatigue.


Lethargy refers to a state of lacking energy. People who are experiencing fatigue or tiredness can also be said to be lethargic because they have low energy. The same medical conditions that can lead to tiredness or fatigue can also lead to lethargy.


Exhaustion is an extreme of either tiredness or fatigue. If you become exhausted walking upstairs, that’s an extreme of tiredness and may indicate a medical condition, a description of being exhausted at the end (or before) of the day may indicate other issues, which may alternatively be physical, mental or medical.

One of the most common complaints clinicians hear when taking a medical history of a current illness is that the patient states that they can’t understand why they feel so tired.

Therefore, to focus on the “implied reason” for the visit, potentially risks missing the underlying cause of the tiredness.

If the questions about “being tired,” is skipped, information or clues about the patient’s illness may be overlooked and therefore completely overlook a potential diagnosis and treatment for the patient.

Therefore, the first thing to understand about “tired” is what the patient means by their understanding of tired, fatigued or sleepy.

Fatigue is mainly a symptom and not a disease in itself. The key is for the doctor, with the patient’s help, to discover the underlying cause of fatigue wherever possible.

The patient’s input is important because accurate answers to the doctor’s questions may lead the doctor toward a diagnosis or, at least, may suggest what medical tests may help provide a diagnosis.

Equally however, there are reasons that are “normal” for a person to be tired. Normal people who have intense physical or mental challenges can become fatigued. If the intense activity is halted (for example, “Whew! The exam is over”… or… “I had to really run to catch ‘ the bus”), the fatigue gradually dissipates over hours or a day.

When patients describe longer-lasting fatigue or fatigue with otherwise normal activity, then it may be telling the patient and their doctor there is a significant underlying cause of tiredness.


Sleepiness on the other hand, is characterised by difficulty in concentrating, a strong need to sleep as would be seen, if the patient fell asleep inappropriately.

Nodding off in a warm room in a comfortable chair is normal but excessive sleepiness can be dangerous, especially when driving or operating machinery.

Excessive daytime sleepiness (EDS) may be the sign of a sleep disorder and should be investigated.

Generally speaking, women are twice as likely to report fatigue. While it is not known whether is gender specific, it may also be that women are better able to recognize the symptoms, basically, ‘know their bodys’ better’.

In association – co morbidity.

Temporomandibular joint dysfunction (TMD) and facial pain is another example involving unclear reporting which has also directed many to have even determined different causation to fit inaccurate reporting and fact. It too has a relation to sleep disorders.

Fatigue is not age specific either, occurring as it does at any age, nor  does it appear related to educational level. It is strongly related to the kind of work being performed and how rest and activity periods are managed.

People are more likely to be fatigued at either end of the spectrum, too much or too little activity. This is apparent in both physical and mental activity.

Chronic fatigue Syndrome (CFS)

Indeed, on the extreme, when Chronic fatigue Syndrome (CFS) was first identified, it was thought that this disorder occurred primarily in Caucasian women with high levels of education and social achievement with an onset of 30 years.

However, this has been disproven, several studies disagree with this, CFS have in many studies shown to be as common in men as women, again those reporting it are not equal.

Higher incidence in Afro-Americans than in Caucasians or Asians indicate that just about anyone can be diagnosed so.


There is little doubt that pain affects sleep and poor or deprivation lowers the pain threshold, clearly therefore the sleep, pain, fatigue and sleepiness factors are most likely strongly related.


Good sleep is crucial to good health and longevity.

Dr. Stephen Bray 2019

Leave a Reply

Your email address will not be published. Required fields are marked *