Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at December 1, 2015

Lethargy is a symptom that can cause one to feel sleepy, fatigued, and sluggish. The sluggishness can be seen with movement or when thinking. One can be described as lethargic if they have the following symptoms: fatigue, low Energy, sluggishness, decreased concentration and alertness and changes in mood.


Definition & Facts

Lethargy can also be described as an extreme lack of energy, which can occur due to lack of exercise or sleep, a poor diet, overworking, or stress. Typically, lethargy is a normal response to any of these conditions and can be resolved with regular exercise, proper sleep, stress reduction, and a balanced diet.

However, in some cases lethargy may be a symptom of a more serious physical or psychological condition. Illnesses such as anemia, asthma, cancer, sleeping disorders, substance abuse, thyroid problems, and certain medications can all be causes of lethargy. If lethargy is persistent, meaning chronic, and it does not decrease or resolve with methods of self-care, it may be indicative of a deeper cause that may require one to seek medical attention.


By studying the pattern of lethargy and the accompanying symptoms, one can discover the cause. Progressive feelings of lethargy that increase throughout the day and accompanied by dry skin, constipation, and weight gain could indicate that it is caused by improper functioning of the thyroid gland.

If lethargy is noted in the morning and continues to persist throughout the day, it may be due to depression, extreme stress, or lack of sleep. If lethargy does not decrease with rest, exercise, and a proper diet, it may a symptom of a more serious condition, known as chronic fatigue syndrome. Lethargy can also be caused by problems with the respiratory and cardiovascular systems, such as pneumonia, asthma, COPD, heart failure, and cardiomyopathy.

Neurological and psychological conditions such as depression, dementia, grief, eating disorders, substance abuse, anxiety attacks, lack of exercise and being overworked can all cause lethargy as well. Certain diseases, such as anemia, diabetes, cancer, chronic pain, kidney disorders, liver disease, thyroid problems, sleep disorders, and rheumatoid arthritis can cause one to feel lethargic as a side effect.

Causes of lethargy that can be life threatening include drug overdose, hemorrhage, arrhythmia, serious infection, severe depression, acute heart failure, and trauma. In these cases, immediate medical attention is necessary to prevent a fatality.

When to see a doctor

Emergency medical attention may be required if lethargy comes on suddenly or if it is accompanied with the following additional symptoms:

Any noticeable, severe changes in behavior that are accompanied by lethargy are often a cause for concern. Immediate medical attention should be sought if one experiences thoughts of self-harm as well as lethargy.

If lethargy is accompanied by the following symptoms, immediate medical attention may not be necessary, but an appointment should be made with a physician as soon as possible:

Treatment & Therapy

A diagnosis of lethargy is the first step in identifying the cause and finding the proper treatment. For lethargy to be diagnosed, a physician may recommend a series of tests, such as urine, blood, and imaging tests. These are performed to rule out any other medical conditions that may be causing lethargy.

If a physician identifies an infection or an improper functioning thyroid as the cause of lethargy, the necessary medications will be prescribed. If depression or another mental health-related disorder is determined to be the cause, it is likely that medication for depression and anxiety will be prescribed. Treating depression makes it easier for one to cope with feelings of lethargy and can also help to improve sleep. If lack of sleep is causing feelings of lethargy, measures should be taken at home to promote rest.

These include avoiding caffeine, avoiding naps during the day or taking soothing baths prior to bedtime. If these measure are ineffective, a physician my prescribe sleep aids. If one lacks exercise in their daily routine, seeking assistance from a physical therapist can help determine what types of exercise should be incorporated into daily routines. People who are inactive often begin with simple stretching and range-of-motion exercises for a few minutes each day and gradually begin to incorporate more intense exercise.

If exhaustion is felt the next day after exercising, the body is communicating that too much is being done. It may be necessary to take a day for rest. Gradually, strength and endurance will improve as the intensity of exercise in increased over time. Also, when the cause of lethargy is mental-health related, seeking psychological counseling can prove very beneficial. Having a counselor to confide in can assist one to determine a plan for care when experiencing lethargy. This can help one feel more control over their life which can dramatically improve outlooks.

Prevention & Prophylaxis

There are certain lifestyle changes that can be made to prevent feelings of lethargy and are measures for self-care at home. Reducing stress is necessary and can be done by developing a plan to limit or avoid overexertion and triggers of emotional stress. Each day one should allow sufficient time to relax. Limits of ones capabilities need to be recognized as well. If asked to do tasks that could potentially cause feelings of stress, one should say no without having feelings of guilt.

Actions may be necessary to improve sleeping habits to prevent feelings of lethargy. Having a routine is helpful, this involves going to bed and waking at the same time each day. Daytime napping, caffeine, nicotine, and alcohol should be limited as well. Keeping activity on an even level and incorporating exercise can also prevent lethargy. Allow for a few minutes each day to get up and move, this could be a walk, some stretching exercises, bicycling, or engaging in recreational activities of choice. In the morning, people awaken from a state of fasting. This means going several hours without nourishment.

Eating breakfast is essential to maintain proper glucose levels which can prevent feelings of fatigue. A healthy breakfast should consist of lean protein, complex carbohydrates, and healthy fats. This provides for lasting energy and increases metabolism. Continuing to incorporate healthy food choices into lunch and dinner menus is also necessary to prevent feelings of lethargy that could occur later in the day due to lack of proper nutrition.

Retrieved from "http://medlexi.com/Lethargy"