Lethargy, Fatigue and Tiredness
Head | General Practice | Lethargy, Fatigue and Tiredness (Symptom)
Lethargy can be described as tiredness, weariness, fatigue, or lack of energy. It can be accompanied by depression, decreased motivation, or apathy. Lethargy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, or boredom. When part of a normal response, lethargy often resolves with rest, adequate sleep, decreased stress, and good nutrition. Persistent lethargy that does not resolve with self-care may be an indication of an underlying physical or psychological disorder.
Common causes include allergies, asthma, anaemia, cancer and its treatments, chronic pain, heart disease, infection, depression, eating disorders, grief, sleeping disorders, thyroid problems, medication side effects, alcohol use, or drug use.
The cause of lethargy may be suggested by its pattern and accompanying symptoms. If it starts in the morning and lasts all day, it could be due to lack of sleep or depression. If it develops as the day passes and is accompanied by dry skin, constipation, cold sensitivity, and weight gain, it may be caused by an underactive thyroid gland. The combination of shortness of breath and lethargy could be due to heart or lung problems. Persistent lethargy with no clear diagnosis may result from chronic fatigue syndrome, which can start with a flu-like illness and is often not relieved with rest.
Lethargy may accompany other symptoms that vary depending on the underlying disease, disorder or condition. Lethargy is a nonspecific symptom, so identifying other symptoms may be helpful in determining its cause. Lethargy may accompany other symptoms affecting the heart or lungs including: abnormal heart rhythms, chest pain, cough, rapid heart rate, shortness of breath, wheezing.
Diagnosis and Treatment
The first step in establishing the cause of lethargy is an examination by a physician. Diagnostic testing may be necessary in order to assign a definitive diagnosis. These tests may include blood and urine tests, imaging tests, and, in some cases, referral to a specialist. The treatment and prognosis of lethargy depend on the underlying cause.