Lack of Energy

General or Other | General Practice | Lack of Energy (Symptom)


Lack of energy can be described as tiredness, weariness, lethargy or fatigue. It can be accompanied by depression, decreased motivation, or apathy. Lack of energy can be a normal response to inadequate sleep, overexertion, overworking, stress, lack of exercise, or boredom. When part of a normal response, lack of energy often resolves with rest, adequate sleep, stress management, and good nutrition.


Persistent lack of energy that does not resolve with self-care may be an indication of an underlying physical or psychological disorder. Common causes include allergies and asthma, anemia, 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.

Patterns and symptoms of lack of energy may help you discover its cause. 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 lack of energy could be due to heart or lung problems.

Persistent fatigue 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. Other symptoms, such as cognitive difficulties, prolonged exhaustion and illness after activity, muscle or joint pain, sore throat, headache, and tender lymph nodes, are common.

Lack of energy may accompany other symptoms affecting the heart or lungs including: Abnormal heart rhythms (arrhythmias), Chest pain, Cough, Rapid heart rate (tachycardia), Shortness of breath, Wheezing (whistling sound made with breathing)