Lethargy is a medical condition characterized by drowsiness, slowness, general indifference, or tiredness. The condition may also be called malaise, fatigue, or listlessness. While lethargy may be a response to stress or overexertion, it can also be a symptom of many serious illnesses and problems.

Some lifestyle and dietary choices can lead to lethargy. These include failing to drink enough fluids and eating heavy foods such as whole milk ice cream and red meat. Staying in bed for too long and failure to get up and move around can make a person feel lethargic as well. Conversely, drinking water regularly, eating healthy, and exercising can battle feelings of lethargy.

Certain medications have been known to cause lethargy as a side effect. Some of these include calcium gluconate, Crystodigin, Digitaline, digitoxin, and Kalcinate. In addition, combinations of certain medications can cause lethargy. Typical drug interactions that can lead to lethargy include Lanoxin and Cardioquin, Lanoxin and Quinaglute, Lanoxin and Quinidex, and Trizivir and acyclovir. This list is not exhaustive. Therefore, a person taking medication should consult with his or her doctor to determine whether lethargy is a possible side effect.

A variety of diseases and disorders are also associated with lethargy. Acute and chronic kidney failure, jaundice, and hepatitis can all cause lethargy. Thyroid disorders, including hypothyroidism and autoimmune thyroid diseases, are also associated with lethargy.

Even psychological disorders can cause a person to experience lethargy. Bipolar disorder, depression and other depressive disorders, and dysthymia can each be responsible for lethargy. Similarly, life changes such as menopause, as well as shock, can cause one to feel lethargic.

Common illnesses, such as constipation, can also lead to lethargy. Numerous other serious diseases, such as Addison’s disease, Chagas disease, meningitis, and opsoclonus myoclonus are associated with symptoms of lethargy. Additional disorders and diseases that may cause lethargy include bronchiolitis, gastritis, enterocolitis, discitis, and myxedema.

Since the diseases and disorders associated with lethargy are so varied, it is important to take it seriously when the symptom presents itself. Although it may be caused by something simple, such as constipation or simple lack of sleep, lethargy can also be a sign of a potentially fatal illness.