Constant exhaustion, constant tiredness, lethargy, chronic listlessness: there are many names for listlessness and almost as many possible causes that can be explained directly or indirectly with an illness. Mental illness such as depression or a phobia such as trypophobia often lead to listlessness, tiredness and listlessness. This also applies to seasonal winter depression, which only occurs in the cold season. If it is not a serious mental or physical illness that can be held responsible for the lack of drive, the number one cause is stress. In addition to oxygen, the human body primarily needs water and food, but through eating disorder lead to problems: the body compensates for short-term nutritional deficits with reserves. However, if these are used up, the energy balance can falter in the long term and lead to massive listlessness. In addition, there are a number of physical illnesses as a cause for severe lack of drive over a longer period of time - for example chronic fatigue syndrome or diseases of the thyroid gland. If you have other symptoms, you should have your doctor clarify all the possibilities. Also the iron deficiency is often associated with listlessness. It is estimated that 10 percent of the male and 20 percent of the female population suffer from an undersupply, which leads to a variety of problems. You can find out whether you are suffering from an iron deficiency with a blood test from your doctor. Diabetes and other diet-related diseases can also lead to loss of drive and energy.