Extreme fatigue, weakness, or lethargy
If you have kidney disease, you may experience difficulty concentrating and severe fatigue or weakness. This happens because the kidneys are unable to effectively filter waste and toxins from the blood. These impurities build up in the blood [2] and trigger cause several symptoms.
Depending on the severity of the kidney damage, you may also develop anemia as a complication. Anemia itself is a cause of lethargy and fatigue. A hormone produced by the kidneys plays a role in triggering red blood cell production [3]. If the production of this hormone (erythropoietin) becomes impaired due to kidney damage, red blood cell production might fall, resulting in anemia. The red blood cells carry oxygen, which is critical for muscle and brain function.