Many elderly people suffer from chronic cerebral blood supply deficiency and cerebral atherosclerosis, which cause dizziness and weakness during the day. Some elderly people also experience dizziness, lack of energy and weakness due to heart disease, resulting in a decrease in heartbeat output. Some young people who stay up all night, sleep poorly or stay up all night may also experience dizziness and weakness during the day. Some people may also suffer from nausea, vomiting, gastrointestinal flu, diarrhea and other symptoms that lead to electrolyte disorders and hypokalemia, which may also cause dizziness and weakness.