1, caused by vestibular dysfunction of the inner ear. Vestibule is located inside the ear and is one of the main sensory organs to regulate human balance. The vestibule can adjust the posture of the human body at any time and place through the neuromotor system, and maintain the balance of the human body. Compared with other sports, swimming changes its posture more frequently and belongs to a whole-body exercise. When the position of the human body in the water changes frequently, the balance organs in the body sometimes cannot be adjusted with the frequent changes of the body posture, which will lead to dizziness and abdominal distension of swimmers. In addition, if swimmers get water in their ears, stimulating vestibular nerves will also lead to dizziness and bloating.
2. Severe hypoxia in brain tissue leads to the redistribution of blood in the body during swimming. When the blood flow in the body is relatively small, the blood volume of limbs muscles will increase significantly. Viscera and brain, especially for people who don't swim often, swimming suddenly and violently will lead to a sharp increase in oxygen consumption of the human body, and the brain tissue will be difficult to adapt for a while, resulting in an increase in aerobic capacity, causing severe ischemia in the body, especially in the brain tissue, thus making swimmers feel dizzy and swollen.