What causes dizziness, blacking out, and fainting when standing up from a squat? What should I do?
Sep 16, 2025
Source: Cainiu Health
Dr. Tian Hongbo
Introduction
Arrhythmia, an abnormal heart rhythm caused by disordered electrical activity in the heart, reduces cardiac output. This insufficiency worsens during postural changes such as squatting to standing, leading to inadequate cerebral blood supply and resulting in dizziness or fainting. Symptoms often include palpitations, chest tightness, and shortness of breath; severe cases may be life-threatening. Treatment, under medical supervision, includes antiarrhythmic medications such as propafenone hydrochloride tablets, metoprolol tartrate sustained-release tablets, and amiodarone tablets to restore normal heart rhythm.
Dizziness, blacking out, and fainting upon standing up from a squatting position may be caused by orthostatic hypotension, sudden standing after prolonged squatting, anemia, hypoglycemia, arrhythmia, and other conditions. These symptoms can usually be managed through general treatments, medications, or other methods. If abnormalities occur, prompt medical attention is recommended. Specific analyses are as follows:
1. Orthostatic hypotension: When squatting, blood accumulates in the lower limbs. Upon sudden standing, delayed blood pressure regulation leads to transient cerebral ischemia and hypoxia, triggering symptoms. It is advisable to rise slowly in daily life—sit up for a moment before standing—and avoid rapid changes in posture. Increasing fluid intake appropriately may also help.
2. Sudden standing after prolonged squatting: Prolonged squatting compresses blood vessels in the lower limbs. Upon sudden standing, blood redistributes rapidly, temporarily reducing cerebral perfusion and causing dizziness or fainting. Slowing down movements when changing positions and avoiding prolonged squatting can effectively reduce the occurrence of such episodes.
3. Anemia: Insufficient hemoglobin levels in the blood reduce oxygen-carrying capacity. During postural changes like standing up from squatting, brain oxygen supply becomes further inadequate, leading to dizziness and vision darkening, often accompanied by pallor, fatigue, and palpitations. Treatment should follow medical advice and may include ferrous fumarate tablets, ferrous succinate tablets, and vitamin C tablets to supplement iron and enhance absorption. Additionally, increasing dietary intake of iron-rich foods such as lean meat and spinach is recommended.
4. Hypoglycemia: Low blood glucose levels fail to provide sufficient energy to the brain. Symptoms worsen during postural changes like standing up, accompanied by palpitations, cold sweats, and hunger. Immediate treatment involves sugar supplementation, such as oral glucose solution. Maintaining regular meals and using glucose powder under medical guidance can help prevent hypoglycemic episodes.
5. Arrhythmia: Electrical disturbances in the heart cause abnormal heart rhythms, reducing cardiac output. During postural changes like standing up, cerebral blood flow insufficiency worsens, resulting in dizziness and fainting, often accompanied by palpitations, chest tightness, and shortness of breath. Severe cases may be life-threatening. Treatment requires medications such as propafenone hydrochloride tablets, metoprolol tartrate sustained-release tablets, and amiodarone tablets under medical supervision to correct heart rhythm.
In daily life, maintain a regular routine, balanced diet, and avoid excessive fatigue and fasting. Develop the habit of moving slowly when getting up, and regularly monitor blood pressure and glucose levels. Seek immediate medical evaluation if dizziness or fainting occurs frequently, or if symptoms such as chest pain or difficulty breathing accompany these episodes.
