Dizziness and blackness after standing up after squatting for a while may be related to postural hypotension, or it may be caused by iron deficiency anemia, hypoglycemia and other reasons. 1. Postural hypotension: when squatting, the lower limbs are in a tense state, and the blood supply to the brain is relatively high. After standing up suddenly, due to the effect of gravity, the blood flows rapidly to the lower limbs, resulting in insufficient blood supply to the brain, which causes dizziness and blackness in front of the eyes. 2. Anemia: Due to insufficient blood volume, the ability of blood to carry oxygen is weakened, causing the brain to be in a chronic state of oxygen deprivation. When squatting and standing up, it is easy to cause the symptoms of insufficient blood supply and oxygen supply to the brain to be aggravated, which will cause dizziness and blackness in front of the eyes. 3. Hypoglycemia: low blood sugar itself, squatting for a while after standing up, hypoglycemia attack, there will be dizziness and black symptoms, may also be accompanied by fatigue, sweating and other symptoms. Dizziness and blackness after standing up after squatting for a while may also be caused by other reasons, if the symptoms are frequent and recurring, you should consult a doctor as soon as possible to confirm the diagnosis of the cause of the targeted treatment.