There are more reasons for sudden dizziness during pregnancy, as follows: 1, may not sleep well during pregnancy, there may be dizziness after waking up; 2, the uterus increases during pregnancy, sleep lying position will compress the body’s large blood vessels, and when you get up, the brain blood supply is insufficient to cause postural hypotension, which should be noted when dizziness immediately sit down or lie down slightly, can be quickly relieved; 3, hypoglycemia: dizziness will occur when eating less; 4, if frequent dizziness to go to the neurology examination to exclude cranio-cerebral pathology, most people occasionally dizziness need not worry too much.