by Allison Meier on. Sharpest ever view of the Andromeda (courtesy NASA/ESA Hubble Space Telescope). The NASA/ESA Hubble Space Telescope has released the largest ever image of the Andromeda galaxy, opening up 100 million stars and star clusters to public exploration. Itâs also the sharpest view of Andromeda, the closest galaxy thatâs a spiral like our own Milky Way, ever taken.
Dizziness or light-headedness when standing up occurs as a result of abnormal blood pressure regulation. Normally, when people stand, gravity causes blood to pool in the veins of the legs and trunk. This pooling lowers the blood pressure and the amount of blood the heart pumps to the brain. Low blood flow to the brain causes the dizziness and other symptoms.
But health problems can occur when blood pressure drops suddenly and the brain is deprived of an adequate blood supply. This can lead to dizziness or lightheadedness. Sudden drops in blood pressure most commonly occur in someone who's rising from a lying down or sitting position to standing. This kind of low blood pressure is known as postural hypotension or orthostatic hypotension. Another type of low blood pressure can occur when someone stands for a long period of time.