How much blood you draw will not affect your health.

Generally, pumping 200-300ml of blood will not affect your health. Pay attention to a normal diet after blood donation, and don't deliberately supplement it.

Blood is a red opaque viscous liquid flowing in human blood vessels and heart. Blood consists of plasma and blood cells. One liter of plasma contains 900-9 10g of water, 65-85g of protein and 20g of low molecular weight substances. Low molecular weight substances contain many electrolytes and organic compounds. Blood cells include red blood cells, white blood cells and platelets.