Blood

"Blood is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal. Blood is mostly liquid, with numerous cells and proteins suspended in it, making blood ""thicker"" than pure water. The average person has about 5 liters (more than a gallon) of blood.
A liquid called plasma makes up about half of the content of blood. Plasma contains proteins that help blood to clot, transport substances through the blood, and perform other functions. Blood plasma also contains glucose and other dissolved nutrients.
About half of blood volume is composed of blood cells:
• Red blood cells, which carry oxygen to the tissues.
• White blood cells, which fight infections.
• Platelets, smaller cells that help blood to clot.
Blood is conducted through blood vessels (arteries and veins). Blood is prevented from clotting in the blood vessels by their smoothness, and the finely tuned balance of clotting factors."

Blood Infection

Medically, blood infection is known as sepsis or septicemia. In simple terms, it can be described as poisoning of the blood. It occurs due to presence of bacteria in the blood. When there is a small number of bacteria in the blood, the immune system is strong enough to destroy them. However, these bacteria multiply at a rapid pace when the immune system is weak, and release toxins that spread to various parts of the body and damage its tissues and organs. It is a serious medical condition that can cause a septic shock where the blood pressure becomes extremely low and the condition becomes life-threatening. hough the most common cause of this infection is bacteria; virus and fungi can also be responsible for it. These microbes get the scope to enter your body from unwashed hands or unsterilized equipment in the hospital. Some viral or fungal infections in the organs can spread into the blood stream and increase the level of toxins in the blood. This mostly happens in cases of lung infections like pneumonia, urinary tract infections (UTI), ruptured appendix, cellulitis, meningitis, etc.