For a healthy adult, the percentage of blood in the body is typically around 7-8% of their body weight. This means that a person who weighs 70 kg (154 pounds) would have about 5-6 liters (1.3-1.5 gallons) of blood in their body.
However, the amount of blood needed for a person to be considered healthy can vary depending on their individual circumstances. For example, a person who has lost a significant amount of blood due to injury or surgery may need a blood transfusion to restore their blood volume and maintain healthy oxygen levels. The amount of blood needed for a transfusion can also vary depending on the individual’s weight, age, and medical condition.
In general, maintaining a healthy blood volume is important for overall health and well-being. The body relies on a consistent supply of oxygen and nutrients that are transported through the blood, and any significant loss of blood can lead to serious health complications. If you are concerned about your blood volume or have experienced significant blood loss, it is important to seek medical attention promptly.