What Happens To Your Body If You Lose A Lot Of Blood?

Depending on how squeamish you are, losing blood might be a pretty disconcerting experience. From a nosebleed to menstruation, losing blood can be a natural part of life. In some cases, however, losing blood can mean a critical emergency, like in the case of an accident or illness. How much blood can you actually lose, and what happens if you lose too much?

Our blood is actually a sticky, thick fluid and usually about 100.4 degrees Fahrenheit, a little higher than our body temperature, according to the Institute for Quality and Efficiency in Health Care. Blood is necessary to transport oxygen from the lungs to the cells of the body. The cells then use the oxygen for metabolism and produce carbon dioxide, which is carried back to the lungs through the blood and exhaled. Blood also supplies the cells with nutrients, carries hormones, and eliminates waste through other organs.

The amount of blood we have depends on our age and size, according to MedicalNewsToday. On average, an adult has about 10.5 pints, or 5 liters, of blood in the body. An average-sized female will have a little less, and an average-sized male will have a little more. Children have about 1.2 fluid ounces of blood per pound of body weight, so a child who weighs 60 pounds would have a little over 2 liters of blood.

Look for these signs of excess blood loss

There isn't an exact amount of blood you can lose before experiencing adverse effects, as it depends on how much blood you have to begin with (via Healthline). The body can compensate for certain things like donating blood, which is typically giving about one pint, or childbirth, which equates to losing 500-1000 milliliters.

If you lose 15-30% of your blood volume, you might begin to feel side effects, like nausea, increased heart rate, low blood pressure, and anxiety. Losing 30-40% of your blood volume will induce a traumatic response. Your blood pressure will drop further and your heart rate will continue to increase. You might feel confused or disoriented, your breathing might become shallow, and you may pass out.

Beyond 40%, the body won't be able to sustain itself on its own without treatment. The organs will begin to fail without proper blood supply and you'll faint, possibly slipping into a coma. Once you've lost 50%, your body won't be able to pump blood anymore. Your heart will stop pumping, organs will shut down, and death will be likely. In some cases, a blood transfusion may be effective in treating the condition, though if blood loss is over 40% or poorly controlled, it may not help.