However, CS creates dynamic conditions that expose blood to air, suction and additional exposures to plastic surfaces. These factors may cause a pronounced inflammatory response, hemolysis and activation of certain coagulation and humoral factors in blood that has been exposed to conditions created by CS.

The transfer of oxygen into the blood is through simple diffusion. The oxygen molecules move, by diffusion, out of the capillaries and into the body cells. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries.

Gas exchange takes place in the millions of alveoli in the lungs and the capillaries that envelop them. As shown below, inhaled oxygen moves from the alveoli to the blood in the capillaries, and carbon dioxide moves from the blood in the capillaries to the air in the alveoli.

The circulatory system delivers oxygen and nutrients to cells and takes away wastes. The heart pumps oxygenated and deoxygenated blood on different sides. The types of blood vessels include arteries, capillaries and veins.

Hemoglobin bound to oxygen absorbs blue-green light, which means that it reflects red-orange light into our eyes, appearing red. That’s why blood turns bright cherry red when oxygen binds to its iron. Without oxygen connected, blood is a darker red color.

red

reddish-brown

Over time, spilled blood that starts out red turns darker and darker as it dries, and its hemoglobin breaks down into a compound called methemoglobin. As time passes, dried blood continues to change, growing even darker thanks to another compound called hemichrome.

Brown blood is usually present toward the end of your cycle. As your body sheds the uterine lining in the first few days of your cycle, the blood is normally red. However, near the end of your cycle, the discharged blood is older and can be discolored.

Brown discharge, or brown spotting, can quite often occur after your period. It’ll usually last for roughly two days, but may come at any point throughout your cycle, for any duration of time.

If you are constantly having brown discharge or spotting and it’s bothering you, ask your OB/GYN. They may consider prescribing a new birth control method with higher estrogen that can help stop the spotting. Hormonal contraception can also help manage chronic menstrual pain from conditions like PCOS or endometriosis.

Brown — May happen right after periods as your body is “cleaning out” your vagina. Old blood looks brown. Spotting blood — This may occur mid-cycle or when ovulating. Sometimes early in pregnancy you may have spotting or a brownish discharge at the time your period would normally come.

This is perfectly normal, and it’s your uterus’s way of cleaning itself out when your flow is light. This discharge can last for a couple of days after your period is over. This is usually a dark brown discharge that lightens over time. Although rare, some people experience very light brown discharge during ovulation.

Spotting is a form of vaginal bleeding. It occurs between periods and is so light that it should not cover a panty liner or sanitary pad. Most people notice spotting as a few drops of blood on their underwear or toilet paper when wiping. In most cases, spotting should not cause concern.

Bleeding that occurs early in pregnancy is usually lighter in flow than a menstrual period. Also, the color often varies from pink to red to brown. The majority of women who experiencing spotting during pregnancy go on to have a healthy pregnancy and baby.

It becomes tender during pregnancy and could be a bit inflamed or irritated. This type of bleeding can also occur prior to a miscarriage or with an ectopic pregnancy, but most often it is not a cause for concern. Heavier bleeding during the first trimester can also be a sign of a miscarriage or ectopic pregnancy.