Plasma is the liquid portion of the blood. This slightly yellow fluid is made up of 90 percent water, according to the Franklin Institute. Although often thought of as less important than the cells of the blood that carry oxygen and provide immunity, the plasma is equally important.

Anything that contains a liquid, including the bloodstream, has a measurable pH level. This level, which determines the potential of hydrogen reactions, or the presence of oxygen, can have significant impacts on the human body.

There are two major types of protein in your blood -- albumin and globulin. The majority of blood serum protein is albumin, manufactured by your liver and used for healing, tissue growth and to prevent blood from leaking out of your blood vessels.

White blood cells, or leukocytes, are the cells your body uses to fight off infections. There are different types of white blood cell, each responsible for fighting different microbes. For example, neutrophils help fight off bacterial infections, while lymphocytes increase during viral illnesses.

Follicle stimulating hormone or FSH is one of the most important hormones in a woman's reproductive health, according to Just Mommies, a website devoted to providing accurate fertility information to women. FSH is produced by the pituitary gland and needed for ovulation to occur.

Blood potassium levels are closely regulated since both high and low levels can have life-threatening consequences. A normal potassium blood level is typically 3.5 to 5 milliequivalents per liter, or mEq/L. The normal range may vary slightly among testing laboratories, however.

A low blood count, also known as anemia, is a lower than usual number of red blood cells in your body. Anemia is particularly common among older individuals.

Links have been established between high levels of LDL cholesterol and coronary heart disease. Diet and exercise are the two primary recommendations of ways to lower LDL cholesterol, also known as "bad cholesterol."

Poor circulation most often occurs in the legs and feet but can also affect the arms and hands. Poor circulation can be caused by numerous illnesses, including heart disease, Raynaud’s disease, blood clots and diabetes.

Blood circulation is vital for your body's survival. Blood transports oxygen, fuel and nutrients to all organs of the body, including the brain. It also moves toxins and waste products to the appropriate organs for excretion. When blood flow to your brain is disrupted, you can succumb to a stroke.

Low blood circulation usually indicates arteriosclerosis, or hardening of the arteries. Atherosclerosis dominates as the most common type of arteriosclerosis. This disease involves stiffening and narrowing of medium and large arteries due to fat-rich deposits called plaques.

A blood clot in the thigh disrupts normal blood flow through the affected leg, which can lead to serious complications. Most thigh blood clots occur in the deep veins, a condition known as deep venous thrombosis (DVT). Less commonly, a clot can form in a thigh artery, depriving the leg of oxygen-rich blood.