High blood sugar, also known as hyperglycemia, occurs when the body has too little insulin, or cannot use it properly. Common causes of high blood sugar include overeating, under-exercising and emotional stress.

The cells in your body need oxygen to carry out metabolism and produce enough energy to live and support your activities. Red blood cells are responsible for picking up oxygen from your lungs, transporting it in your bloodstream and delivering it to cells that need it.

White blood cells are an important part of your immune system. MedlinePlus states that white blood cells, also known as leukocytes, help combat infection and may be one of five distinct types, including neutrophils, basophils, eosinophils, monocytes or lymphocytes.

Donating blood is a valuable gift that can save lives. In fact, millions of people in the United States need blood transfusions each year. If you’re a smoker, you might worry about whether you can smoke before or after donating blood.

There’s a saying that “blood is thicker than water,” but blood that is too thick can be a serious medical issue.

Grapes and raisins contain the sugars glucose and fructose, which impart the sweet flavor of these foods. The high carbohydrate content, however, may concern you in terms of the potential effect on your blood sugar level.

Low platelets in infants can have a variety of causes and multiple effects. The clinical name for low platelets is thrombocytopenia, and indicates a platelet count of less than 150,000 per microliter of blood.

The body produces two main categories of white blood cells, granulocytes, cells containing granules suspended within their plasma and agranulocytes which have no granules. Neutrophils, eosinophils and basophils are types of granulocytes. Lymphocytes and monocytes are agranulocytes.

High blood sugar during pregnancy is referred to as gestational diabetes. This condition affects 3 to 5 percent of American pregnant woman and is associated with hormonal changes that occur in the body during pregnancy, according to the Cleveland Clinic.

The human body has approximately 5 liters of blood circulating at any given time, consisting of cells and plasma, notes the Franklin Institute. The liquid portion of blood is the plasma and the solid portions of blood are blood cells.

White blood cells play a key role in defending the body against invading bacteria and viruses. When white blood cell levels become too low, a condition known as neutropenia, an individual may become more susceptible to infection. A number of diseases are known to lower white blood cell numbers.

Donating blood is a safe and fulfilling way to give community service and assist in saving lives. The American Red Cross states that one person's blood donation can save up to three individuals' lives. All donors must meet the eligibility requirements in order to donate blood.