When any tissue in the body is injured there is a degree of swelling that results from bruising, chemical release and healing. But the brain is inside an enclosed skeletal shell, the skull.

Stomach cramps are one of the most unpleasant, uncomfortable problems associated with running. During a run, cramps or stitches can seriously hamper your performance. If the cramping continues hours after running, however, it can lead to more serious problems.

Irritable bowel syndrome, also referred to as IBS, causes your intestines to contract slower or faster than normal. Due to the difference in the way your bowels constrict, this can cause your large intestine to create gas, pain, cramping and sudden bouts of diarrhea or constipation.

Caffeine is a stimulant that occurs naturally in tea and cocoa and is added in generous amounts to many beverages for the sole purpose of providing bursts of energy and staving off fatigue. Researchers have been trying to understand the effects of caffeine for decades.

Zyrtec, or cetirizine, is an antihistamine drug used for the treatment of seasonal allergies and its symptoms, such as rhinitis (runny or stuffy nose), cough and allergic skin manifestations like atopic dermatitis or urticaria.

Minerals in the body that carry electrical charges are called electrolytes. Your urine, blood and other bodily fluids carry electrolytes through your body. When electrolyte levels become imbalanced, you can experience a range of symptoms ranging from headaches and nausea to confusion and dehydration.

How acid or how alkaline your digestive system is can affect how well your food is digested. This is measured using the pH scale, with lower numbers indicating an acid environment and higher numbers indicating an alkaline environment.

A healthy, balanced diabetes diet should include plenty of nonstarchy vegetables and moderate amounts of whole grains, fruits, starchy vegetables, lean protein and low- or nonfat dairy, says the American Diabetes Association.

Strength training and bodybuilding place a lot of stress on your body. Heavy weights that cause you to strain more than normal can affect your blood pressure and heart rate.

Itchy scalp has multiple causes, ranging from skin conditions such as dry skin, dandruff and psoriasis to underlying health concerns like iron deficiency anemia and liver disease. However, if your scalp begins to itch after shampooing, you may be experiencing a different set of conditions.

While most women are aware of what can cause hair to become dry, limp, oily or brittle, few know what can cause your scalp -- an important factor in the overall health of your hair -- to become itchy.

Sciatic nerve flossing is done to "massage" the sciatic nerve when it becomes compressed by the muscles and bones, which is a condition known as sciatica, says the Mavenlive website.